JP3846299B2 - Optical disc recording / reproducing apparatus and reproducing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc recording / reproducing apparatus and a data reproducing method capable of speeding up data reading when switching from low-speed recording or low-speed reproduction to high-speed reproduction.
[0002]
[Prior art]
In recent years, there has been a strong demand for speeding up data reading of phase change type optical disks (hereinafter referred to as optical disks), and in order to shorten the data reading time, the spindle motor is rotated at high speed and CAV (Constant Angular Velocity) technology is used. It is used to read data with the spindle rotation speed constant, thereby realizing high-speed data reproduction. However, on the other hand, the ATIP (Absolute Time In PreGroove) read speed and recording speed written in advance in the optical disk manufacturing process to specify the current position at the time of data writing depend on the characteristics of the optical disk, peripheral devices, and Due to the performance limit of the optical components of the optical pickup module, the speed is lower than the data reproduction speed when reading data. For this reason, in order to perform data reading from data writing or data reading at a high speed from a reproducing speed for reading data at a low speed, data reproduction using the CAV technique is performed as the spindle rotation speed increases.
[0003]
A conventional optical disk recording / reproducing apparatus and its reproducing method will be described below with reference to FIGS. FIG. 6 is a block diagram showing a configuration of a conventional optical disc recording / reproducing apparatus, and FIG. 7 is a flowchart showing a reproduction speed switching sequence of the optical disc recording / reproducing apparatus of FIG. Reference numeral 1 denotes an optical disk, 2 a spindle motor for rotating the optical disk, and 3 a spindle motor driver for driving the spindle motor 2. 4 is a pickup unit for emitting a laser diode, 5 is an actuator driver for driving the pickup unit 4, 6 is a feed motor for moving the pickup unit 4 to an arbitrary position, and 7 is a feed motor for driving the feed motor 6. A driver 8 is an LD driver that supplies a driving current to the laser diode of the pickup unit 4. Reference numeral 9 denotes a read amplifier for amplifying the RF signal obtained by the pickup unit 4, and 10 denotes a CD servo processor that controls the feed motor 6, the spindle motor driver 3, and the actuator driver 5 based on each signal. 11 is a CD encoder that performs laser pulse control for recording data, 12 is an ATIP detector that extracts ATIP from the output signal from the read amplifier 9, and 15 is data obtained from the RF signal from the read amplifier 9, and the CD servo processor 10 This is a CD-ROM decoder for decoding via the CD. Reference numeral 14 denotes a buffer memory for storing data decoded by the CD-ROM decoder 15, and reference numeral 13 denotes a DAC (DA converter) for the CPU 16 described later to set laser power to the LD driver 8.
[0004]
When the CPU 16 requests the CD servo processor 10 to switch to the spindle rotation speed via the bus 19 described later, the CD servo processor 10 changes the PWM output level to the spindle motor driver 3, and the spindle motor driver 3. Changes the rotational speed of the spindle motor 2 in accordance with the input PWM output level. The CD servo processor 10 acquires the actual data reproduction speed based on the RF signal from the read amplifier 9 and controls the PWM output to the spindle motor driver 3 so as to achieve the target data reading speed. The ratio of the actual data reproduction speed to the target data reading reproduction speed (hereinafter, reproduction speed ratio) can be obtained, and the CPU 16 can acquire the reproduction speed ratio through the bus 19. The CPU 16 determines that the optical disk has reached the target playback speed when the playback speed ratio reaches 100%, sets the read power for reading to the DAC 13, and performs data read (playback operation). Reference numeral 16 denotes a CPU for performing logical judgment and calculation, and 17 is a read only memory (hereinafter referred to as ROM), which is a program storage area in which a control program according to the flowchart shown in FIG. 7 and a control program for an optical disc recording / reproducing apparatus are stored. have. A main memory 18 is used as a storage area necessary for recording control and data reproduction control. 19 is a bus.
[0005]
[Problems to be solved by the invention]
In the conventional optical disc recording / reproducing apparatus described above, when switching from a low-speed recording speed during data writing or a low-speed data reading reproduction speed to a high-speed data reading reproduction speed, Therefore, it is necessary to temporarily stop the data reading until the target reproduction speed is reached, and to increase the spindle rotation speed before performing the data reading. In particular, when a spindle motor with a small torque is used, since it takes time until data can be read out, the start of data reading is delayed and the performance is very poor.
[0006]
Furthermore, when data in the self-disc of the optical disc (data to be read) is copied to another area (data recording area) in the self-disc as in the packet write method, a plurality of data reading and data recording are alternately performed. In the case of repeated times, the longer the time until the start of data reading, the lower the performance of the entire optical disc apparatus.
[0007]
For this reason, it is conceivable to use a method called variable speed reproduction that can start reading data in parallel with switching of the reproduction speed, and to read data from the optical disk even if the target data reproduction speed is not reached. However, it is difficult to set the read area laser power irradiated per unit time and unit time to each layer of the optical disk. Therefore, in the conventional optical disc recording / reproducing apparatus, when the optical disc data reading is performed by switching from the low recording speed at the end of data writing to the optical disc to the high data reproducing rate for reading data, the target data reproduction is performed. When the target data reproduction speed is reached, data read is started after the read laser power corresponding to the data reproduction speed is set.
[0008]
Therefore, based on FIG. 7, a description will be given of a case where optical disk data is read by switching from a low recording speed at the end of data writing to a high data reproducing speed for data reading in the conventional optical disk recording / reproducing apparatus. do. The calculation according to the flowchart of FIG. 7 is executed by the control program stored in the ROM 17 and the CPU 16.
[0009]
In S1, playback speed switching for changing to the target data playback speed is started. Until the playback speed reaches the target data playback speed, the laser power is maintained at the reference laser power to suppress physical changes in the optical disk layer. For this reason, the data reading is temporarily stopped in S2.
[0010]
In S3, the reproduction speed ratio is acquired from the CD servo processor 10 and set to the variable R. In S4, the variable R is compared with 100%. If the variable R is less than 100%, the reproduction speed ratio is acquired again in S3, set in the variable R, and S4 is repeated. If the variable R is 100% or more, the read laser power corresponding to the target data reproduction speed is set in the DAC 13 in S5, the data reading is resumed in S6, and the reproduction speed switching is completed in S7.
[0011]
FIG. 8 is a diagram showing the relationship between the reproduction speed and the laser power of a conventional optical disk recording / reproduction apparatus. The reference laser power is set for the laser power from the start of playback speed switching to the end of playback speed switching (while playback speed switching is in progress) before switching the playback speed, and the target data playback speed laser power is set after switching the playback speed. It shows that. In addition, there is a time zone during which data cannot be read from the start of playback speed switching to the end of playback switching (while switching playback speed).
[0012]
An object of the present invention is to solve the above-described drawbacks, and to provide an optical disc recording / reproducing apparatus capable of reducing the time required for data reading and suppressing physical destruction of each layer of the optical disc.
[0013]
Another object of the present invention is to provide a reproducing method for an optical disc recording / reproducing apparatus that can reduce the time required for data reading and suppress physical destruction of each layer of the optical disc.
[0014]
[Means for Solving the Problems]
The optical disk recording / reproducing apparatus of the present invention switches from a low recording speed during recording to a high data reproducing speed during reproduction, or from a low data reproducing speed during reproduction to a high data reproducing speed. The control means selects the laser power setting table based on the target data reproduction speed, sets the laser power corresponding to the reproduction speed ratio from the laser power setting table, and sets the target and The laser power is increased stepwise until the data reproduction speed is reached, and data is read without interruption.
[0015]
Thereby, the time required for data reading can be shortened, and physical destruction of each layer of the optical disk can be suppressed.
[0016]
The reproducing method of the optical disk recording / reproducing apparatus of the present invention includes a plurality of laser powers in which a plurality of reproduction speed ratios representing a ratio between an actual reproduction speed and a target reproduction speed and the corresponding laser power are related to the target reproduction speed. A setting table is provided, and the laser power is increased step by step in a reproduction speed ratio unit until the target reproduction speed is reached based on the laser power setting table, and data is read without interruption. To do.
[0017]
Thereby, the time required for data reading can be shortened, and physical destruction of each layer of the optical disk can be suppressed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is based on a pickup unit for recording / reproducing data on / from a phase change optical disc, a spindle motor driver for controlling the rotation speed of the spindle, and an RF signal obtained from the pickup unit. The number of rotations of the spindle is detected, the actual playback speed is obtained, servo control is performed on the spindle motor driver from the difference from the target playback speed, and the ratio between the actual playback speed and the target playback speed is calculated. Servo control calculation means for calculating the playback speed ratio, control means for controlling the laser driver to control the laser light emission amount of the pickup unit during recording and playback, a control program for causing the control means to function, and the playback speed ratio Means for storing a plurality of laser power setting tables for setting laser power corresponding to An optical disk recording / playback device equipped with a low-speed recording speed during recording to a high-speed playback speed, or switching from a low-speed playback speed to a high-speed playback speed. The control means selects the laser power setting table based on the target reproduction speed, sets the laser power according to the reproduction speed ratio from the laser power setting table, and sets the target reproduction speed. Since the optical disk recording / reproducing apparatus is characterized in that the laser power is increased stepwise until data is read and data is read without interruption, the laser power is increased stepwise while suppressing physical destruction of each layer of the optical disk. Since the data reading is performed without interruption, the data reading can be speeded up.
[0019]
The invention according to claim 2 of the present invention is a playback method of an optical disc recording / playback apparatus that switches from a low-speed recording operation or a low-speed playback operation to a high-speed playback operation, and the actual playback speed and target A plurality of reproduction speed ratios representing the reproduction speed ratio and a plurality of laser power setting tables in which the corresponding laser power is related to the target reproduction speed are provided, and a target is set based on the laser power setting table. The data reproduction method of the optical disk recording / reproducing apparatus is characterized in that the laser power is increased stepwise in units of a reproduction speed ratio until the reproduction speed is reached, and data is read without interruption. The data can be read without interrupting the data reading while suppressing the mechanical destruction, and the reproduction operation can be speeded up.
[0020]
(Embodiment 1)
Hereinafter, an optical disk recording / reproducing apparatus and a reproducing method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical disk recording / reproducing apparatus according to Embodiment 1 of the present invention. The configuration of the optical disc recording / reproducing apparatus according to Embodiment 1 of the present invention is basically the same as that of the conventional optical disc recording / reproducing apparatus shown in FIG.
[0021]
In FIG. 1, 1 is an optical disk, 2 is a spindle motor for rotating the optical disk, 3 is a spindle motor driver for driving the spindle motor 2, 4 is a pickup unit for emitting a laser diode, and 5 is a pickup unit 4. 6 is a feed motor that moves the pickup unit 4 to an arbitrary position, 7 is a feed motor driver that drives the feed motor 6, and 8 is an LD that sends a drive current to the laser diode of the pickup unit 4. A driver 9 is a read amplifier for amplifying an RF signal obtained by the pickup unit 4, and 10 is a servo based on control of the feed motor 6, spindle motor driver 3, actuator driver 5, and RF signal from the read amplifier 9. A CD servo processor for performing control, 11 a CD encoder performing laser pulse control for recording data, 12 an ATIP detector for extracting ATIP from an output signal from the read amplifier 9, and 13 a laser power for the LD driver 8 by the CPU 16. DAC (DA converter), 14 is a buffer memory, and 15 is a CD-ROM decoder. 16 is a CPU, 17 is a ROM (storage means of the present invention), 17 a is a plurality of laser power setting tables provided for setting laser power corresponding to the reproduction speed ratio calculated by the CD servo processor 10, 18 Is the main memory.
[0022]
The CPU 16 makes logical judgments and calculations, and the ROM 17 has a program storage area in which a control program for causing the CPU 16 to function and a control program for the optical disc recording / reproducing apparatus are stored. Then, the CPU 16 is loaded with the control program read from the ROM 17 to constitute a control means as a function realization means, and executes a target function of each control program. That is, the CPU 16 controls the laser power for the LD driver 8 as control means. Similarly, the CD servo processor 10 is loaded with a program from a built-in memory of the chip, detects the rotation speed of the spindle based on the RF signal obtained from the pickup unit 4, acquires the actual data reproduction speed from this, and feeds it. Servo control of the motor 6, the spindle motor driver 3, the actuator driver 5, etc. is performed, and the reproduction speed ratio is calculated by taking the ratio of the actual data reproduction speed and the target data reproduction speed. Details of the control of the spindle motor 2 will be described below. Therefore, the CD servo processor 10 is also a servo control arithmetic unit configured as a function realizing unit by a program.
[0023]
When the CPU 16 requests the CD servo processor 10 to switch to the spindle rotation speed via the bus 19, the CD servo processor 10 changes the PWM output level to the spindle motor driver 3, and the spindle motor driver 3 receives the input. The rotational speed of the spindle motor 2 is changed according to the PWM output level. The CD servo processor 10 acquires the actual data reproduction speed based on the RF signal from the read amplifier 9 and controls the PWM output to the spindle motor driver 3 so as to achieve the target data reading speed. As described above, the playback speed ratio is calculated, and the CPU 16 can acquire the playback speed ratio through the bus 19.
[0024]
Next, the laser power setting table 17a according to Embodiment 1 of the present invention will be described. FIG. 2 is a table for setting laser power in which the relationship between the playback speed ratio and the laser power of the optical disc recording / playback apparatus according to Embodiment 1 of the present invention is set. As shown in FIG. 2, a plurality of laser power setting tables 17a are provided for each target data reproduction speed. The plurality of target data reproduction speeds are represented by target data reproduction speed 1 to target data reproduction speed m. There are also a plurality of reproduction speed ratios with respect to the target data reproduction speed of each laser power setting table 17a.
[0025]
For example, for the target data reproduction speed 1, the reproduction speed ratio A1 to the reproduction speed ratio N1. Similarly, there are a plurality of reproduction speed ratios with respect to the target data reproduction speed m, which are reproduction speed ratios Am to Nm. Then, the laser powers A1 to N1,..., Am to Nm correspond to the reproduction speed ratios A1 to N1,. For example, in FIG. 2, when the target data playback speed is the target data playback speed 1 and the actual playback speed ratio is the playback speed ratio A1, the laser power A1 corresponds.
[0026]
FIG. 3 is a flowchart showing a playback speed switching sequence of the optical disk recording / playback apparatus according to Embodiment 1 of the present invention. In the flowchart of FIG. 3, the case where the target data reproduction speed is 1 is described. The calculation according to this flowchart is executed by the CPU 16 loaded with the control program stored in the ROM 17 as a control function realization means.
[0027]
First, in S1, playback speed switching for changing to the target data playback speed 1 is started. In S2, the reproduction speed ratio is acquired from the CD servo processor 10, set in the variable P, and stored. S3 compares the variable P with the ratio A1 according to the condition 1 (whether P ≧ A1). If the variable P is equal to or greater than the ratio A1, the target data reproduction speed 1 and the ratio A1 are obtained from the laser power setting table 17a of FIG. Is acquired and set in the DAC 13 (S7).
[0028]
In S4, the variable P is compared with the ratio B1 in accordance with condition 2 (whether P ≧ B1). If the variable P is equal to or greater than the ratio B1, the target data reproduction speed 1 and the ratio are obtained from the laser power setting table 17a of FIG. The laser power B1 corresponding to B1 is acquired and set in the DAC 13 (S8).
[0029]
S5 compares the variable P with the ratio C1 according to condition 3 (whether P ≧ C1). If the variable P is equal to or greater than the ratio C1, the target data reproduction speed 1 and the ratio C1 are obtained from the laser power setting table 17a of FIG. Is acquired and set to the DAC 13 (S9).
[0030]
In S6, the variable P is compared with the ratio N1 according to the condition N (whether P ≧ N1). If the variable P is less than the ratio N1, S2 is repeated. If the variable P is greater than or equal to the ratio N1, the laser power N1 corresponding to the target data reproduction speed 1 and the ratio N1 is acquired from the laser power setting table 17a of FIG. 2, and set in the DAC 13 (S10). In this case, it is determined that the reproduction speed has reached the target data reproduction speed 1, and the reproduction speed switching ends in S11.
[0031]
FIG. 4 is a diagram showing the relationship between the reproduction speed and the laser power of the optical disk recording / reproducing apparatus according to Embodiment 1 of the present invention. The reference laser power is set as the laser power before changing the reproduction speed, and laser power A1, laser power B1, laser power C1,... Laser power N1 are stepwise from the start of reproduction speed switching to the end of reproduction switching. Is set to indicate that the laser power is increased. Then, it is shown that data can be read before changing the playback speed, after starting playback speed switching, ending playback speed switching, and after switching playback speed. Further, since the laser power is increased stepwise in the middle of the target rotation speed, excessive laser irradiation on the optical disk layer can be prevented.
[0032]
By the way, the most remarkable effect of the optical disk recording / reproducing apparatus of the first embodiment is the copying operation between the data in the own disk of the optical disk recorded by the packet write method. FIG. 5 is a configuration diagram of an optical disc recorded by the packet write method. In FIG. 5, the optical disk of the packet write system is a system in which the minimum unit of data on the optical disk S1 is regarded as one packet, and the recording / reproduction is made efficient by regarding the data as an aggregate of packets as in S4. Data to be read at a time when data in the self-disk shown in S2 of this packet write method (data to be read) is copied to another area (data recording area) in the self-disk shown in S3 Since the unit of data to be recorded is limited to a fixed number of packets, it is necessary to repeat data reading and data writing alternately several times when copying. However, according to the optical disc recording / reproducing apparatus of the first embodiment, it is possible to remove the time zone in which data cannot be read out, and the data reading start time can be shortened, so that the time required for copying can be shortened. It becomes.
[0033]
As described above, the optical disk recording / reproducing apparatus according to the first embodiment of the present invention switches from a low recording speed at the time of data writing to the optical disk to a high data reproducing speed for data reading, or a low speed recording speed. By switching from the reproduction speed for reading data to the reproduction speed for reading data at a high speed, it is possible to shorten the data reading start time when performing data reading.
[0034]
【The invention's effect】
As described above, according to the optical disk recording / reproducing apparatus of the present invention, when switching from a low recording speed during recording to a high reproducing speed during reproduction, or a low data reproducing speed during reproduction. When switching from a high playback speed to a high playback speed, the laser power can be increased stepwise until the target playback speed is reached, and data can be read without interruption until the target playback speed is reached. Data read start time can be shortened.
[0035]
Further, since the laser power is increased stepwise in the middle of the target rotation speed, excessive laser irradiation to the optical disk layer can be prevented, and physical destruction of each layer of the optical disk can be suppressed.
[0036]
Further, according to the data reproducing method of the optical disc recording / reproducing apparatus of the present invention, physical destruction of each layer of the optical disc can be prevented, data can be read without interruption of data reading, and the reproduction operation can be speeded up.
[Brief description of the drawings]
FIG. 1 is a block diagram of an optical disk recording / reproducing apparatus according to a first embodiment of the present invention. FIG. 2 is a laser power setting in which the relationship between the reproduction speed ratio and the laser power of the optical disk recording / reproducing apparatus according to the first embodiment of the present invention is set. FIG. 3 is a flowchart showing a playback speed switching sequence of the optical disk recording / playback apparatus according to the first embodiment of the present invention. FIG. 4 is a flowchart showing playback speed and laser power of the optical disk recording / playback apparatus according to the first embodiment of the present invention. FIG. 5 is a block diagram showing a configuration of a conventional optical disc recording / reproducing apparatus. FIG. 7 is a flowchart showing a playback speed switching sequence of the conventional optical disc recording / reproducing apparatus. FIG. 8 is a diagram of the relationship between reproduction speed and laser power of a conventional optical disk recording / reproducing apparatus. Description]
DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Spindle motor driver 4 Pickup unit 5 Actuator driver 6 Feed motor 7 Feed motor driver 9 Read amplifier 10 CD servo processor 11 CD encoder 12 ATIP detector 13 DAC
14 Buffer memory 15 CD-ROM decoder 16 CPU
17 ROM
17a Laser power setting table 18 Main memory 19 Bus

Claims (2)

A pickup unit for recording / reproducing data on a phase change type optical disc;
A spindle motor driver for controlling the rotation speed of the spindle;
Based on the RF signal obtained from the pickup unit, the number of rotations of the spindle is detected, the actual reproduction speed is obtained, servo control is performed on the spindle motor driver from the difference from the target reproduction speed, and the actual reproduction speed is obtained. Servo control calculation means for calculating the playback speed ratio by taking the ratio of the playback speed and the target playback speed;
Control means for controlling a laser driver to control the amount of laser light emitted from the pickup unit during recording and reproduction;
An optical disc recording / reproducing apparatus comprising: a control program for causing the control means to function; and a storage means for storing a plurality of laser power setting tables for setting laser power corresponding to the reproduction speed ratio,
When switching from low-speed recording to high-speed playback, or when switching from low-speed playback to high-speed playback, the control means uses the laser power setting table based on the target playback speed. The laser power corresponding to the reproduction speed ratio is set from the laser power setting table, the laser power is increased stepwise until the target reproduction speed is reached, and data is read without interruption. An optical disc recording / reproducing apparatus. A playback method for an optical disc recording / playback apparatus that switches from a low-speed recording operation or a low-speed playback operation to a high-speed playback operation, wherein a plurality of playback speed ratios represent a ratio between an actual playback speed and a target playback speed. And a plurality of laser power setting tables in which the corresponding laser power is related to the target playback speed, and step by step in the playback speed ratio until the target playback speed is reached based on the laser power setting table A method for reproducing data from an optical disk recording / reproducing apparatus, wherein the laser power is increased and data is read without interruption.

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