JPH04216373A - Reproduced data processor - Google Patents

Abstract

PURPOSE:To enable a quick access to discrete informations and a highly stable reproduction for continuous informations by providing a 1st clock producing means, 2nd clock producing means, and switching means, etc. CONSTITUTION:The reproduced signal from an optical head 3 is inputted to a reproduction amplifier 6 and a magneto-optical signal Ps is outputted to the 1st clock producing circuit 9, etc., then a 1st read-out clock (fr) is produced and supplied to one of the inputs of 1st switching circuit 10. A 2nd read-out clock (fr') produced by the 2nd clock producing circuit 11 is supplied to another input of the circuit 10. When the reproduction command is given from a host device, a selection of read-out clock from a memory 15 is made through a controller 17 and circuit 10. That is, when the reproduced information is the discrete information of data for computer, etc., the clock (fr) is selected and the quick access is performed, and in the case of the continuous information such as a musical information, etc., the clock (fr') is selected, then the highly stable reproduction is attained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproduction data processing apparatus for reproducing recorded information from a recording medium such as a compact disk on which information such as digitized audio signals and computer data is recorded.

0002

2. Description of the Related Art Conventionally, compact discs (hereinafter referred to as CDs) on which continuous information such as music information is recorded as digital signals using optically detectable minute pits have been widely used. In addition, focusing on the large capacity and productivity of this CD, we have developed a CD-ROM (Compac) that records not only music but also discrete information such as computer data.
t DiskRead Only Memory) is also beginning to become popular (hereinafter, for convenience of explanation, CD-ROM
(will also be included on the CD). These CDs can only be played by a playback-only optical disc playback device (CD
playback is performed by a player).

FIGS. 7 and 8 are schematic diagrams for explaining the signal format used in CDs. As shown in FIG. 7, one frame 50a of the recording signal is a frame synchronization signal indicating the beginning of the frame. 50b, a subcode 50c indicating additional data information, and a data field 50d which is 24 bytes of main information and an 8-byte parity code for error detection and correction. Note that the data field 50d is CIRC (Cr
oss Interleaved Reed Solom
It consists of an error detection and correction method that combines non-complete interleaving called on code).

Further, as shown in FIG. 8, 98 of the above frames 50a form one subcoding frame (hereinafter referred to as sector) 51a, and each frame 50a
The subcode 50c in 0a constitutes one subcoding block 51c for 98 frames, and the data in this subcoding block 51c determines the track number (if the main information is music information, the song number) and the information on the disc. absolute address information etc. are displayed.

[0005] Since the above sector length is 13.3ms, 7
5 sectors equals 1 second. The sector number indicating the number of the sector on the disk is represented by a combination of "minute": "second": "number within one second (00 to 74)". This sector number constitutes continuous time information and position information that increase sequentially from the innermost circumference of the disk.

FIG. 9 is a schematic diagram showing the arrangement of areas on a CD. The disk 52 includes a main information recording area 52b that includes main information such as music information and sector numbers based on the subcodes, and a TOC (Table O
f Contents ) area 52a. This TOC area 52a includes a main information recording area 52b.
Additional information indicated by subcodes for each main information recorded in the , such as each track number and recording start sector number of each track, and whether audio information such as music or computer data is recorded on that track. Information such as identifying whether or not the person is present is recorded.

[0007] According to the above format, the CD player reads out the subcode information in the TOC area 52a when loading the disc, thereby determining the number of each piece of main information (equivalent to the number of songs in the case of music information) and the number of pieces of main information. The sector number of the recording start position and the type of information (audio or data) are recognized. Then, in response to subsequent playback instructions, playback of the desired track is promptly executed with an access operation by checking the information in the TOC area 52a and the sector number based on the subcode in the main information recording area 52b. be done.

These CDs are recorded at a constant linear velocity, so-called CLV (Constant Linear Velocity).
Since the information is recorded using the location method, the recording density is constant at any position on the disk, which is suitable for improving the recording capacity. And C
In the D player, CLV in the above signal format.
C that controls the rotation of the disc so that the interval between recorded CD playback signals, such as frame synchronization signals, matches the standard length.
LV control is executed.

FIG. 10 is a block diagram showing the configuration of a conventional CD player, in which a spindle motor 62 that supports a CD disk 61 is controlled by a CLV control circuit 63.
The CD disk 61 is controlled to rotate at a constant linear velocity. Then, the optical head 64 is moved to a desired position on the CD disk 61 by a moving mechanism (not shown).

When a reproducing light beam is irradiated onto the CD disk 61 through this optical head 64, the strength of the reflected light is converted into an electrical signal, which is further amplified by a reproducing amplifier 65 and sent to the first clock generating circuit as a reproducing signal. 66 and a reproduction data processing circuit 67.

The first clock generation circuit 66 is a so-called PLL (Phase Locked Locator) which generates a clock synchronized with the reproduction signal from the reproduction amplifier 65.
OP). Further, the reproduced data processing circuit 67 uses the clock generated by the first clock generation circuit 66 to determine the reproduced signal, separates the frame synchronization signal, and converts the EFM (Eight to Four
demodulates the reproduced data that has been modulated using the modulated modulation method (teen Modulation). After that, a CIRC decoding operation is performed using the memory 72 to correct errors included in the reproduced signal.

[0012] Here, the clock system for processing the reproduced data will be described in detail. Regarding the write operation to the memory 72 after the EFM demodulation of the reproduced data, it is necessary to use a clock synchronized with the reproduced signal. , the write address generation circuit 68 is supplied with the clock generated by the first clock generation circuit 66, and memory addresses synchronized with this clock are sequentially output from the write address generation circuit 68. By giving this memory address to the memory 72 via the switch 71,
The EFM demodulated data in the reproduced data processing circuit 67 is written into the memory 72 in a predetermined order.

On the other hand, regarding the read operation from the memory 72, a second clock generation circuit 69 is provided which generates a clock having a predetermined reference frequency. A memory address is generated by a read address generation circuit 70 operated by the reference clock generated by this circuit 69, and this memory address is sequentially given to the memory 72 via a switch 71, so that the read address generation circuit 70 operates from the memory 72 in a predetermined order. Data reading is performed.

Of this read data, a portion corresponding to the main data shown in FIG. 8 is converted back to analog audio information by a D/A converter 73 and output to a terminal 74.

Note that the above write address generation circuit 68
The address generation circuit 70 and the read address generation circuit 70 do not have the same address generation order, and also perform deinterleaving to return data rearranged by interleaving during disk recording to the original order.

Furthermore, since the actual capacity of the memory 72 is finite, the CLV control circuit 63 performs minute control over the spindle motor 62, for example, during the playback signal, so that there is no excess or deficiency in writing or reading data to or from the memory 72. Continuous playback is guaranteed by sequentially controlling the frame synchronization signal period of the second clock generation circuit 69 so that it becomes the reference period of the system of the second clock generation circuit 69.

Furthermore, by using a reference clock different from the clock synchronized with the reproduction signal as the address generation clock in the read address generation circuit 70, fluctuations in the disk rotation system included in the reproduction signal can be absorbed. , high-fidelity audio is played back without time axis fluctuations. This is usually TBC (Time Bass)
e Correcting), and is an outstanding feature of digital audio equipment.

Next, the control procedure during the access operation in the CD player having the above configuration will be explained with reference to the flowchart shown in FIG.

When reproduction is instructed by a user's instruction or the like, first, the optical head 64 is moved to the specified absolute address position for starting reproduction on the disk (S31 and S32).
. When the movement of the optical head 64 is completed, a still jump (one return jump per rotation of the disk) is performed to keep the light beam stationary at the disk radial position and in a standby state (S33), and then CLV control is performed. Turn on (S34). Thereafter, the process waits until the disc linear velocity reaches a predetermined value (S35), and when the predetermined value is reached, the process waits at that disc radial position until the absolute address value of the reproduction start target is obtained (S36). This is commonly referred to as disk rotation latency. Then, at the stage when the absolute address value of the playback start target is obtained, the still jump operation is turned off (S37), and then the playback operation is started.

Next, based on FIG. 12, an example of changes in the disk rotational speed, disk linear velocity, and reproduction signal synchronization clock due to the above control will be described, taking as an example an access operation from the outer circumference side to the inner circumference side of the disk. List and explain.

During periods m2 and m3 during which the optical head 64 is moved from time t1 when the reproduction instruction is issued, the rotational speed of the disk is maintained at almost the same rotational speed as during the period m1 before receiving the reproduction instruction. Therefore, the disk linear velocity is
It gradually decreases as the optical head 64 moves toward the inner circumference of the disk. Further, the reproduction signal synchronization clock gradually decreases during a period m2 up to t2 in the middle, following the disk reproduction signal, and during a period m3, it is out of the PLL lock range and is in a holding state.

Thereafter, from the CLV control start time t3 after the movement of the optical head 64 is completed, the disk rotation speed and the disk linear velocity gradually increase, and after a time period of m4 and m5, the disk rotation speed and the disk linear velocity increase at the time of t5. Reach rotational speed and linear velocity within a predetermined range. During this period, the reproduction signal synchronization clock increases following the reproduction signal from time t4 after a holding period m4. Furthermore, after a period m6 corresponding to the disk rotation waiting time, the reproduction operation is started.

[0023] In this way, general CAV (Const
Compared to conventional floppies or hard disks, etc., which reproduce information at a constant angular velocity (i.e., constant rotation speed) using the Angular Velocity method,
In the CLV method, in addition to the head movement time and rotation waiting time, the reproduction operation is started after a time waiting by controlling the linear velocity of the disk and waiting for further rotation.

By the way, when recording and using various information such as music information and computer data on rewritable disks such as magneto-optical disks, which have been developed in recent years, there are differences between them and conventional CDs. It is desired to standardize the playback method and configure a compatible disk recording/playback device.

[0025] In this case, in the initial disc on which no information is recorded, the absolute address information using the subcode according to the above-mentioned CD signal format and the CL
Since the frame synchronization signal used for V control does not exist, access operations to arbitrary sector positions prior to recording and CLV control necessary during recording cannot be performed. Therefore,
As an absolute address recording method equivalent to the absolute address information using the subcode, after bi-phase mark modulation of the absolute address, the guide groove of the optical disc is moved inward in the radial direction of the disc depending on whether each bit is "1" or "0". It has been proposed to bias the guide groove outward, or to change the width of the guide groove (for example, Japanese Patent Laid-Open No. 64-39
(See Publication No. 632, etc.).

In this case, if the frequency band of the absolute address by bi-phase mark modulation and the frequency band of recorded information by EFM modulation are made different, it is possible to reproduce the two separately from each other, and the recorded information can be reproduced separately. Access operations can be performed even to areas where there is no area, using the above-mentioned absolute address using the guide groove. Further, regarding CLV control, accurate CLV control is possible by using the reproduced carrier component of the above-mentioned absolute address, and can be similarly performed during recording.

[0027] Since such a reproduction data processing apparatus using a CD has a large capacity, it is desirable to be able to quickly access and reproduce desired various information from the recording medium. In addition, playback data processing devices using rewritable discs that are compatible with CDs are characterized by high speed because they are discs, and can be used as information recording media for home use, especially for storing a wide variety of information in addition to music information. It is also desired that information be reproduced in a reliable and quick manner.

[0028]

[Problems to be Solved by the Invention] However, when trying to reproduce the above information using the conventional method described above, the waiting time required for the so-called access operation to move the optical head to a desired position on the disk is high. In addition to this, a waiting time is required to control the number of rotations of the disk to achieve a predetermined linear velocity, resulting in the problem that prompt playback operations cannot be performed.

The waiting time associated with the above-mentioned rotational speed control is generally longer than the time required to move the optical head, and especially when the moving distance is from the innermost circumference to the outermost circumference of the disk (or
(from the outermost circumference to the innermost circumference), the rotation speed ratio at each position becomes 2:1 or more, resulting in an increase in access time. This is not so much of a problem when the information to be played back is auditory information such as music information, but when the information is discrete, particularly small in volume, and requires frequent playback instructions, such as computer data, the above-mentioned wait is required for each playback. This time consuming process results in a reduction in computer processing capacity. Furthermore, even if the drive capacity for moving the optical head is improved for the purpose of improving the access speed, it will ultimately be dominated by the rotation control waiting time and the rotation waiting time, making it impossible to achieve an overall improvement in access speed. It becomes something that does not exist.

FIG. 13 is a diagram for explaining further problems when the above-mentioned CD format is used for a recordable disc.

[0031] Reproduction when recorded information exists in five sectors from sector (n) to sector (n+4) for sector row (a) on a disk having a unique absolute address value indicated by pre-recorded information. It shows the operation. (b) is a reproduced signal, which includes parts other than the above five sectors, namely sector (n-1) and sectors (n+5) to (
n+7) is an area where no information is recorded. This reproduction signal (b)
becomes a binary reproduction signal (c) using a comparator etc., but
Information unrecorded areas (n-1) and (n+5) to (
At n+7), the reproduced signal (b) has a noise level, and the corresponding binary reproduced signals (c1) and (c3) become meaningless data containing high frequency components. Therefore, as shown in (d), the PLL for clock generation synchronized with the reproduced signal also generates a binary reproduced signal (c).
In an attempt to follow this, a high frequency clock is generated in the area where no information is recorded (the vertical axis is the frequency).

Here, in response to the TBC operation in the above explanation, since the memory write clock (e) is a clock synchronized with the reproduced signal, (e1) and (
The area e3) is written to the memory using a high frequency clock. Since the memory read clock (f) is a reference clock with a predetermined frequency, the frequency difference between the memory write clock (e) and the memory read clock (f) is (
g). Therefore, depending on the capacity of the memory, a so-called memory overflow phenomenon occurs in which new playback data is written before the playback data that has been written is read out. (h) shows how memory overflow is detected (high level indicates memory overflow state).

On the other hand, the sector to be reproduced is (n
) to (n+4), but a predetermined delay time occurs as the data on the disk is reproduced and written to the memory, and the CIRC performs deinterleaving and error correction operations, and (i) As shown in (n
) to (n+4) sectors are read out from the memory with a delay corresponding to (d1) to (d5), respectively.

Therefore, during the memory read operation of data (d5), a memory overflow occurs at the point where the level shifts from low to high as shown in (h), and the portion of data (d5) existing on the memory is destroyed. However, this may cause a problem of causing an error.

The present invention has been made in view of the above-mentioned problems, and its purpose is to make it possible to more quickly reproduce information recorded on a recording medium, and to, for example, eliminate unrecorded portions of information. The object of the present invention is to provide a playback data processing device that can ensure highly reliable playback processing without being affected by unnecessary signals in the area even if they exist, and that further provides a playback data processing device that is capable of ensuring highly reliable playback processing even if continuous information such as music information is processed as computer data. It is an object of the present invention to provide a reproduction data processing device capable of performing quick and reliable reproduction even when the information is mixed with discrete information such as.

[0036]

[Means for Solving the Problem] Therefore, in the reproduced data processing device according to claim 1 of the present invention, the reproduced data is written into the memory means using a write clock synchronized with the reproduced data from the recording medium. The reproduced data processing device includes a first clock synchronized with the reproduced data as a read clock for reading the reproduced data from the memory means.
The device is characterized in that a first clock generation means for generating a read clock is provided.

[0037] Furthermore, the reproduced data processing device according to claim 2 comprises:
In the apparatus of claim 1, the second
a second clock generating means for generating a read clock; a switching means for selectively selecting one of the first read clock and the second read clock as the read clock; The present invention is characterized by further comprising read clock switching control means for controlling the switching operation of the switching means based on identification information indicating whether continuous information or discrete information is recorded.

[0038]

[Operation] According to the reproduced data processing apparatus of claim 1,
Reproduction data is written into the memory means using a write clock synchronized with reproduction data from the recording medium, and reading is performed using a first read clock synchronized with reproduction data. Therefore, conventionally, after the movement of the optical head was completed, the reproduction operation could not be started until the disk rotation reached a predetermined linear velocity corresponding to the clock generated at the reference frequency. After the movement of the head is completed, it is possible to start the reproducing operation immediately, and the access time is shortened. Furthermore, since writing and reading are performed based on clocks that are mutually synchronized with the reproduced data, overflow in the memory means is suppressed, thereby improving the reliability of the reproduction operation.

Further, according to the reproduction data processing device of claim 2, when the information to be reproduced is continuous information such as music information, the readout clock is automatically changed to the second readout clock having a predetermined reference frequency by the switching means. can be switched to This ensures a reproducing operation without time axis fluctuations due to TBC operation, as in the prior art. Therefore, discrete information such as computer data can be accessed more quickly, and both different information formats can be reproduced with high reliability.

[0040]

[Example] Regarding one embodiment of the present invention, FIGS. 1 to 6
The explanation based on this is as follows.

As shown in FIG. 5, the magneto-optical disk 1, which is a rewritable recording medium, has a T.
OC (Table Of Contents) area 1
A is provided, and most of the area outside the TOC area 1a is an information recording area 1b. In addition to music information, various information such as characters, images, and code data are recorded in the information recording area 1b, while in the TOC area 1a, additional information regarding each piece of information recorded in the information recording area 1b,
For example, the starting sector position and ending sector position of each piece of information, identification information as to whether it is music information or computer data, etc. are recorded. The signal format used here is the same as that shown in FIGS. 7 and 8 used in the description of the conventional example, so its description will be omitted.

In the TOC area 1a and the information recording area 1b, as shown in FIG. 6, spiral guide grooves 2...
(hatched portions in the figure) are formed at predetermined intervals in the disk radial direction. Then, depending on whether the absolute address on the disk is "1" or "0" after biphase mark modulation,
The guide grooves 2 are biased toward the inside or outside of the information recording area 1b in the radial direction. Note that the above absolute address represents the position on the disk, and also represents the CLV (Const
This is pre-recorded information as rotation control information (Ant Linear Velocity). Furthermore, since the absolute address here corresponds to one sector in the CD format, it will be referred to as a sector hereinafter.

As shown in FIG. 1, the reproduction data processing device for reproducing information recorded on the magneto-optical disk 1 includes a spindle motor 4 that supports and rotates the magneto-optical disk 1, and a spindle motor 4 that supports and rotates the magneto-optical disk 1. The optical head 3 is equipped with an optical head 3 that irradiates laser light onto the target and outputs a reproduction signal according to the reflected light.

The reproduction signal from the optical head 3 is transmitted to the reproduction amplifier 6.
The signal is input to the reproducing amplifier 6, amplified and binarized, and output as a magneto-optical signal PS. This magneto-optical signal PS is supplied to a first clock generation circuit 9 which also functions as a first read clock generation means, a reproduced data processing circuit 16 and a pre-recorded information detection circuit 7.

The prerecorded information detection circuit 7 includes, for example, a bandpass filter and a PLL (Phase Locked Loop).
), and the PLL generates a clock synchronized with the pre-recorded information in the reproduced signal extracted by the band-pass filter. and,
A clock synchronized with the pre-recorded information consisting of bi-phase mark modulation of absolute address information is connected to the CLV control circuit 5.
supplied to

The CLV control circuit 5 compares the synchronized clock from the prerecorded information detection circuit 7 with an internally held reference frequency (synchronized with the clock of the second clock generation circuit 11, which will be described later). However, by controlling the spindle motor 4 using the difference signal, accurate CLV control is implemented.

Further, the pre-recorded information in the reproduced signal extracted by the pre-recorded information detection circuit 7 is supplied to the address detection circuit 8. This address detection circuit 8 consists of a biphase mark demodulation circuit and an address decoder, and after performing biphase mark demodulation of prerecorded information, the address decoder decodes it into position information on the disk, that is, an absolute address value that is a sector. A signal is generated and supplied to the controller 17 which also functions as a read clock switching control means.

On the other hand, the first clock generation circuit 9 to which the binary magneto-optical signal PS from the reproduction amplifier 6 is inputted,
Write address generation clock fw and read address generation clock synchronized with binary magneto-optical signal PS (
A first read clock) fr is generated by a PLL,
The write address generation clock fw is supplied to the write address generation circuit 13, and the read address generation clock f
r is respectively supplied to one input of the first switching circuit 10 as a switching means, the details of which will be described later. The other input of the first switching circuit 10 is supplied with a read address generation reference clock (second read clock) fr' generated by a second clock generation circuit 11 as a second read clock generation means. It has become.

The first switching circuit 10 selects either the read address generation clock fr or the read address generation reference clock fr' as the clock necessary for read address generation according to instructions from the controller 17. It has a function of selectively selecting and supplying it to the read address generation circuit 12.

Further, the reproduction data processing circuit 16 to which the binary magneto-optical signal PS from the reproduction amplifier 6 is inputted,
Separation of frame synchronization signal from binary magneto-optical signal PS and EFM (Eight to Fourteen M
demodulation), and separates the subcode information and sends it to the controller 17, and also stores the main data and parity as playback data in the memory (memory means) 1.
5, and using the playback data in memory 15, CIRC
(Cross Interleaved Reed S
olomon Code). The memory address operation here is the same as that described in the conventional example. That is, by giving the memory address generated by the write address generation circuit 13 via the second switching circuit 14, the reproduced data is written to the memory 15 in a predetermined order in conjunction with the operation of the reproduced data processing circuit 16. At the same time, the memory address generated by the read address generation circuit 12 is given via the second switching circuit 14, thereby performing an error correction operation and corrected reproduction using the reproduction data written in the memory 15. Read and send data to the playback data processing circuit 1
This is performed in a predetermined order in conjunction with the operation in step 6.

The playback data error-corrected by the playback data processing circuit 16 on the memory 15 is converted back to an analog audio signal by the D/A converter 18 and sent to the external terminal 2.
0 to the outside, or is transferred to a host device connected to the terminal 21 via the interface 19.

The controller 17 receives the terminal 2 from the host device.
1. Reproduction instructions are received via the interface 19. It also has an access function that recognizes the position of the optical head 3 on the disk by receiving absolute address information from the address detection circuit 8, and moves the optical head 3 to a desired position using an optical head moving mechanism (not shown). , recognizes subcode information given from the reproduced data processing circuit 16. Furthermore, as described above, it also has the function of instructing selection of the first switching circuit 10.

FIG. 2 shows the write address generation clock f
FIG. 2 is a block diagram illustrating in more detail the first clock generation circuit 9 that generates clock w and read address generation clock fr. An example in which both clocks fw and fr are generated with different frequencies will be described below.

In the first clock generation circuit 9, the binary magneto-optical signal PS supplied from the reproduction amplifier 6 is passed through a first phase comparator circuit 31 and a first LPF (Low Pass Filter).
ter ) 32, 1st VCO (Voltage Con
The output signal is input to a first PLL composed of a trolled Oscillator) 33. A write address generation clock fw is output from the first VCO 33, and this clock fw is used by the write address generation circuit 1 as described above.
3, and is also supplied to the first phase comparison circuit 31 and the first frequency divider 34 within the first clock generation circuit 9. The first phase comparator circuit 31 generates an error signal by comparing the phases of the binary magneto-optical signal PS and the write address generation clock fw, and this error signal is smoothed by the first LPF 32 and the first VCO 33 is supplied as a control voltage. Therefore, this first PL
In the state where L is locked, the write address generation clock fw becomes a synchronous clock that follows the binary magneto-optical signal PS.

On the other hand, in the first frequency divider 34 to which the write address generation clock fw is input, the frequency is divided by 1/N1, and the second phase comparison circuit 35 is used as the clock fa.
supplied to This second phase comparison circuit 35 and the second LP
F36, second VCO37, and second frequency divider 38
A read address generation clock fr is output from the second VCO 37, and this clock f
r is supplied to the first switching circuit 10, and the clock fb having the same frequency as the output clock fa of the first frequency divider 34 is divided by 1/N2 by the second frequency divider 38. The signal is then supplied to the second phase comparator circuit 35. The second phase comparison circuit 35 generates an error signal by comparing the phases of the clocks fa and fb, and this error signal is smoothed by the second LPF 36 and supplied as a control voltage to the second VCO 37. Therefore, the first and second P
When LL is locked, the read address generation clock fr becomes a synchronous clock that follows the binary magneto-optical signal PS.

[0056] To give an example of the frequency of each of the above clocks fw and fr, the write address generation clock f
The frequency of w (at a predetermined linear velocity) is 4.32, which is the channel bit frequency during EFM modulation of CD.
18 MHz (98 times the digital audio information sampling frequency), the frequency of the read address generation clock fr (however, at a predetermined linear velocity) and the read address generation reference clock fr' is generally determined by the CD playback signal processing LSI. 4.2336 MHz (96 times the digital audio information sampling frequency), which is often used in At this time, the first frequency divider 34 and the second frequency divider 3
The frequency division ratio of 8 is 1/98 and 1/96, respectively, and the inputs fa and fb of the second phase comparison circuit 35 are 44.1 KHz, which is the digital audio information sampling frequency.
becomes.

Next, the control procedure during the access operation performed by the controller 17 will be explained with reference to the control flowchart shown in FIG.

A playback instruction from the host device is given from the terminal 21 and sent to the controller 1 via the interface 19.
7, the controller 17 first determines whether the instructed reproduction information is audio information such as music or computer data (S11). Although the determination here may be made based on the instruction content from the host device, the controller 17 itself may be configured to identify it using additional information based on subcode information read in advance from the TOC area 1a of the magneto-optical disk 1. is also possible, which can improve reliability.

In S11 above, if it is determined that the reproduced information is computer data, the read address generation clock supplied from the first switching circuit 10 to the read address generation circuit 12 is changed to the first clock generation clock. A clock is selected in the first switching circuit 10 so that the clock fr is output from the circuit 9 (
S12).

Next, the optical head 3 is moved to the designated absolute address position on the disk for starting reproduction (S13 and S14). Then, when the playback start position is reached, C
LV control is turned on (S15), and reproduction of information is immediately started (S16). Note that although the CLV control is turned on at the time of S15, this is just a procedure for convenience of explanation, and the CLV control may be turned on at any time before or after the optical head 3 is moved.

On the other hand, if it is determined in S11 that the instructed reproduction information is audio information such as music, the output of the first switching circuit 10, that is, the read address generation clock 2. The first switching circuit 1
0, the clock is selected (S17).

Thereafter, the processing from S18 to S24 is carried out in the same manner as the steps S31 to S37 described above with reference to FIG. 11, and then reproduction of the audio information is started.

[0063] The operation when the above processes from S12 to S16 are executed will now be described with reference to FIG. 12, which was used earlier in the description of the conventional example.

A clock synchronized with the reproduction signal is generated during and after the period m2·m3 from time t1 when the reproduction instruction is received to time t3 when the optical head 3 reaches the target absolute address position. The period m4 up to the time t4 is the same as in the conventional case, but in this embodiment, it is possible to start reproducing information at the time t4. At this time, although the disk rotation control has not reached the predetermined rotational speed and predetermined linear velocity as in the conventional case, the read address generation circuit 12 receives the magneto-optical signal PS on the disk generated by the first clock generation circuit 9. Since the read address generation clock fr synchronized with
Replay operations are performed immediately without causing memory overflow.

In the conventional device, the period m5 after the above t4 is
In addition to the waiting time required by the disk rotation control, information reproduction was started at time t6 after waiting for the disk rotation for a period m6. Waiting time is no longer necessary.

FIG. 4 is a chart showing the reproduction operation of the above-mentioned apparatus corresponding to the conventional example shown in FIG. 13. Signals similar to those in FIG. 13 will be described with similar symbols.

In the figure, (a) shows a sequence of sectors on the disk that have unique absolute address values indicated by pre-recorded information, and records are made in five sectors from sector (n) to sector (n+4). While the information exists, as shown in the reproduced signal (b), sectors (n-1) other than the above five sectors,
Sectors (n+5) to (n+7) are areas where no information is recorded. The reproduction signal (b) is converted into a binary magneto-optical signal (c) by the comparator in the reproduction amplifier 6, but the information is not recorded in sectors (n-1), (n+5), ... (n+7).
In this case, the reproduced signal (b) has a noise level, and the corresponding binary magneto-optical signals (c1) and (c3) become meaningless data containing high frequency components.

Therefore, the first clock generation circuit 9
, P for clock generation synchronized with the reproduced signal
LL also tries to follow the binary magneto-optical signal (c),
As shown in (d) in the figure, a high frequency clock is generated in the information-unrecorded area (the vertical axis is shown as frequency).

Here, in order to correspond to the TBC operation described above, since the write address generation clock (e), which is the clock for memory writing, is implemented with a clock synchronized with the reproduced signal, (e1) and (e3) The area is written to the memory using a high frequency clock. However, at this time, the read address generation clock fr synchronized with the magneto-optical signal Ps on the disk is replaced by the read address generation clock (f
), there is no frequency difference (meaning the number of bytes of main information per unit time) between the memory write clock (e) and the memory read clock (f), and therefore, no memory overflow phenomenon occurs.

As explained above, in the above embodiment, the reproduction of discrete information such as computer data takes the time required for CLV control accompanying the access operation and the subsequent rotational waiting time until the absolute address position to start reproduction. The reproduction data processing apparatus can be started as quickly as a reproduction data processing apparatus using a conventional CAV recording medium without requiring a reproducing data processing apparatus, and has a high-speed access function. Furthermore, it is possible to play back multimedia recording media on which continuous information such as conventional music information is mixedly recorded. Furthermore, if the performance of the driving means for moving the optical head is improved in order to speed up the access operation, it is possible to obtain the effect without adjusting the performance of the CLV control system. Furthermore, in CLV rotation control, the spindle motor and its control system do not need to be compatible with high speed, so the cost of the reproduction data processing device can be reduced. Further, even if there is an unrecorded portion of information on a recordable disc or a rewritable disc, highly reliable reproduction data processing can be performed without being affected by unnecessary reproduction signals in that area.

Although the above embodiment has been described as a reproduction data processing apparatus using a rewritable magneto-optical disk, reproduction data of a conventional reproduction-only disk on which computer data etc. are recorded, that is, a CD-ROM It is also possible to use it as a processing device.

[0072] Also, although the configuration has been described as having a function of reproducing continuous information such as music information, claim 1 of the present invention
Within this range, it may be only discrete information obtained by compressing computer information or music information, and in that case, the second
The clock generation circuit 11 and the first switching circuit 10 can be made unnecessary. Furthermore, the format of the absolute address does not matter as long as it is pre-recorded and recognizable information.

Furthermore, although the above embodiment has been explained using a magneto-optical disc-shaped recording medium, reproduction data processing using other rewritable recording media and recording media on which information can be recorded only once is also possible. The present invention is applicable to a device, and is not limited to a disk format, and can be implemented with a card-shaped recording medium without departing from the gist of the present invention.

[0074]

As described above, the reproduced data processing device according to claim 1 of the present invention is capable of performing reproduction in which the reproduced data is written into the memory means using a write clock synchronized with the reproduced data from the recording medium. The data processing device is provided with a first clock generating means for generating a first read clock synchronized with the reproduced data as a read clock for reading the reproduced data from the memory means.

[0075] As a result, while conventionally the reproduction operation could not be started until the disk rotation control reached a predetermined linear velocity after the completion of the optical head movement, the reproduction operation can be started immediately after the optical head movement operation. It is now possible to start. As a result,
In addition to enabling faster access, since writing and reading are performed based on clocks that are synchronized with the playback data, overflow in the memory means is suppressed, thereby improving the reliability of playback operations. be effective.

[0076] Furthermore, the reproduced data processing device according to claim 2 includes:
a second clock for generating a second read clock at a predetermined reference frequency;
a clock generating means; a switching means for selectively selecting one of the first read clock and the second read clock as the read clock; The configuration is further provided with read clock switching control means for controlling the switching operation of the switching means based on identification information indicating which of the above is recorded.

[0077] As a result, discrete information such as computer data can be accessed more quickly, and when the information to be reproduced is continuous information such as music information, TBC operation is used as in the past. This has the effect that a reproduction operation without time axis fluctuation is ensured, and that highly reliable reproduction can be performed in both different information formats.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a reproduced data processing device in an embodiment of the present invention.

FIG. 2 is a block diagram of a first clock generation circuit in the reproduced data processing device.

FIG. 3 is a flowchart showing a control procedure during information reproduction in the reproduction data processing device.

FIG. 4 is a timing chart showing a signal form during information reproduction in the reproduction data processing device.

FIG. 5 is a schematic plan view of a magneto-optical disk on which recorded data is reproduced by the reproduced data processing device.

FIG. 6 is an enlarged plan view of the magneto-optical disk.

FIG. 7 is a schematic diagram showing the format of a frame signal recorded on a conventional compact disc.

FIG. 8 is a schematic diagram showing the sector format of the compact disc.

FIG. 9 is a schematic plan view showing an information recording area on the compact disc.

FIG. 10 is a block diagram showing the configuration of a conventional CD player that plays the compact disc.

FIG. 11 is a flowchart showing a control procedure when reproducing information in the CD player.

FIG. 12 is a timing chart showing the operating state of the CD player when reproducing information.

FIG. 13 is a timing chart showing a signal form when information is reproduced by a conventional reproduction device for a magneto-optical disk.

[Explanation of symbols]

1 Magneto-optical disk (recording medium) 9 First clock generation circuit (first read clock generation means) 11 Second clock generation circuit (second read clock generation means) 10 First switching circuit (switching means) 15 Memory (memory means) ) 17 Controller (read clock switching control means)
fr Read address generation clock (first read clock) fr' Read address generation reference clock (second read clock)

Claims (2)

[Claims] 1. A reproduced data processing device for writing the reproduced data into a memory means using a write clock synchronized with the reproduced data from a recording medium, wherein the reproduced data is read from the memory means. A reproduced data processing device characterized in that a first clock generating means is provided for generating a first read clock synchronized with the reproduced data as a read clock of the reproduced data. 2. A second clock generating means for generating a second read clock at a predetermined reference frequency; and a second clock generating means for generating the second read clock by selectively selecting one of the first read clock and the second read clock. and read clock switching control means for controlling the switching operation of the switching means based on identification information indicating whether continuous information or discrete information is recorded in a predetermined area of the recording medium. 2. The reproduced data processing apparatus according to claim 1, wherein: