JPH087456A - Signal reproducing device - Google Patents

Abstract

PURPOSE:To improve signal reading performance and also to read a signal at high speed. CONSTITUTION:A CD-ROM 2 is rotated by a spindle motor 3 in a double speed mode. The signal is read by an optical head part 5 and stored in a memory part 8 through a digital signal processing part 6 and a CD-ROM decoder part 7. In the case the signal from the CD-ROM 2 can not be read by the head part 5, the rotation of the motor 3 is decelerated to set the mode to a standard speed mode and the signal is read. When the signal is read, reproducing speed is changed to the double speed mode again by judging based on idle time between a data read instruction and the next data read instruction from a host computer 20 that the memory part 8 fully stores the data. During a period when the reproducing speed is changed from the standard speed mode to the double speed mode, the data stored in the memory part 8 is supplied to the host computer 20. The data is supplied at high speed without waiting time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal reproducing apparatus suitable for reproducing a CD-ROM in which programs, data, video and audio data, etc. are recorded on a compact disc.

[0002]

2. Description of the Related Art Compact discs are generally known as CD software (hereinafter referred to as "CD-D") in which well-known audio signals are recorded.
In addition to "A"), CD software (hereinafter referred to as "CD-ROM") in which various information such as programs and data or video and audio data is recorded is known.

On this CD-ROM disc, data is collectively recorded in a certain minimum unit (hereinafter referred to as "block"), and the length of the block is CD-DA.
It is set to 1/75 seconds like the subcode length. Further, the read of the recorded data is performed by using the absolute address of the channel Q of the subcode as in the CD-DA.

The total amount of data recorded in one block is 44.1 × 10 ³ × since the sampling frequency is 44.1 kHz, the quantization number is 16 bits and the number of channels is 2.
16 × 2 × 1/75 = 18816 bits = 2352 bytes. The 2352-byte data has a structure as shown in FIG.

In FIG. 7, the sync area (12 bytes)
Is recorded with a synchronization pattern indicating division of blocks.
Absolute time and mode information are recorded in the header area (4 bytes). Information such as programs and data is recorded in the user data area. In the auxiliary data area, codes for error detection and correction are recorded to improve the level of the error correction function.

FIG. 7A shows a "mode 0" configuration, which is used for a dummy block in the lead-in and lead-out portions. In "mode 0", "0" data is recorded in the user data area. FIG. 7B shows the configuration of “mode 1”, which is used for recording data that requires reliability, such as computer data. FIGS. 7C and 7D show the configuration of “mode 2”, and the configuration of “mode 2” includes two types, “mode 2 form 1” shown in FIG. 7C and “mode 2 form 2” shown in FIG. 7D. For example, the configuration of “mode 2 form 1” is used for recording computer data and the like, and the configuration of “mode 2 form 2” is used for recording image data and the like, so that computer data and image data are stored. It can be handled in the same way as the data of "mode 2".

In addition, in the Photo-CD having the "mode 2" structure and additionally recordable later, the management information of the additional data is additionally recorded when additionally recording the data,
As shown in FIG. 8, a disc configuration is formed in which a plurality of pairs of management information and data are formed (hereinafter referred to as "multi-session"). In FIG. 8, data management information 52a and data 52b are recorded as the first recording on the inner circumference side of the recording area 51 of the disc 50. After that, the data management information 53a is recorded as the second recording on the outer peripheral side of the area recorded first.
And data 53b are recorded. In addition, 54 is a disk 5
A center hole portion for holding 0. Photo
In the o-CD, the maximum number of sessions is 25 because additional recording can be performed up to 25 times.

Next, a CD-ROM recorded in this way
FIG. 9 shows the configuration of a signal reproducing device for reproducing the.

In FIG. 9, 1 is a signal reproducing device,
The signal reproducing device 1 is connected to an external device such as the host computer 20 via the SCSI connector section 11. The operation of the signal reproducing device 1 is controlled by a command from the connected host computer 20.

When a command is supplied from the host computer 20 to the signal reproducing device 1, the command is sent to the SCSI connector unit 1.
1 and the SCSI terminator section 10 described later
It is supplied to the SI control unit 9. In the SCSI control unit 9, the command from the host computer 20 is processed and supplied to the system control unit 12. A control signal is supplied from the system control unit 12 to the servo control unit 4, the digital signal processing unit 6 and the like according to the supplied instruction. With this control signal, for example, a CD
-Reading of data from ROM2 is performed.

The CD-ROM 2 is rotated by a spindle motor 3 so that the linear velocity is constant. The rotation speed of the spindle motor 3 is controlled by the servo control unit 4. In addition, the servo controller 4 causes the CD-ROM
Focusing control and tracking control of the optical head unit 5 for reading the signal recorded in 2 are performed. The control operation of the servo control unit 4 is controlled by the digital signal processing unit 6 and the system control unit 12.

CD-read by the optical head unit 5
The signal of the ROM 2 is supplied to the digital signal processing unit 6. In the digital signal processing unit 6, after the data signal supplied from the optical head unit 5 is EFM demodulated, the data is arranged in the original order and error correction is performed. After that, when the data signal is a data signal similar to the audio signal of CD-DA (hereinafter referred to as “audio data signal”), the data signal is supplied to the D / A converter 15. Further, when the data signal is a data signal such as a computer program or computer data (hereinafter referred to as “computer data signal”), it is supplied to the CD-ROM decoder section 7.

In the CD-ROM decoder section 7, the computer data signals supplied from the digital signal processing section 6 are rearranged again, and error detection and correction are performed and output to the SCSI control section 9. In addition, CD
-The memory unit 8 is connected to the ROM decoder unit 7. The memory unit 8 will be described later.

The SCSI control unit 9 converts the supplied data signal into a data format of a SCSI interface and supplies it to an external device via the SCSI terminator 10 and the SCSI connector unit 11.

By the way, the host computer 20 is C
The data reading process is not always executed from the output of the command for starting the data reading of the D-ROM 2 to the end of the data reading, and the data reading process may be interrupted by, for example, an interrupt process. Even in this case, the data reading of the CD-ROM 2 is continued, and the computer data signal supplied from the digital signal processing unit 6 is temporarily stored in the memory unit 8 connected to the CD-ROM decoder unit 7. To be done. Therefore, even if the data reading process of the host computer 20 is started again, the data reading process is promptly performed by reading the data stored in the memory unit 8.

The audio data signal supplied from the digital signal processing unit 6 to the D / A converter 15 is a D / A
The analog audio signal is converted by the converter 15 and output from the audio output terminals 17L and 17R.

The system control unit 12 has a Bus
The y display unit 13 and the switch unit 14 are connected,
The Busy display unit 13 displays a CD-DA or CD-RO.
Busy display indicating that the M data is being read is performed. For example, a loading switch is provided in the switch unit 14, and by operating the switch unit 14, a loading operation for disc exchange or the like is performed.

The SCSI terminator section 10 is a termination circuit for terminating the signal lines of the devices at both ends of the signal line of the SCSI interface to which a plurality of devices are connected, with a predetermined resistance value. This SCSI terminator part 1
A terminator switch 18 whose one terminal is grounded is connected to 0, and the terminator switch 18 is manually operated to switch whether to terminate the signal line of the SCSI interface.

[0019]

By the way, the CD-RO
In addition to the standard speed mode, which is the same playback speed as the CD-DA, the playback operation of M is performed in the double speed mode, which is twice the standard speed, and the triple speed mode, which is three times the standard speed. Etc. are possible. Therefore, in order to read the signal recorded on the CD-ROM at a high speed, reproduction is performed in a mode faster than the standard speed mode, for example, a double speed mode.

When a reading error occurs during the reproducing operation in the double speed mode, the reproducing speed is changed to the standard speed mode and the reading operation is performed again in order to surely read the signal recorded in the CD-ROM. Be seen. However, even if reading is performed by the reading error generating section, the signal cannot be read at high speed unless the reproduction speed is changed to the double speed mode, resulting in a decrease in processing speed.

In view of this, the present invention provides a signal reproducing apparatus which improves signal reading performance and enables high-speed signal reading.

[0022]

According to a first aspect of the present invention, there is provided a signal reproducing apparatus, a drive control section for driving a recording medium in a plurality of driving speed modes to read a signal recorded on the recording medium, and a recording method. A signal processing unit that reads and processes a signal from a medium, and when a signal reading error of a recording medium signal occurs in the signal processing unit, the drive speed mode of the drive control unit is switched to a slow speed mode. is there.

According to another aspect of the signal reproducing apparatus of the present invention, when the drive speed mode of the drive control section is switched to the slow speed mode and the signal processing section can read the signal read error occurrence section. The drive speed mode of the drive control unit is switched to the high speed mode.

According to a third aspect of the present invention, there is provided a signal reproducing device which temporarily stores the signal processed by the signal processing part, and a signal which is read out from the signal stored in the signal storing part, processed, and then output. When the signal processing unit is capable of reading the portion in which the signal reading error has occurred by switching the drive speed mode of the drive control unit to the slow speed mode, the signal is stored in the signal storage unit. After the storage of the capacity, the drive speed mode of the drive control unit is switched to the high speed mode.

[0025]

In the signal reproducing apparatus according to the first aspect of the present invention, the drive speed mode of the drive control unit is switched to the slow speed mode when an error in reading the signal of the recording medium occurs in the signal processing unit. Therefore, the signal of the recording medium can be reliably read, so that the reading performance can be improved.

In the signal reproducing apparatus according to the second aspect of the present invention, when the drive speed mode of the drive control section is switched to the slow speed mode and the signal processing section can read the signal reading error generating section. The drive speed mode of the drive controller is switched to the high speed mode. Therefore, it is possible to read data at high speed even after a signal reading error occurs.

In the signal reproducing apparatus according to the third aspect of the present invention, the driving speed mode of the driving motion control section is switched to the slow speed mode, and the signal processing section can read the signal reading error generating section. At this time, after the signal of a predetermined capacity is stored in the signal storage unit, the drive speed mode of the drive control unit is switched to the high speed mode. For this reason,
For example, the drive control unit switches to a high speed mode when a signal is stored in the signal storage unit by a predetermined amount due to a vacant time between the data read command from the host computer and the next data read command. Since the signal stored in the signal storage unit is supplied to the host computer during the speed changing period, data can be supplied at high speed without waiting time, and a continuous good display screen is obtained in moving image reproduction and the like. It becomes possible.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the signal reproducing device according to the present invention will be described below with reference to FIG. FIG.
In FIG. 9, parts corresponding to those in FIG.

In FIG. 1, the sub-control unit 22 has an expanded function of the I / O port of the system control unit 12a and the like.
a, the servo control unit 4, the digital signal processing unit 6, and the like. A display control unit 23 is connected to the sub-control unit 22.

A switch section 24 and a display section 25 are connected to the display control section 23. The switch section 24 includes
A reproduction key, a pause key, a stop key, a skip key, a search key, and the like are provided so that the reproduction control of the CD-DA can be performed regardless of a command from the host computer 20 connected to the SCSI connector section 11. Therefore, by operating the key of the switch section 24, a key determination signal is supplied from the display control section 23 to the sub control section 22, and operation control according to the key operation is performed.

Further, a display data signal relating to an operation or the like is supplied from the sub-control unit 22 to the display control unit 23, and the operation or the like is displayed on the display unit 25.

The display section 25 is composed of, for example, an LCD display element, and has a display structure as shown in FIG.
In FIG. 2, an area a is an area for displaying the type of the disc, and for example, when a CD-ROM is reproduced, "CD
-ROM "is displayed. The area b is an area for displaying the termination state of the SCSI terminator unit 10. For example, when the SCSI terminator unit 10 is in the termination state, "TERM-ON" is displayed. Also, the region c
Is an area for displaying the operating state, such as a CD-R
In the case of OM, the SCSI interface ID number and P
The number of sessions on the photo-CD is displayed, and the CD-
The DA displays the song number, time, and the like. The display example of the area c in FIG. 2 shows that the ID number is 6, the mounted disc is Photo-CD, and the number of sessions is 5.

The display unit 25 is not limited to the LCD display element, and may be a display element such as a fluorescent display tube. Further, it goes without saying that the display configuration is not limited to the configuration shown in FIG.

The terminal of the terminator switch 18 connected to the SCSI terminator section 10 is connected to the sub-control section 22, and when the terminator switch 18 is operated, a switch signal indicating the operation state of the terminator switch 18 is sub-controlled. It is supplied to the system control unit 12a via the unit 22. Thereafter, a signal based on this switch signal is displayed on the display control unit 23.
Is supplied to the area b of the display unit 25 as described above.
The termination status of the CSI terminator unit 10 is displayed. Therefore, by checking the display of the display unit 25, the setting state of the terminator unit 10 can be easily grasped, and troubles due to a setting mistake at the termination of the signal line of the SCSI interface can be prevented.

In the signal reproducing apparatus configured as described above, when the task of reading the CD-ROM 2 in the double speed mode is executed by the system control unit 12a in accordance with the data reading command from the host computer 20, the signal is reproduced. The processing operation when the reading error occurs is shown in the flowchart of FIG.

In FIG. 3, the occurrence of a read error is determined in step ST1. When it is determined in step ST1 that a reading error has occurred, the process proceeds to step ST2.

In step ST2, it is determined whether the reading of the CD-ROM 2 has been repeated a prescribed number of times.
If the reading has not been repeated the specified number of times, the process proceeds to step ST3, the signal is read again at step ST3, and the process proceeds to step ST1 to determine whether a read error has occurred.

If it is determined in step ST2 that the reading has been repeated the specified number of times, the process proceeds to step ST4, and the standard speed mode change request flag is turned on.

If no reading error occurs in step ST1, the process proceeds to step ST5. Step ST
In 5, cache processing is performed in which the data signal supplied from the digital signal processing unit 6 to the CD-ROM decoder unit 7 is temporarily stored in the memory unit 8.

As described above, in the task of reading the CD-ROM 2, if the reading error occurs even after the reading is repeated a prescribed number of times and the change request flag to the standard speed mode is turned on, the system control unit 12a. Then, the reproduction speed changing process shown in the flowchart of FIG. 4 is performed.

In step ST10 in FIG. 4, it is determined whether or not the change request flag to the standard speed mode is on. When the change request flag to the standard speed mode is ON, the process proceeds to step ST11. In step ST11, the reproduction speed is changed from the double speed mode to the standard speed mode and the task of reading is performed, and the process proceeds to step ST12. In step ST10, if the change request flag to the standard speed mode is not turned on, the process proceeds to step ST12.

At step ST12, it is judged whether or not the data signal is stored in the memory section 8 by a predetermined capacity. For example, if the next data read command is not supplied after the processing for the data read command from the host computer 20 is completed or the data read command is temporarily interrupted and the data signal is fully stored in the memory 8, step ST13. Then, it is determined whether the operation is in the standard speed mode. Here, in the case of the operation in the standard speed mode, the process proceeds to step ST14 and is changed to the double speed mode again. If the data signal is not fully stored in step ST12,
When the operation is not in the standard speed mode at 13, the reproduction speed changing process ends without being changed to the double speed mode.

As described above, when the reproduction operation is performed in the double speed mode, C
When a reading error of the D-ROM 2 occurs, the reading is performed in the standard speed mode in which the reproduction speed is slow, so that the occurrence of the reading error can be prevented.
The signal recorded in can be reliably read.

Further, after the reading is performed in the standard speed mode in which the reproducing speed is slow, the reproducing speed is changed to the double speed mode again, so that the data can be read at high speed.

Further, when the data signal is fully stored in the memory portion 8 due to the idle time of the data read instruction and the next data read instruction, the mode is changed to the double speed mode again and the reading is performed. Computer 20
Even if the data read command from the memory is executed, the memory unit 8 is operated during the period of changing the reproduction speed from the standard speed mode to the double speed mode.
The stored data is supplied, and after the reproduction speed is changed, the reproduction is performed in the double speed mode. Therefore, data can be supplied to the host computer 20 at high speed without waiting time, and a continuous and good display screen can be obtained in, for example, moving image reproduction.

Note that the switching of the reproduction speed is not limited to the standard speed mode and the double speed mode. If the reproduction speed is switched including the triple speed mode, etc., the signal can be read at a higher speed and more reliably. You can

By the way, during the signal reading operation of the CD-ROM or the like mounted on the signal reproducing apparatus 1, the B indicator is displayed on the Busy display section 26 connected to the system control section 12a.
The busy display is made. The Busy display unit 26 is composed of, for example, two light emitting elements. One of the light emitting elements performs display (hereinafter referred to as “data Busy display”) according to the reading operation of the computer data signal, and the other light emitting element. Displayed according to the reading operation of the audio data signal on the device
That is done). Here, the display operation of the Busy display unit 26 is shown in the flowchart of FIG.

In FIG. 5, when a command is supplied from the host computer 20 to the signal reproducing apparatus 1 in step ST20, it is determined in step ST21 whether the command is a command for reading a computer data signal or a command for reading an audio data signal. To be done. If the instruction is to read a computer data signal, the process proceeds to step ST22, the busy display for data is started, and the process proceeds to step ST23. If the audio Busy display is already being performed while the audio data signal is being read in step ST22, the audio Busy display is stopped and then the data Busy display is performed. In step ST23, the supplied instruction is processed. After that, when the processing is completed, the process proceeds to step ST24, the busy display for data is completed, and the process proceeds to step ST27.

If it is determined in step ST21 that the command is not a command for reading a computer data signal, step S
The process proceeds to T25, the audio Busy display is started, and the process proceeds to step ST26. In step ST26, reading of the audio data signal is started from the designated position in accordance with the supplied instruction, and the process proceeds to step ST27.

In step ST27, it is returned to the host computer 20 that the reading of the computer data signal is completed or the reproduction of the audio data signal is started from the designated position.

Although not shown in the flow chart, even when the reading of the audio data signal is started by operating the switch section 25, the audio B
The busy display is performed. Also, the Busy display unit 26 has 2
Although it is assumed that the light-emitting device is configured by one light-emitting element, the Busy display unit 26 may be configured by a two-color LED or the like that can switch and emit two colors of light, and the Busy display unit 26 is not used and displayed on the display unit 25. As a matter of course, it can be inexpensively constructed.

In this way, the Busy display section 26 displays the Busy display showing the reading of the computer data signal and the Busy display showing the reading of the audio data signal in a divided manner, whichever data signal is being read. Can be easily grasped. Also, for example, when no sound is output, it is possible to easily determine whether the cause is the signal reproducing device or a device such as an amplifier connected to the signal reproducing device by checking the Busy display.

Next, the reading operation of the number of sessions of the Photo-CD having the multi-session disc structure will be described with reference to the flowchart of FIG.

In step ST30 in FIG. 6, Photo
When the o-CD is mounted on the signal reproducing device 1, step ST3
When the process proceeds to 1, it is determined in step ST31 whether the disc is a Photo-CD disc. If it is determined that the disc is a Photo-CD disc, the process proceeds to step ST32.

In step ST32, the count value of the counter for counting the number of sessions is set to 1, the process proceeds to step ST33, and the number of sessions is displayed on the display unit 25. The display of the number of sessions is displayed in the area c of the display unit 25. Then, the process goes to step ST34 to search for the next session.

In the session search of step ST34, the lead-out section is searched based on the management information, for example. When this session search is performed, the optical head unit 5
In step ST35, it is determined whether or not has entered the mirror surface of the outermost peripheral portion of the disc, or the tracking servo has deviated because no signal is recorded on the disc.

If the mirror surface is not entered or the tracking servo is not disengaged in step ST35, the process proceeds to step ST36 and 1 is added to the count value of the counter for counting the number of sessions. Then, it progresses to step ST33 and the number of sessions is displayed.

If it is not determined in step ST31 that the disc is a Photo-CD, and if the mirror surface is entered or the tracking servo is deviated in step ST35, the session number reading operation is terminated.

As described above, when reading a Photo-CD having a multi-session disc structure,
The number of sessions is displayed on the display unit 25.
It is possible to easily understand how much more pictures can be additionally recorded on the o-CD.

[0060]

According to the signal reproducing apparatus of the first aspect of the present invention, the drive speed mode of the drive control unit is switched to the slow speed mode when an error in reading the signal of the recording medium occurs in the signal processing unit. To be Therefore, the signal of the recording medium can be reliably read, and the reading performance can be improved.

According to the signal reproducing apparatus of the second aspect of the present invention, the drive speed mode of the drive control section is switched to the slow speed mode and the signal processing section can read the signal reading error generating section. At this time, the drive speed mode of the drive controller is switched to the high speed mode. For this reason,
Data can be read at high speed even after a signal reading error occurs.

According to the third aspect of the signal reproducing apparatus of the present invention, the drive speed control section switches the drive speed mode to the slow speed mode and the signal processing section can read the signal read error generating section. At this time, after the signal of a predetermined capacity is stored in the signal storage unit, the drive speed mode of the drive control unit is switched to the high speed mode. For this reason, for example, when the signal storage unit stores a signal of a predetermined capacity in the idle time between the data read command from the host computer and the next data read command, the drive control unit switches to the high speed mode. At the same time as switching, the signal stored in the signal storage unit is supplied to the host computer during the speed change period, so that data can be supplied at high speed without waiting time, and continuous and good display is possible in moving image reproduction and the like. You can get the screen.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a signal reproducing device according to the present invention.

FIG. 2 is a diagram showing a display example of a display unit 25.

FIG. 3 is a diagram showing a processing operation when a read error occurs.

FIG. 4 is a diagram showing a reproduction speed change processing operation.

FIG. 5 is a diagram showing a Busy display operation.

FIG. 6 is a diagram showing an operation of reading the number of sessions.

FIG. 7 is a diagram showing a data structure of a CD-ROM.

FIG. 8 is a diagram showing a configuration of Photo-CD.

FIG. 9 is a diagram showing a configuration of a conventional signal reproducing device.

[Explanation of symbols]

 1 signal reproducing device 2 CD-ROM 3 spindle motor 4 servo control unit 5 optical head unit 6 digital signal processing unit 7 CD-ROM decoder unit 8 memory unit 9 SCSI control unit 10 SCSI terminator unit 11 SCSI connector unit 12, 12a system control Part 13, 26 Busy display part 14, 24 Switch part 15 D / A converter 17L, 17R Audio output terminal 18 Terminator switch 20 Host computer 22 Sub-control part 23 Display control part 25 Display part

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G11B 20/18 F 8940-5D

Claims (3)

[Claims] 1. A drive control unit that drives a recording medium in a plurality of drive speed modes to read a signal recorded on the recording medium, and a signal processing unit that reads and processes the signal from the recording medium. A signal reproducing apparatus characterized in that, when an error in reading a signal from a recording medium occurs in the signal processing unit, the drive speed mode of the drive control unit is switched to a slow speed mode. 2. The drive speed of the drive control unit when the drive speed mode of the drive control unit is switched to a slow speed mode so that the signal processing unit can read the portion in which the signal reading error occurs. 2. The signal reproducing apparatus according to claim 1, wherein the mode is switched to a high speed mode. 3. A drive unit comprising: a signal storage unit for temporarily storing a signal processed by the signal processing unit; and a signal output unit for reading out a signal stored in the signal storage unit, processing the signal, and outputting the processed signal. When the drive speed mode of the control section is switched to the slow speed mode and the signal processing section can read the section in which the signal reading error occurs, the signal is stored in the signal storage section in a predetermined capacity. The signal reproducing apparatus according to claim 1, wherein the drive speed mode of the drive control unit is thereafter switched to a high speed mode.