JPH05217276A - Disk player - Google Patents

Abstract

PURPOSE:To simplify and ensure the detection of the diameter of a reproducing disk by switching the rotation of the disk from a rated speed to a prescribed high speed and detecting a switching time between these two speeds. CONSTITUTION:At the time of starting reproduction, the disk 1 is driven by a motor servo circuit 3 according to a rated speed servo constant for a small diameter disk and set to a servo constant by the detective output of a TOC reading detection means 20. Further, a clock regenerative circuit 15 is set for a high speed and the rotation of the disk 1 is started by the servo constant of a small size disk. On the other hand, a timer means 22 starts to count a time and the timer is set so as to arrive at a high speed before a set time is ended to count in the case of a small size disk and after a set time is ended to count in the case of a large size disk. Then the count result of the timer means 22 and a high speed detection signal from a high speed detection means 23 are supplied to a disk discrimination means 24 and the diameter of the disk is discriminated by the order of generation of two signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to store reproduced data in a memory once and then read it at a rated speed, and read digital signals recorded on a disk at a speed higher than the rated speed while repeating the same part. The present invention relates to a disc player capable of re-reading erroneous reproduction data for reproduction.

[0002]

2. Description of the Related Art First, the applicant of the present application rotates a disc at a speed higher than a rated speed, traces the disc at a high speed with a pickup, reads a digital signal recorded on the disc, and demodulates the digital signal to obtain the signal. The main data such as music information is written in the memory at high speed in response to the high speed rotation of the disc, and then the main data is read from the memory in accordance with the rated speed, and the amount of data in the memory While managing
In order to repeatedly read the same portion of the disc repeatedly, a disc player has been proposed in which the trace position of the pickup is sequentially advanced to perform reproduction (see Japanese Patent Application No. 2-319984). In this disc player, because the disc is traced at high speed, it is not possible to correct the error in the reproduced main data by creating the time to trace the same part repeatedly while reading the main data from the memory at the rated speed. Alternatively, it is possible to reread the digital signal containing the main data that could not be read correctly when the reproduction of the main data was interrupted due to an external shock or swing. Therefore, by providing such a function, it is possible to provide a disc player excellent in anti-vibration measures, and it is suitable for a portable CD player such as a headphone stereo type or a portable type that is carried around and used.

By the way, a disc for a CD player (C
In D), as is well known, there is a so-called CD single having a diameter of 8 cm in addition to a standard CD having a diameter of 12 cm. Since there is a weight difference between the standard CD and the CD single,
There is a gap in the inertial mass when each disk is rotated.
Therefore, most of the CD players configured to reproduce the respective discs have a motor servo that controls the spindle motor for disc rotation drive by setting the inertial mass of the standard CD and the inertial mass of the CD single. The servo constant of the circuit is set.

By the way, in the disc player that reads the disc at a high speed as described above, the rotational speed of the disc becomes high, so that the difference in inertial mass due to the difference in weight of the disc increases. Therefore, in such a disc player, when discs with different diameters are supported, each disc must be stabilized unless the servo constant of the motor servo circuit is switched in accordance with the inertial mass of each disc. The rotation cannot be controlled.

[0005]

By the way, in an ordinary disc player which reads a disc at a rated speed, the diameter of the disc to be reproduced is discriminated to determine the disc size as shown in Japanese Patent Application Laid-Open No. 2-44566. It is known that the servo constant of the motor servo circuit is switched according to the diameter so that stable rotation control can be performed for each disk having a different diameter.

However, the disk player disclosed in the above publication has a problem that a sensor is required to detect the diameter of the disk, the number of parts is increased, and the structure is restricted.

[0007]

SUMMARY OF THE INVENTION The present invention, in a disc player for reading a disc at a high speed, solves the above-mentioned problems by selectively switching the disc reading speed between a rated speed and a high speed. A switching signal generating means for generating a switching signal, a spindle motor for rotating a disk, and a motor servo circuit in which a servo constant can be switched according to each of a large-diameter disk and a small-diameter disk, and the switching signal generation. Rotation control means for controlling the motor servo circuit to switch the rotation of the disk from the rated speed to the high speed in response to a switching signal from the means, and to start timing when the disk reading speed is switched from the rated speed to the high speed. , Measure the preset time according to the time required to start up the small diameter disc from the rated speed to the high speed. A high-speed detection unit is provided that includes a timer unit and a high-speed detection unit that detects that the disc is being read at a high speed. When it is detected that the high-speed reading is performed, the servo constant of the motor servo circuit is set corresponding to the small-diameter disk, and before the high-speed reading is detected by the high-speed detecting means. When the measurement of the set time by the timer means is completed, the servo constant of the motor servo circuit is set corresponding to the large-diameter disk.

[0008]

According to the present invention, in a disc player for reading a disc at a high speed, the disc can be rotationally driven by switching between a rated speed and a high speed. In the case of a small-diameter disc, the rated speed is switched to the high speed. Correspondingly, the preset time is timed by the timer means, and when the speed of the disk is switched from the rated speed to the high speed, the time counting by the timer means is started and the time counting by the timer means is finished. Determine the disc diameter that is set depending on which is earlier, the timing or the timing at which the high speed of the disc is detected.
According to the determination, the servo constant of the motor servo circuit is set for each disk.

[0009]

FIG. 1 shows an embodiment of the present invention, which is a portable CD.
FIG. 3 is a circuit block diagram of the player. In the illustrated CD player, the spindle motor 2 rotates at a rated speed in order to rotate the CD type disc 1 at a speed higher than the rated linear speed (for example, double speed) in addition to the rated linear speed. The motor servo circuit 3 for controlling the spindle motor 2 can selectively set the servo constants corresponding to each of the two types of speeds by switching the servo constant setting means 4. Is made in.

The illustrated CD player has a diameter of 12c.
A large-diameter disk (standard CD) having a diameter of m and a small-diameter disk (CD single) having a diameter of 8 cm can be reproduced, and the motor servo circuit 3 switches the servo constant setting means 4 so that the servo constant corresponding to each disk having a different diameter. It can be set selectively by.

In the figure, 5 is a pickup for optically tracing the disk 1 by the emitted light beam, and 6
Is an RF amplifier that amplifies an RF signal (high-frequency signal) of a digital signal recorded on the disc 1 obtained by tracing by the pickup 5 and shapes the waveform, and 7 is an RF amplifier obtained by the RF signal obtained through the RF amplifier 6. 5 is driven to perform focusing control for focusing the light beam tracing the disc 1 on the signal surface of the disc 1 and tracking control for causing the light beam to follow the signal track of the disc 1, and the pickup 5
Is a pick-up servo circuit for controlling the feeding of the disk in the radial direction of the disk 1.

Reference numeral 8 denotes a sync detection / E for detecting a frame sync signal indicating the beginning of a frame from the EFM-modulated recording signal of the disk 1 which is waveform-shaped by the RF amplifier 6 and is output as a digital signal, and for performing EFM demodulation.
An FM demodulation circuit 9 separates sub-code data indicating the beginning and music number of a music piece, elapsed playing time, etc. (P and Q codes) from various demodulated data EFM-demodulated by the synchronization detection / EFM demodulation circuit 8. A sub-code separation / Q-code demodulation circuit that demodulates the Q-code included in the sub-code data, and 10 is a parity that performs error detection and error correction of main data that is music information extracted from the digital signal after EFM demodulation. An error detection / correction circuit for performing error detection / correction of the main data by using, a first RAM for temporarily storing the demodulation data as a buffer for error correction of the main data, and a first RAM for storing the demodulation data as a main data error correction buffer. Write address for controlling the timing of writing demodulated data to the first RAM 11 and the timing of reading the demodulated data The first to generate a fine read address
An address generation circuit, 13 is the error detection / correction circuit 10
Is an interpolation circuit for interpolating main data that cannot be error-corrected according to the main data obtained before and after the main data.

In the figure, the synchronization detection / EFM demodulation circuit 8, the subcode separation / Q code demodulation circuit 9, the error detection / correction circuit 10, the first address generation circuit 12, and the interpolation circuit 13 which are surrounded by the one-dot chain line, A signal processing circuit 14 is provided for digitally processing a digital signal read from the disk 1 to obtain information data.

Reference numeral 15 is a clock regenerating circuit which is composed of a PLL circuit and regenerates a clock synchronized with a bit included in the digital signal output from the RF amplifier 6.

Here, each circuit constituting the signal processing circuit 14 performs each signal processing by the reproduced clock reproduced by the clock reproducing circuit 15. Since the write address and the read address generated from the first address generating circuit 12 are generated according to the timing of the reproduction clock, the jitter cannot be absorbed when the rotation speed of the disk 1 changes. But the 1st R
The AM 11 is prevented from overflowing. Further, since the reproduction clock obtained from the clock reproduction circuit 15 is generated according to the rotation speed of the disc 1, each circuit constituting the signal processing circuit 14 outputs from the disc 1 when the disc 1 is rotated at a high speed. Each signal processing is performed at a higher speed than a general CD player according to the signal reading speed of.

Reference numeral 16 is written with basic programs such as a disc reproducing method, various search methods, and a focusing 5 introduction method for the pickup 5 for performing various basic operation controls and a display (not shown). It is a system control circuit composed of a microcomputer for performing control for displaying and input control of operation keys (not shown).

The system control circuit 16 is provided with Q code monitoring means 17 for monitoring the Q code demodulated by the sub code separation / Q code demodulation circuit 9, and the trace position by the pickup 5 is set to the disk diameter. Track jump control means 1 for supplying a track jump signal for displacing in the direction to the pickup servo circuit 7.
8 are provided.

Further, the system control circuit 16 is written with TOC data (table of contents information used for signal search such as music selection and display on a display) when the lead-in area of the disk 1 is traced. The TOC memory 19, the TOC reading detecting means 20 for detecting the completion of reading the TOC data by detecting the TOC data written in the TOC memory 19, and the TOC reading detecting means 20 for reading the TOC data A switching signal generating means 21 for generating a high-speed switching signal for switching the reading speed of the disc from the rated speed to the high speed (twice the rated speed) when the completion is detected, and the TOC.
From the switching signal generation means 21 and the timer means 22 which starts the timing at the completion of reading the data and measures the preset time in accordance with the time required to start up the small diameter disc from the rated speed to the high speed. After the high-speed switching signal is generated, the sub-code separation / Q-code demodulation circuit 9 again demodulates the Q-code to detect high-speed detection means 23 and the timer means 22. The diameter of the disc 1 to be reproduced is discriminated depending on which is faster, the completion of the measurement of the set time by the disc or the detection of reaching the high velocity by the high velocity detection means 23, and the servo constant setting means 4 is set to the disc according to the discrimination. The disk discriminating means 24 is provided to switch the servo constant according to the diameter of 1.

Reference numeral 25 is a serial / parallel conversion circuit for converting the main data of the serial digital signal demodulated by the signal processing circuit 14 into a parallel digital signal, and 26 is the main data output from the serial / parallel conversion circuit 25. The second RAM, 27 is the second R
A second address generation circuit for generating a write address for controlling the writing of the main data to the AM 26 and a read address for the main data from the second RAM 26, and 28 is a crystal oscillation accuracy reference using a crystal oscillator 29. A reference oscillator for generating a clock, 30 is a frequency dividing circuit for frequency-dividing the reference clock generated by the reference oscillator 28 by half, and 31 is a circuit for selectively dividing the reference clock from the reference oscillator 28 through the frequency dividing circuit 30. Is a switching circuit for supplying to the motor servo circuit 3.

Here, the write address generated by the second address generation circuit 27 is generated in synchronization with the reproduction clock from the clock reproduction circuit 15, while the second write address is generated by the second address generation circuit 27.
The read address generated from the address generation circuit 27 is generated in synchronization with the reference clock from the reference oscillator 28, and is generated in accordance with the sampling frequency when recording the main data on the disk 1. Therefore, the main data write timing to the second RAM 26 is faster than the main data read timing from the second RAM 26, and the second RA
The jitter component at the output timing of the main data is absorbed by M26.

A second RAM 32 monitors a write address and a read address of the second address generation circuit 27.
While monitoring 26 overflows, error detection and
The occurrence status of the uncorrectable signal indicating that the information data from the correction circuit 10 cannot be corrected is detected, and the interpolation circuit 1 is detected based on the detected status.
The second R is determined by determining that it exceeds the interpolation capability of 3
A RAM control circuit that detects the timing at which the main data write to the AM 26 is stopped and restarted, and controls the second address generation circuit 27 according to the detection output to control the main data write to the second RAM 26. Further, the RAM control circuit 32 respectively generates an overflow signal indicating that overflow of the second RAM 26 is detected, and an interpolation ineffective signal indicating that when the overflow capacity of the interpolation circuit 13 is exceeded. The track jump control means 18 generates a track jump signal for returning the reading position (trace position) of the disc by the pickup 5 by one track.

Reference numeral 33 is a WOK signal generating means provided in the system control circuit 16 for generating a writable signal (WOK signal) indicating that the main data can be written in the second RAM 26. The WOK signal generation means 33 is WOK according to the generation of the overflow signal and the non-interpolable signal from the RAM control circuit 32, and according to the Q code monitoring status by the Q code monitoring means 17 and the operating status of the track jump control means 18. When a signal is generated, specifically, an overflow signal or a non-interpolable signal is generated, the WOK signal is not generated,
Further, the WOK signal is not generated at the same time as the generation of the track jump signal from the track jump control means 18, and the track jump ends, so that it is within the target range of the disc (within 3 frames before and after the target frame). When the Q code indicating that is detected, a WOK signal is generated.

Reference numeral 34 denotes a shift register (not shown) in which main data output from the serial / parallel conversion circuit 25 is written in synchronization with the timing of writing main data in the second RAM 26, and overflow of the second RAM 26 is detected. A latch circuit (not shown) for latching the main data written in the shift register, and the main data written in the shift register coincides with the main data latched in the latch circuit. Second RAM
26 is a data coincidence determination circuit that sets the timing for resuming the writing of the main data to 26.

Reference numeral 35 denotes a parallel / serial conversion circuit for converting main data of a parallel digital signal read from the second RAM 26 into a serial digital signal, and 36 denotes main data output from the parallel / serial conversion circuit 35 into an analog signal. It is a D / A converter.

Next, the operation will be described.

The motor servo circuit 3 is supplied with the digital signal obtained through the RF amplifier 6, the reproduction clock obtained from the clock reproduction circuit 15 and the reference clock obtained from the reference oscillator 28, and the motor servo circuit 3 is supplied.
Detects the pulse width of the shortest pulse in the digital signal,
The spindle motor 2 is subjected to speed control so that the pulse width becomes a predetermined length, and then the signals obtained by frequency-dividing the reproduction clock and the reference clock are compared in phase and phase servo is applied to the spindle motor 2. Although the disk 1 is rotated at a predetermined linear velocity by such a PLL operation, the CD player shown in FIG. 1 sets the servo constant of the motor servo circuit 3 by the switching signal generated from the disk discriminating means 24 in the initial state. The means 4 is set to the servo constant for the small diameter disc. Further, the clock recovery circuit 15 is set to the characteristic for the rated speed by the switching signal from the switching signal generating means 21, while the switching circuit 31 selects the reference clock from the reference oscillator 28 obtained through the frequency dividing circuit 30. The servo constant setting means 4 is set to the servo constant for the rated speed by these operations. Therefore, at the start of reproduction, the disk 1 is driven by the motor servo circuit 3 for a small-diameter disk and according to the servo constant for the rated speed.

Here, the servo constant of the servo constant setting means 4 is initially set for a small-diameter disc only when the servo constant is set for a small-diameter disc and a large-diameter disc is rotationally driven, but the startup is delayed. On the other hand, when the above servo constant is set for a large-diameter disk and a small-diameter disk is rotationally driven, the servo gain becomes excessive with respect to the inertial mass of the disk, the PLL operation becomes unstable, and the small-diameter disk runs away. This is because there is a risk of being rotated.

As described above, when the disk 1 is rotated at the rated linear velocity according to the servo constant for the small diameter disk,
The disc 1 is traced from the lead-in area, and the TOC data recorded in the lead-in area is read. The TOC data is read and the TOC memory 19
When stored in the
Since it is detected that the OC data has been read, a switching signal is generated from the switching signal generating means 21 according to the detected output, and the servo constant setting means 4 is set to the servo constant for high speed. Further, the clock recovery circuit 15 is set to the characteristic for high speed (double speed) by the switching signal from the switching signal generating means 21, while the switching circuit 31 selects the reference clock not through the frequency dividing circuit 30. Can be switched to. Therefore, the rotation of the disc 1 is started up so that the linear velocity becomes high with the servo constant for the small-diameter disc. Then, the program area in which main data such as music information is recorded is traced.

On the other hand, when the TOC reading detecting means 19 generates a detection output indicating that the TOC data has been read, the timer means 22 starts counting time. The time measured by the timer means 22 is set according to the time required to start up the small diameter disc from the rated speed to the high speed, and when the small diameter disc is rotated, it is set by the timer means 22. Before the time measurement is completed, the high speed is reached, and when the large-diameter disk is rotated, the timer means 2 is used.
According to 2, the high speed is reached after the set time is measured. When the rotation of the disk 1 reaches a high speed, the recording signal is read again from the disk 1, so that the sub code separation / Q code demodulation circuit 9 outputs a Q signal.
The code is demodulated so that the high speed detecting means 23 detects that the high speed has been reached.

When the timer means 22 completes the measurement of the set time, a time completion signal indicating the fact is supplied to the disc discriminating means 24, and the high speed detecting means 23 detects that the high speed is reached. A high speed detection signal indicating that is supplied to the disc discriminating means 24.
Then, the disc discriminating means 24 detects which of the time counting completion signal and the high speed detection signal is generated first, and when it is detected that the time counting completion signal is generated first, a large-diameter disc is detected. It is determined that there is, and the servo constant setting means 4 is switched to the servo constant corresponding to the large diameter disk,
On the other hand, when it is detected that the high speed detection signal is first generated, it is determined that the disc is a small-diameter disc, and the servo constant setting means 4 is kept as the servo constant corresponding to the small-diameter disc.

By the way, as described above, when a large-diameter disc is being reproduced, the rotation of the disc reaches a high linear velocity from the rated linear velocity due to the relationship of the servo constants of the motor servo circuit 3 in the initial state. Since the timer means 22 completes the measurement of the set time and the disc discriminating means 24 detects the timing completion signal first, it is switched to the servo constant corresponding to the large-diameter disc, and the servo constant is changed to the diameter of the reproducing disc. Is matched. On the other hand, when the small-diameter disc is being reproduced, the timer means 2 is operated after the disc rotation reaches the high linear velocity from the rated linear velocity.
The measurement of the set time is completed by 2 and the high speed detection signal is detected first by the disc discriminating means 24, so that the servo constant is switched to the servo constant corresponding to the small diameter disc, and the servo constant is matched with the diameter of the reproducing disc. ..

Therefore, when a large-diameter disc and a small-diameter disc are reproduced, both are rotated at a constant high linear velocity due to the servo constant set correctly, and the program area of each disc is stably maintained. Will be traced by the pickup 5.

In this way, each disk is rotated,
When the lead-in area and program area of each disc are traced by the pickup 5, the signal recorded on the disc is supplied to the RF amplifier 6 as an RF signal (high frequency signal) via the pickup 5. The RF signal is amplified by the RF amplifier 6, waveform-shaped, and supplied to the signal processing circuit 14 as a digital signal. Then, the signal processing circuit 14 demodulates the digital signal and extracts various data contained in the digital signal.

Here, when the lead-in area is traced, the subcode separation / Q code demodulation circuit 9 performs T
The OC data is demodulated, and the demodulated TOC data is stored in the TOC memory 19. The TOC memory 19
When the TOC data is stored in, the fact is detected by the TOC reading detecting means 20, the high speed switching signal is generated from the switching signal generating means 21, and the servo constant setting means 4 becomes the servo constant for high speed as described above. The motor servo circuit 3 is switched by switching the switching circuit 31.
The reference clock is supplied from the reference oscillator 28 without passing through the frequency dividing circuit 30, and the characteristics of the clock recovery circuit 15 are switched for high speed. Therefore, the motor servo circuit 3
Causes the drive speed of the spindle motor 2 to be switched, so that the disk 1 is driven at a predetermined high linear velocity,
When the program area is traced at that speed, the signal processing circuit 14 demodulates the main data (audio data), the error detection and error correction processing of the main data is performed, and the missing main data is lost. Data is interpolated. Then, the main data output from the signal processing circuit 14 is converted from a serial digital signal to a parallel digital signal by the serial / parallel conversion circuit 25, and then according to the write address from the second address generation circuit 27. Second RAM2
Written in 6. The main data written in the second RAM 26 is the second address generation circuit 27.
The main data is read according to the read address from, and the parallel-serial conversion circuit 35 converts the main data from a parallel digital signal to a serial digital signal. Then, the parallel / serial conversion circuit 3
The main data output from 5 is the D / A converter 3
The analog signal is converted by 6 and separated into stereo left and right channel components, which are respectively supplied to audio circuits (not shown) in the subsequent stages.

By the way, the write timing of the main data to the second RAM 26 is set to a high speed in accordance with the output timing of the main data from the signal processing circuit 14, but the read timing of the main data from the second RAM 26 is set to the disk. The second RAM 2 is adapted to the sampling frequency when storing the main data.
It is set to be slower than the writing timing for writing data to the data. Therefore, as the reproduction progresses, the second RAM 26 will eventually overflow.

Here, the overflow of the second RAM 26 is detected by the RAM control circuit 32 by monitoring the write address and the read address of the second address generation circuit 27, and the overflow signal from the RAM control circuit 32 indicates the overflow. Are supplied to the system control circuit 16. Therefore, the track jump control means 18 generates a track jump signal for returning the reading position of the disc by the pickup 5 for one track, and the trace position of the disc is returned by one track by the pickup 5 so that the same portion on the disc is repeated. Will be traced. In this case, the second R
Since the main data written so far is sequentially read from the AM 26, the main data is not interrupted,
Plays continuously.

When the overflow of the second RAM 26 is detected, the RAM control circuit 32 outputs a stop signal for stopping the writing to the second RAM 26 from that point, and the main data is stopped from being written to the second RAM 26. Therefore, only the reading of the main data is performed, and the amount of the main data written in the second RAM 26 decreases.

On the other hand, when the digital signal read by the pickup 5 is processed by the signal processing circuit 14, the Q code contained in the digital signal is monitored by the Q code monitoring means 17 at any time, and the Q code thereof is monitored. The code is stored in RAM (not shown) in system control circuit 16. Therefore, the Q code at the time when the second RAM 26 overflows is stored in the RAM in the system control circuit 16, so that when the second RAM 26 overflows, the track jump control means 1
8 is activated, the access operation is started, and the pickup 5
The trace position by 1 is returned by one track of the disk, and a search is performed with the Q code stored in the RAM in the system control circuit 16 as a target. And
The trace position by the pickup 5 approaches the digital signal portion including the Q code at the time of overflow,
Q code within the target range will be demodulated,
When the Q code is detected by the Q code monitoring means 17, the data coincidence determination circuit 34 receives the main data output from the serial / parallel conversion circuit 25.

Here, the data coincidence determination circuit 34 stores main data of a predetermined number of samples until the overflow of the second RAM 26 occurs, and when the main data from the serial / parallel conversion circuit 25 comes to be taken in. , The main data is compared with the main data stored in the data coincidence determination circuit 34.
Then, when a match of those main data is detected,
The coincidence signal indicating that is supplied to the RAM control circuit 32, and the writing of the main data to the second RAM 26 is restarted.

When the writing of the main data to the second RAM 26 is resumed, the resumed main data is next to the address where the final main data at the time when the writing was stopped due to the overflow in the second RAM 26 is stored. The data is sequentially written from the address, and is written subsequently to the final main data. And the second
The main data whose writing to the RAM 26 is resumed is
Since the final main data is continuous on the disc, correct reproduction is continuously performed.

On the other hand, when the coincidence signal is not obtained from the data coincidence determination circuit 34 for some reason, the RAM control circuit 32 determines the coincidence and timing of the write address and the read address from the second address generation circuit 27 and the timing in the second RAM 26. When it is detected that the main data becomes empty, the writing to the second RAM 26 is restarted. In this case, the read main data is not connected correctly, but the main data is transferred to the second RAM so that the reproduction is not interrupted.
The final main data in 26 is continuously written, and the newly written main data is continuously read from the final main data.

By the way, when the signal reading of the disc by the pickup 5 cannot be performed correctly due to external impact or swing, or scratch or dirt on the disc, the error detection / correction circuit 10 cannot correct the error of the main data. An uncorrectable signal is generated from the error detection / correction circuit 10. Then, when the RAM control circuit 32 detects that the uncorrectable signal is continuously generated for the interpolation ability of the interpolation circuit 13 or more, the RAM control circuit 32 generates the uninterpolable signal and the WOK signal generating means 33. WO
Generation of the K signal is stopped. Therefore, the second address generation circuit 27 is controlled via the RAM control circuit 32,
Writing of main data to the second RAM 26 is stopped, and a track jump signal for causing the pickup 5 to make a track jump to return the trace position of the disk is generated by the track jump control means 18, and main data that cannot be error-corrected is generated. The trace position of the disc by the pickup 5 is returned so as to retrieve the Q code of the digital signal block read immediately before the reading of the containing digital signal block.

Here, if erroneous main data is generated due to an impact or swing from the outside, the erroneous main data can be read again by tracing the same portion of the disk again by the pickup 5, and the correct main data can be read. Therefore, the data coincidence determination circuit 3
The same main data as the main data immediately before the error is input to 4, and the data coincidence determination circuit 34 generates a coincidence signal. The comparison of the main data by the data coincidence determination circuit 34 is not performed immediately after the track jump at the trace position is finished, but is performed near the frame including the final main data written in the second RAM 26. At this time, the Q code is detected with the frame including the Q code corresponding to the final main data as a target. In this case, even if the Q code is not detected in consideration of the failure of fetching the Q code, 1 The target frame is detected by adding one frame to the Q code time information stored at each timing when the frame is reproduced. Then, when the trace position reaches the vicinity of the target frame, main data for comparison is fetched into the data coincidence determination circuit 34,
The main data fetched by the data coincidence determination circuit 34 is compared.

When a match signal is generated by the data match determination circuit 34, a start signal is generated from the RAM control circuit 32 and correct main data is read continuously from the main data immediately before the erroneous main data. Will be written.

Therefore, in this case, the main data can be continuously reproduced without interruption.

On the other hand, if erroneous main data is generated due to scratches or stains on the disk, even if the same portion of the disk is traced again by the pickup 5, the erroneous main data cannot be read again, and the correct main data is reproduced. I can't get it. Therefore, the data coincidence determination circuit 34
No match signal is obtained from the RAM control circuit 3, and the main data in the second RAM 26 is only consumed.
2 eventually detects that the main data in the second RAM 26 becomes empty. When the detection is performed, the tracing of the same portion of the disk is stopped again, the track jump control means 18 is operated to trace the next portion, and the start signal is generated from the RAM control circuit 32. The writing of the main data to the 2RAM 26 is restarted. In this case, the re-read main data is not correctly connected to the main data written in the second RAM 26, but the main data should be written continuously to the final main data in the second RAM 26 so that the reproduction is not interrupted. The newly written main data is continuously read from the final main data.

[0047]

As described above, according to the present invention, in the disc player configured to read the disc at a high speed, the rotation of the disc is switched from the rated speed to a predetermined high speed, and these two are determined. Since the diameter of the reproducing disc is detected by the switching time between the different speeds, the disc diameter can be surely detected without providing a detection element such as a photo sensor. Further, in particular, in a disc player that reproduces a disc in which table-of-contents data, which is table-of-contents information of main data such as music information, is recorded at a predetermined location, the table-of-contents data is read at a rated speed and the main data is read at a predetermined high By reading according to the speed, the table of contents data can be read, and then the disk diameter can be detected during the series of playback operations when reading the main data, ensuring the reading of the table of contents data. In addition, there is an advantage that it is not necessary to perform an extra operation for detecting the disc diameter.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 2 spindle motor 3 motor servo circuit 4 servo constant setting means 9 sub code separation / Q code demodulation circuit 14 signal processing circuit 15 clock recovery circuit 16 system control circuit 18 track jump control means 19 TOC memory 20 TOC reading detection means 21 switching signal generation Means 22 Timer means 23 High speed detecting means 24 Disc discriminating means

Claims (1)

[Claims] 1. A disc is read by a pickup by rotating discs of large and small diameters having different diameters, and a rated speed of the disc is obtained by rotating each disc at a predetermined high speed higher than the rated speed. In a disc player capable of high-speed reading in addition to reading, switching signal generating means for generating a switching signal for selectively switching the reading speed of the disc between a rated speed and a high speed, and a spindle for rotating the disc. In addition to controlling the motor, the motor servo circuit is constructed so that the servo constants can be switched according to the large-diameter and small-diameter disks, and the rotation of the disk can be increased from the rated speed in response to the switching signal from the switching signal generating means. Rotation control means for controlling the motor servo circuit to switch to speed, and disk reading speed Starts timing when switching from rated speed to high speed, and measures the preset time according to the time required to start up the small diameter disk from rated speed to high speed, and the reading of the disk And a high speed detecting means for detecting that the high speed reading is performed by the high speed detecting means before the measurement of the set time by the timer means is completed. When detected, the servo constant of the motor servo circuit is set corresponding to the small-diameter disk, and on the other hand, the set time by the timer means before it is detected by the high speed detection means that high speed reading is performed. When the measurement of is completed, the servo constant of the motor servo circuit is set corresponding to the large-diameter disk. Player.