JPH08167229A - Disk player - Google Patents

Abstract

PURPOSE: To prevent the generation of a sound interruption by previously discriminating whether the data of a required region is normally read or not in accordance with the residual quantity of the information of a memory and controlling retry reading out in the next writing period in accordance with the result of the discrimination. CONSTITUTION: The writing and reading out of the memory 6 are controlled by a system controller 9 and a memory controller 5. Whether the data is normally read or not is discriminated by reading the data from the address to be read next in a data writing disable period after the state that the residual quantity of the data of the memory 6 is above the first reference value until the residual quantity falls just before the second reference value smaller than this reference value. Writing is executed after retry reading out in the writable period at the time when the residual data of the memory 6 falls down to the second reference value or below. This reading out is controlled in accordance with the result of the discrimination. The occurrence of the sound interruption is prevented without the useless consumption of the time in processing to the reading disable section and without the absence of the data in the memory 6.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a mini disc (M
D), a compact disc (CD), and other disc players for reproducing (playing) discs.

[0002]

2. Description of the Related Art In a conventional mini-disc player, in the case of a disc on which digital audio data is recorded, the data read by a pickup from the disc at the time of reproduction is temporarily written in a memory after passing through an EFM decoder. The data written in this memory is read at a speed lower than the writing speed in the writing order. The read data is the audio compression decoder and D
It is output as an analog audio signal after passing through the / A converter. In a disc such as a mini disc, an address is attached to the header portion of each data block in units of, for example, 2 Kbytes, and the data is read out for each address according to the address. Further, the read data is erased in the memory.

If the data cannot be read from the disk or if the read data is abnormal, another read operation, that is, a retry operation is performed from the address where the correct data on the disk could not be read. If the correct data is not written in the memory, this retry operation is continued until the remaining amount of the data already written in the memory falls below a certain value. However, when the remaining amount of data in the memory becomes equal to or less than a certain value, the retry operation is stopped, the address is changed to the next data readable address on the disk, and a new data reading operation is performed.

FIG. 1 shows the reading operation as a control flow chart of a system controller in the mini disc player. That is, the system controller issues an instruction to read the data at the address N of the disk (step S101), and determines whether or not the data reading operation is normally performed (step S102). EFM above
In the decoder, CIRC (Cross
s Interleave Reed-Solomon Code) is used to detect error data, and an error signal is generated when error data is detected. Therefore, the system controller responds to the error signal and the read data is normal. It is possible to determine whether or not. If the read data is normal, the writing of the read data to the memory is instructed (step S103). Then, it is determined whether or not the program to be reproduced is completed (step S108). When the program to be reproduced is completed, this routine is completed.
However, if the program to be reproduced is not yet finished, it is determined whether or not the remaining amount of data in the memory is equal to or larger than the first reference value (step S104). If the remaining amount of data in the memory is less than the first reference value, 1 is added to the disk address N to make it a new address N (step S105), and then the process returns to step S101.

On the other hand, when the remaining amount of data in the memory is equal to or larger than the first reference value, the reading operation is temporarily put into a pause state (step S106). Since the amount of data in the memory is reduced by reading the data from the memory in the paused state, it is determined whether or not the remaining amount of data in the memory is equal to or less than the second reference value after the execution of step S106 (step S1).
07). When the remaining amount of data in the memory is larger than the second reference value, the execution of step S107 is repeated and the data is read from the memory, so the remaining amount of data in the memory gradually decreases. When it is determined that the remaining amount of data in the memory has dropped below the second reference value, 1 is added to the address N in step S105 and the new address N
After that, the process returns to step S101.

When it is determined in step S102 that the data reading operation is not normally performed, it is determined whether or not the remaining amount of data in the memory is equal to or less than the third reference value which is smaller than the second reference value. (Step S109). In the retry operation, the search operation is performed so that the pickup returns to the head of the address position where the data could not be read normally, and the read operation is restarted for that address. Therefore, the remaining amount of data in the memory is the third
If it is larger than the reference value, for example, when it is first determined that the data reading operation is not normally performed on the current address N, the pickup is made to search the address N of the disc (step S110), and then the address N is read. By returning to step S101 in order to read the data, the retry operation is performed. Since the data cannot be read normally, the remaining amount of data in the memory is the third
When the value is lower than the reference value, 1 is added to the address N to set the new address N in order to move to the data reading of the next address (step S111), and then the process returns to step S101.

Next, an example of the operation of reading data from the disk by the read control operation will be described with reference to FIG.
The addresses S0, S1, S2, ...
The data is recorded in the order of, and here, the address S4
Data cannot be read for. FIG. 2 (A)
Indicates the flow of read addresses when playing a disc,
FIG. 2B shows a change in operation mode, where
A indicates a reading operation, B indicates a pause operation, and C indicates a search operation. FIG. 2C shows the time when the error signal is generated because the data cannot be read. FIG. 2D shows the time when writing to the memory is performed. FIG. 2E shows the remaining amount of data in the memory.

The flow of the operation shown in FIG. 2 will be described. First, since the data is read from the memory and output during the pause operation B, the remaining amount of data in the memory at time t ₁ . Becomes lower than the second reference value, the period during which the writable signal is generated, that is, the writable period is entered, the operation mode shifts to the data reading operation A from the disk, and the respective data at the addresses S0, S1, S2 are read in order and the memory Since the read data is written in, the remaining amount of data in the memory increases. When the remaining amount of data in the memory increases from the first reference value at time t ₂ due to the writing of the data of the address S2, the write disable signal generation period, that is, the write disable period is entered, and the operation mode is set to the pause operation B again. Becomes Since data is read from the memory and output during the pause operation, the remaining amount of data in the memory gradually decreases. When the remaining amount of data in the memory falls below the second reference value at time t ₃ , the operation mode shifts to the data reading operation A from the disk and addresses S3, S4, ... Are read in this order. However, at time t ₄
Since the data reading operation for the address S4 is not correctly performed at, an error signal is generated. Therefore, time t
Reading position of the pickup by the search operation C from ₅ returns to the start position of the address S4, the data read operation A for the address S4 at time t ₆ is started. Thus the search operation read data to address S4 are repeated and the data remaining amount falls below the third reference value, the reading position of the search operation C in the pickup from time t ₇ is moved to the start position of the address S5 Of.
This is because when the retry operation is repeated, the remaining amount of data in the memory greatly falls below the second reference value as shown in FIG. 2 (E), and when the retry operation is continued, the remaining amount of data in the memory disappears. Therefore, the reading of data for the address S4 is abandoned and the operation for reading the next address S5 is started. Address S5 followed by addresses S6, S
7 ... As the reading operation shifts, the remaining amount of data in the memory gradually increases.

[0009]

However, in such a conventional mini disk player, the remaining amount of data in the memory becomes small during the retry operation, which may cause a read operation such as vibration at the time. If this occurs, there is a problem in that the data at the readable address cannot be actually read until the data in the memory is exhausted, and a sound break occurs, making it difficult to hear. Further, this is not limited to a mini disc player, but other conventional disc players such as a compact disc player have a memory for temporarily writing the data read by the pickup from the disc at the time of reproduction,
The same problem also occurs in a player having a configuration that performs a retry operation when the reading is defective.

SUMMARY OF THE INVENTION An object of the present invention is to provide a disc player capable of preventing the occurrence of sound interruption due to the loss of data in the memory due to the retry operation for reading data.

[0011]

DISCLOSURE OF THE INVENTION A disk player of the present invention detects a reading means for reading data from a disk on which data is recorded, a memory for writing / reading data, and a remaining amount of data in the memory. Means for determining whether the memory is in a writable period or a writable period of data based on the remaining amount of data in the memory; and writing data to the memory in the writable period. And a memory control means for reading data from the memory at a speed lower than the writing speed, the reading being for controlling the reading means so as to read new data from the disk in the unwritable period. A control means and a second means for determining whether or not the data read by the reading means during the unwritable period is normal data.
Discriminating means, and according to the discrimination result of the second discriminating means,
The operation of the reading means or the memory control means is changed during the subsequent writable period.

[0012]

According to the present invention, the memory remaining from the time when the remaining amount of data in the memory becomes, for example, the first reference value or more until just before the remaining amount of data decreases below the second reference value which is smaller than the first reference value. In the period in which the data cannot be written to, the data is read from the data position of the address to be read next by the reading means in advance to determine whether or not the data can be normally read, and then the remaining amount of data is the second When it becomes less than the reference value and the data writable period in the memory comes, the operation of the reading unit or the memory control unit is changed according to the determination result.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the mini disc player shown in FIG. 3, the data recorded on the disc 1 is read by the optical pickup 2, and the read signal is supplied to the EFM decoder 4 via the RF amplifier 3. The EFM decoder 4 error-corrects the data of the read signal by the CIRC method, demodulates it by EFM, and supplies it to the memory controller 5. The memory controller 5 is a RAM (Randam Access Me
control the writing and reading of data to and from the memory 6. The memory 6 has, for example, a capacity of 4 Mbit, a writing speed is 1.4 Mbit / sec, and a reading speed is lower than the writing speed.
It is performed at a rate of Mbit / sec. The memory controller 5 writes data to the memory 6 in accordance with an instruction from the system controller 9 described later, and performs a data read operation as long as data exists in the memory 6 during disk reproduction. The read data is erased from the memory 6. The data read from the memory controller 5 is supplied to the audio compression decoder 7. The audio compression decoder 7 demodulates a digital audio signal compressed and recorded by an audio compression technique called ATRAC (Adaptive TRansform Acoustic Coding). The digital audio signal obtained by the voice compression decoder 7 is D / A.
A (digital / analog) converter 8 converts the analog audio signal and outputs the analog audio signal.

The EFM decoder 4 and the memory controller 5 are controlled by a system controller 9 composed of a microcomputer. The system controller 9 also controls the servo circuit 10. The servo circuit 10 performs each servo control of spindle servo, tracking servo, focus servo, and carriage servo, extracts a servo signal from the read signal in the RF amplifier 3, and as a result, the read position and focusing of the pickup 2 and the spindle motor 11. Control the rotation speed. The spindle motor 11 is a motor for driving the disk 1 to rotate.

Next, the reading operation from the disc 1 at the time of reproduction in the mini disc player will be described. As shown in FIGS. 4 and 5, the system controller 9 determines whether or not the address N is included in the NG address data before the data reading operation of the address N of the disk 1 is started (step S121). The NG address data is data indicating an unreadable address set in steps S133 and S138 described later. If the address N is not included in the NG address data, the data reading operation for the address N is instructed (step S
122), and it is determined whether or not the data reading operation is normally performed (step 123). When the data reading operation is normally performed, the writing of the read data to the memory 6 is instructed (step S124), and it is determined whether or not the program to be reproduced is completed (step S135). When the program to be reproduced is completed, this routine is completed. On the other hand, if the program to be reproduced has not ended, it is determined whether or not the remaining amount of data in the memory 6 is the first reference value or more (step S125). In response to an instruction to write read data to the memory 6, the memory controller 5
Writes the read data obtained via the EFM decoder 4 in the memory 6. When the remaining amount of data in the memory 6 is smaller than the first reference value, 1 is added to the address N of the disk to make it a new address N (step S12).
6). The operations of steps S122 to S126 are the same as steps S101 to S105 shown in FIG. After execution of step S126, the process proceeds to step S121, and it is determined whether or not the new address N is included in the NG address data. If the address N is included in the NG address data in step S121, the process proceeds to step S126 to obtain a new address N. If the new address N is not included in the NG address data, the process returns to step S122.

On the other hand, when the remaining amount of data in the memory is equal to or larger than the first reference value, the address M is set as N + 1 (step 127), and the reading operation of the data at the address M of the disk 1 is instructed (step S128). . It is determined whether the data reading operation has been normally performed (step 129). If the data reading operation is performed normally,
It is determined whether the remaining amount of data in the memory is less than or equal to the second reference value (step S130). When the remaining data amount of the memory is larger than the second reference value, 1 is added to the address M to set it as a new address M (step S131), and the process returns to step S128 to read the next address. If the data reading operation is not normally performed, it is determined whether or not a retry operation has been performed a predetermined number of times (step S132). When the retry operation is not performed a predetermined number of times, for example, when it is first determined that the data reading operation is not normally performed on the current address M, the pickup is made to search the address M of the disc (step S134), and thereafter , The retry operation is performed by returning to step S128 to read the data at the address M. When the data cannot be read normally and the retry operation is performed a predetermined number of times, the address M is stored in the memory (not shown) in the system controller 9 as NG address data (step S133). After that, the process proceeds to step S130 to determine whether the remaining amount of data in the memory is less than or equal to the second reference value.

When it is determined in step S130 that the remaining amount of data in the memory has dropped below the second reference value, 1 is added to the address N to make it a new address N in step S126, and then step S121. Return to. If it is determined in step S123 that the data reading operation is not normally performed even though the current address N is not included in the NG address data,
It is determined whether the remaining amount of data in the memory 6 is equal to or less than the third reference value (step S136). When the remaining amount of data in the memory 6 is larger than the third reference value, the pickup 2 is searched for the address N of the disc (step S13).
7) After that, the retry operation is performed by returning to step S122 to read the data of the address N. When the data cannot be read normally and the remaining amount of data in the memory 6 drops below the third reference value, the address N is stored as NG address data (step S138) and the data of the next address is read. In order to shift, 1 is added to the address N to make it a new address N (step S139), and then step S1
Return to 21.

Next, an example of the operation of reading data from the disk by the read control operation will be described with reference to FIG.
Here, as in the case described with reference to FIG.
Data is recorded on the top in the order of addresses S0, S1, S2, ..., It is impossible to read the data for the address S4. First, when data is read from the memory 6 and output during the pause operation B, and the remaining amount of data in the memory 6 falls below the second reference value at the time point t ₁ , the operation mode is the disk 1 The data read operation A is started and the data at the addresses S0, S1 and S2 are sequentially read, and the read data is written to the memory 6 by the generation of the write command signal shown in FIG. The remaining amount of data inside will increase. Address S2
When it is determined that the remaining amount of data in the memory 6 has increased from the first reference value at the time t ₂ due to the writing of the data of No. 6, the data writing to the memory 6 is not performed, but the operation mode is the read operation. It will remain A. By this reading operation A, first, data reading for the address S3 is performed.
When it is confirmed that read data normally the address S3 by nonoccurrence of an error signal, from the time t ₃ read data for the address S4 is started. However, since the data reading operation for the address S4 is not normally performed, an error signal is generated as shown in FIG. 6 (C). Therefore, the search position C of the pickup 2 is returned to the start position of the address S4 by the search operation C from the time point t _4, and the data read operation A for the address S4 is started at the time point t ₅ . In this way, the data reading to the address S4 is repeated by the search operation C, and when the number of retry readings reaches a predetermined number while the data reading is abnormal, the above step S135 is executed and the address S4 is stored as NG address data. It

On the other hand, since data is being read from the memory 6 even during the retry operation, at the time point t _{6 in} FIG.
As shown in (E), the remaining amount of data in the memory 6 reaches the second reference value. Correspondingly data at the address position S3 are searched, the reading operation A of the data at time t ₇ is started. At this time, since a write command signal is generated as shown in FIG. 6D, the read data is written in the memory 6. At time t ₈ after the data reading operation of the address S3, the address S4 to be read next is NG.
Since it is determined whether the address S4 is included in the address data and it is determined that the address S4 is included in the NG address data, the data reading operation of the address S4 is ignored.
Further, the search operation C is performed toward the data position of the next address S5. Address S from the subsequent time t ₉
.., S6, S7 ... Each data is sequentially read and the read data is written in the memory 6, so that the remaining amount of data in the memory 6 gradually increases. As a result, data is read from the disk 1 in the address order shown in FIG. 6A, and the operation mode changes as shown in FIG. 6B. In FIG. 6B, D indicates a pause operation.

FIG. 7 partially shows another control operation of the system controller 9 in the player of FIG. 3 as another embodiment of the present invention. The control operation of FIG. 7 follows the control operation part of FIG. In the control operation of FIG. 7, the same parts as the control operation shown in FIG. 4 are denoted by the same reference numerals, and the address N is included in the NG address data before the data read operation of the address N of the disk 1 is started. No determination is made as to whether or not it is. Therefore, when the data reading operation is first instructed for the address N in step S122 and it is determined in step S123 that the data reading operation is not normally performed, it is determined whether the address N is included in the NG address data. It is determined whether or not (step S140). If the address N is not included in the NG address data, the process proceeds to step S136, and it is determined whether or not the retry operation is performed until the remaining amount of data in the memory 6 becomes the third reference value or less. On the other hand, if the address N is included in the NG address data, the process proceeds to step S124 to write the abnormal read data in the memory 6. Further, even after the address N is stored as NG address data in step S138, the process immediately proceeds to step S124 to write the abnormal read data in the memory 6. Other operations are similar to those shown in FIG.

During the control operation of FIG. 7, the system controller 9 stores the read timing from the memory 6 as shown in FIG.
It is determined whether or not the address is included in the address data (step S141). If it is the timing to read the data of the address other than the address included in the NG address data, the read enable signal is generated to the memory controller 5 (step S142). However,
If it is the timing to read the data of the address included in the NG address data, the read inhibit signal is generated to the memory controller 5 (step S143).

FIG. 9 shows an example of the operation of reading data from the disk by the read control operation shown in FIGS. 7 and 8. As in the case described with reference to FIG. 2, data is recorded on the disc in the order of addresses S0, S1, S2, ..., It becomes impossible to read the data at the address S4. The operation up to time t ₈ is similar to that of FIG. 6, and after the data reading operation of the address S3, the data reading operation A of the addresses S4, S5, ... Is continuously performed.
The read data for the address S4 is abnormal data, but is written in the memory 6 as it is. However,
Since the address S4 is stored as NG address data, a read inhibit signal is supplied from the system controller 9 to the memory controller 5 at the time of reading data from the memory 6 for the address S4. It is not read, it is simply erased.

The data for the address S4 may be read from the memory 6 and the output of the read data may be prohibited by the mute circuit. FIG. 10 partially shows still another control operation of the system controller 9 in the player of FIG. 3 as another embodiment of the present invention. The control operation of FIG. 10 follows the control operation part of FIG. In the control operation of FIG. 10, the same parts as those of the control operation shown in FIG. 4 or FIG. 7 are denoted by the same reference numerals, and similarly to FIG. Then, when it is determined in step S123 that the data reading operation is not normally performed, it is determined whether or not the address N is included in the NG address data (step S140). If the address N is not included in the NG address data, the process proceeds to step S136, and it is determined whether or not the retry operation is performed until the remaining amount of data in the memory 6 becomes the third reference value or less. On the other hand, if the address N is included in the NG address data, the process proceeds to step S125 to prohibit writing to the memory 6. Other operations are similar to those shown in FIG.

FIG. 11 shows an operation example of reading data from the disk by the read control operation shown in FIG.
As in the case described with reference to FIG. 2, data is recorded on the disc in the order of addresses S0, S1, S2, ..., It becomes impossible to read the data at the address S4. The operation up to time t ₈ is similar to that of FIG. 6, and after the data reading operation of the address S3, the operation of the address S continues.
Data reading operation A of 4, S5, ... Is performed. Since the read data for the address S4 is abnormal data, even if it is read as abnormal data, it is not written in the memory 6.

In each of the above-mentioned embodiments, the remaining amount of data in the memory 6 is obtained, for example, from the difference between the read address of the disk and the read address of the memory 6. In each embodiment, the generation period of the memory write command signal is a data writable period in the memory, and the non-generation period is a writable period. Further, in each of the above-described embodiments, a player for reproducing a mini disk is shown as the disk player, but a player for reproducing another disk such as a compact disk, and the data read by the pickup from the disk at the time of reproduction is stored in the memory. The present invention can be applied as long as the data is written once in, read out, and output.

[0026]

According to the disc player of the present invention,
For example, in the period in which data cannot be written to the memory until the remaining amount of data in the memory becomes equal to or larger than the first reference value and immediately before the remaining amount of data decreases to the second reference value that is smaller than the first reference value. Data is read in advance from the data position of the address to be read by the reading means to determine whether or not the data can be read normally, and then the remaining amount of data falls below the second reference value to the memory. When the data writable period is reached, the operation of the reading unit or the memory control unit is changed according to the determination result, so that it is wasteful at an address where the data cannot be normally read during the data writable period. Time is prevented from being spent. Therefore, the data in the memory is not lost, and it is possible to prevent the sound interruption.

[Brief description of drawings]

FIG. 1 is a flowchart of a conventional data reading control operation.

FIG. 2 is a diagram showing an example of a control operation of FIG.

FIG. 3 is a block diagram showing an embodiment of the present invention.

4 is a flowchart of a data reading control operation executed by a system controller in the player of FIG.

FIG. 5 is a flowchart showing a continuation part of the data reading control operation of FIG.

6 is a diagram showing an example of the control operation of FIGS. 4 and 5. FIG.

7 is a flow chart of a data read control operation executed by a system controller in the player of FIG. 3 shown as another embodiment.

FIG. 8 is a flowchart showing an interrupt operation in the data read control operation of FIG.

9 is a diagram showing an example of the control operation of FIGS. 7 and 8. FIG.

10 is a flowchart of a data read control operation executed by a system controller in the player shown in FIG. 3 as another embodiment.

11 is a diagram showing an example of the control operation of FIG.

[Explanation of symbols for main parts]

 1 disk 2 pickup 4 EFM decoder 5 memory controller 6 memory 7 audio compression decoder 9 system controller

Claims (4)

[Claims] 1. A reading unit for reading the data from a disc on which data is recorded, a memory in which the data can be written and read, a unit for detecting the remaining amount of data in the memory, and data in the memory. First determining means for determining whether the memory is in a writable period or a writable period of data based on the remaining amount; and writing data to the memory in the writable period. A disc player having memory control means for reading data from the memory at a speed lower than a writing speed, the reading being for controlling the reading means so as to read new data from the disc in the write-disabled period. A control means and a second determination for determining whether or not the data read by the reading means during the unwritable period is normal data And a means for changing the operation of the reading means or the memory control means during the subsequent writable period according to the determination result of the second determining means. 2. The reading control means gives an instruction to the reading means during the writable period to prohibit reading of data for an address which the second judging means has determined not to read normally. The disc player according to claim 1. 3. The disc player according to claim 1, wherein the memory control means prohibits reading from the memory of data about an address determined by the second determination means to be not normally read. 4. The memory control means prohibits writing to the memory of data read by the reading means during the writable period with respect to an address determined by the second determining means not to be normally read. The disc player according to claim 1, wherein