JPH08339614A - Disk reproducing device - Google Patents

Abstract

PURPOSE: To obtain a disk reproducing device of reduced power consumption. CONSTITUTION: After reproduction operation, double-speed reproduction and reproduction pause are alternately repeated, thus storing audio data which are constantly equal to or more than a certain amount in a DRAM 12 for preventing sound jump. Audio data are continuously read from the DRAM 12 at a standard speed and a reproduction audio signal is obtained at an output terminal 14. When the alternate operation of the double-speed reproduction and reproduction pause continues for a specific time, a state for continuously performing standard-speed reproduction is automatically initiated by the control of the microcomputer 20. In this case, the amount of data stored in the DRAM 12 is retained to be at a constant value. When the servo-lock state is disabled in the standard-speed reproduction, an intermittent operation of the double-speed reproduction above is initiated. When a state where the double-speed reproduction and reproduction pause are alternately performed (a motor 2 constantly rotates at the double speed of the standard rotary speed) continues for a specific amount of time, the standard-speed reproduction where the motor 2 rotates at a standard speed is initiated, thus reducing power consumption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a CD which outputs a reproduction signal at a constant speed through a memory means.
(Compact Disc) The present invention relates to a disc reproducing device such as a reproducing device. Specifically, by automatically shifting to a playback operation in which playback at a playback speed higher than the standard speed and playback pause are alternately repeated for a predetermined time or more, and then continuously played back at the standard speed, The present invention relates to a disc reproducing device designed to be reduced.

[0002]

2. Description of the Related Art FIG. 4 shows an example of the structure of a CD reproducing apparatus. The CD 1 is rotationally driven by the spindle motor 2. A laser beam from a semiconductor laser that constitutes the optical pickup 3 is applied to the recording surface of the CD 1, and the reflected light is applied to a plurality of photodetectors (for example, 6-division photodetectors) (not shown) that constitute the optical pickup 3.
Output signals of the plurality of photodetectors of the optical pickup 3 are supplied to the RF amplifier unit 4. For example, the tracking error signal by the three-spot method and the focus error signal by the stigma method obtained from the RF amplifier unit 4 are supplied to the servo control circuit 5, and the servo control circuit 5 performs tracking servo and focus servo of the optical pickup 3. Be seen.

The servo control circuit 5 also controls the rotation of the feed motor 6 for moving the optical pickup 3 to a predetermined position and the rotation of the spindle motor 2. The operation of the servo control circuit 5 is controlled by a microcomputer (hereinafter, referred to as "microcomputer") 7 that constitutes a system controller. The microcomputer 7 is connected to a key operation unit 8 for the user to perform various operations, and is also connected to a display 9 for displaying an operation procedure by the key operation unit 8 and a system state.

A reproduction R obtained from the RF amplifier unit 4
F signal is EFM (Eight to Fourteen Modulation) and C
The signal is supplied to an IRC (Cross Interleave Reed-Solomon Code) decoder 10 and subjected to EFM demodulation processing and error correction processing. The audio data error-corrected by the decoder 10 is stored in the memory controller 11
DRAM for preventing skipping (dynamic RA
M) is temporarily stored in 12. Even if not described above, the reading of audio data from the CD 1 is performed intermittently at a speed twice as high as the standard speed, so that a certain amount or more of audio data is always stored in the DRAM 12.

The audio data stored in the DRAM 12 are sequentially read out at a standard speed (constant speed) under the control of the memory controller 11, and the D / A converter 1
3 and is converted into an analog signal. And D
The reproduced audio signal output from the / A converter 13 is led to the output terminal 14.

FIG. 5 is a flow chart showing the reproducing operation under the control of the microcomputer 7. In the figure, when the user performs a reproduction operation with the key operation unit 8, first, step ST1.
Servo operation for double speed playback. In this case, the rotation of the spindle motor 2 is controlled by the servo control circuit 5, and CLV (Constant Linear Verocit) for double speed reproduction is controlled.
y) Servo is mainly performed. And step ST
2, focus servo, tracking servo, CLV
It is determined whether or not the servo is in a servo lock state (a state in which audio data can be favorably reproduced from CD1),
The servo operation is performed in step ST1 until the servo lock state is achieved.

When it is determined in step ST2 that the servo is locked, the double speed reproduction and the reproduction pause operation are alternately repeated in step ST3 until the servo lock is not determined in step ST4.
A certain amount of audio data is always accumulated in 12 (the motor 2 always rotates at twice the standard rotation speed). For example, first, playback is performed at double speed until the data storage amount of the DRAM 12 increases to about 90%, then DR
The reproduction pause state is set until the data storage amount of the AM12 decreases to about 60%, and then the data is reproduced at double speed until the data storage amount of the DRAM12 increases to about 90%.
The double speed reproduction and reproduction pause operations are repeated so that the data storage amount of No. 2 changes at 60 to 90%.

When it is determined in step ST4 that the servo is not in a locked state due to defocusing due to an external shock, the following operation is performed in order to prevent skipping (interruption of sound). That is, step ST
At 5, the servo operation for double speed reproduction is performed. In this case, when the focus is out of the range of the focus servo, the focus servo and the tracking servo are turned on after the focus search operation for searching the focus position is performed, and the CLV servo is performed. Becomes Then, in step ST6, it is determined whether or not the servo is locked, and the servo operation is performed in step ST5 until the servo is locked.

When it is determined in step ST6 that the servo lock state is set, in step ST7, the playback position of the CD1 is moved to the playback position at the time when the servo lock state is removed (hereinafter referred to as "sound skip position"). Search for. Then, in step ST8, it is determined whether or not the search for the sound skip position is completed, and the search operation is performed in step ST7 until the search for the sound skip position is completed.

Here, the search operation is performed by using the absolute time information based on the sub-coding Q channel data. As is well known, one block of sub-coding is composed of 98 frames, but since two frames are a synchronization signal for identifying the head of the block, it is substantially 9
One block of sub-coding is composed of 6 frames. Figure 6 is a sub-coding Q shows the frame structure of the channel, Q ₁ to Q ₄ control data (4 bits), Q ₅ to Q ₈ (4 bits) of the address data, Q ₉
To Q ₈₀ (72 bits) data and Q _{81 to} Q ₉₆ (16 bits) CRC (Cyclic Redundancy Code). The absolute time information used in the above search operation is
It is provided by using a part of the data of Q _{9 to} Q ₈₀ .

When the search for the sound skip position is completed in step ST8, the process returns to step ST3 to restart the double speed reproduction and the reproduction pause operation from the sound skip position. If the data storage amount of the DRAM 12 does not become zero by the time the search for the sound skip position is completed and the double speed reproduction operation is restarted, the reproduced audio signal obtained at the output terminal 14 is not interrupted. Sound skip is prevented.

FIG. 7 shows the transition of the amount of data stored in the DRAM 12. When the user performs a reproduction operation on the key operation unit 8 at time t ₀ and the servo lock state in the double speed reproduction is started at time t ₁ , reproduction of the CD 1 is started, the DRAM is
The audio data stored in 12 gradually increases.
Then, when the storage amount of the DRAM 12 becomes about 20% at the time point t ₂ , the reading of the audio data from the DRAM 12 is started, and the reproduced audio signal is obtained at the output terminal 14. When the reading of the audio data from the DRAM 12 is started in this way, the rate of increase of the audio data stored in the DRAM 12 is naturally reduced.

When the data storage amount of the DRAM 12 reaches about 90% at the time point t ₃ , a reproduction pause is set, and DR is performed.
The amount of data accumulated in the AM 12 gradually decreases. When the data storage amount of the DRAM 12 reaches about 60% at the time point t ₄ , the double speed reproduction is started again, so that the data storage amount of the DRAM 12 gradually increases again. Hereinafter, similarly, the DRAM 12
The amount of data accumulated in is changed.

In such a state, for example, when there is an external shock at the time t ₅ and the servo lock state is lost,
Until the servo lock state for double speed playback is resumed, and the search for the skip position is completed and double speed playback is started,
The amount of data stored in the DRAM 12 decreases. And
When the double speed reproduction starts at time t ₆ , the data storage amount of the DRAM 12 gradually increases again.

[0015]

In the CD reproducing apparatus of FIG. 4 described above, the power consumption is large because the CD1 is constantly rotated by the spindle motor 2 at twice the standard rotation speed, that is, double speed. In a portable CD reproducing device that uses a CD, it is difficult to reproduce for a long time.

Therefore, the present invention provides a disc reproducing apparatus capable of reducing power consumption.

[0017]

DISCLOSURE OF THE INVENTION A disk reproducing apparatus according to the present invention comprises a signal reproducing means for reproducing a signal from a disk-shaped recording medium, a reproducing operation control means for controlling a reproducing operation of the signal reproducing means, and a signal. Memory means for temporarily accumulating the signal reproduced from the disk-shaped recording medium by the reproducing means, and writing the signal reproduced from the disk-shaped recording medium by the signal reproducing means into the memory means, and a standard speed from this memory means. And a memory control means for obtaining a reproduction output signal by the signal reproduction means, and the signal reproduction means continuously reproduces the first reproduction mode and the reproduction at the reproduction speed higher than the standard speed and the reproduction pause alternately. And a second reproduction mode in which the reproduction operation is performed in the first reproduction mode for a predetermined time. When carried out continues, and in which a reproduction operation by the signal reproducing means for controlling so as to shift to the second reproduction mode.

[0018]

For example, when a reproduction operation is performed by the user, the signal reproduction means enters the first reproduction mode in which the reproduction at the reproduction speed higher than the standard speed and the reproduction pause are alternately repeated,
A reproduction signal of a certain amount or more is always accumulated in the memory means.
Then, when the signal reproducing means performs the reproducing operation in the first reproducing mode continuously for a predetermined time, the signal reproducing means shifts to the second reproducing mode in which the reproducing is continuously performed at the standard speed. In this way, when the signal reproduction means is in the first reproduction mode and the second reproduction mode, the signal is read from the memory means at the standard speed and the reproduction output signal is obtained. When the signal reproduction means is in the second reproduction mode, the signal storage amount of the memory means is held at a constant value.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the disc reproducing apparatus according to the present invention will be described below with reference to FIG. This example is an example applied to a CD reproducing device. In FIG. 1, FIG.
The parts corresponding to are indicated by the same reference numerals.

The CD 1 is rotationally driven by the spindle motor 2. A laser beam from a semiconductor laser that constitutes the optical pickup 3 is applied to the recording surface of the CD 1, and the reflected light is applied to a plurality of photodetectors (for example, 6-division photodetectors) (not shown) that constitute the optical pickup 3. Output signals of the plurality of photodetectors of the optical pickup 3 are supplied to the RF amplifier unit 4. A tracking error signal obtained by, for example, the three-spot method and a focus error signal obtained by the stigma method, which are obtained from the RF amplifier unit 4, are supplied to the servo control circuit 5.
Thus, tracking servo and focus servo of the optical pickup 3 are performed.

The servo control circuit 5 also controls the rotation of the feed motor 6 for moving the optical pickup 3 to a predetermined position and the rotation of the spindle motor 2. The operation of the servo control circuit 5 is performed by the microcomputer 2 that constitutes the system controller.
Controlled by 0. The microcomputer 20 is connected to a key operation unit 8 for the user to perform various operations, and is also connected to a display 9 for displaying an operation procedure by the key operation unit 8 and a system state.

A reproduction R obtained from the RF amplifier unit 4
The F signal is supplied to the EFM and CIRC decoder 10.
The EFM demodulation process is performed, and the error correction process is performed. The audio data error-corrected by the decoder 10 is temporarily stored in the sound skip prevention DRAM 12 via the memory controller 11.

Although not described above, the reading of audio data from the CD 1 is first performed intermittently at a speed twice as high as the standard speed, and is controlled so that the DRAM 12 always accumulates a certain amount or more of audio data. To be done. When such intermittent reading of audio data from the CD 1 is continuously performed for a predetermined time, for example, 30 seconds, the CD
The reading of audio data from 1 is controlled so as to be continuously performed at the standard speed. Further, when the audio data is continuously read from the CD 1 at the standard speed, and when the servo lock state is lost due to a focus loss due to an external shock as described later, the audio data is read from the CD 1. Is again controlled to be intermittent at a speed twice the standard speed.

The audio data stored in the DRAM 12 is sequentially read out at a standard speed under the control of the memory controller 11, supplied to the D / A converter 13 and converted into an analog signal. Then, the D / A converter 13
The reproduced audio signal output from the output terminal is output to the output terminal 14. Since the audio data stored in the DRAM 12 is sequentially read at the standard speed, the data storage amount of the DRAM 12 increases when the audio data is read from the CD 1 at a speed twice the standard speed. At the same time, it is held at a constant value when performed at a standard speed.

FIG. 2 is a flow chart showing the reproducing operation under the control of the microcomputer 20. In the figure, when the user performs a reproduction operation with the key operation unit 8, first, step ST
At 11, the servo operation for double speed reproduction is performed. In this case, the rotation of the spindle motor 2 is controlled by the servo control circuit 5, and CLV servo for double speed reproduction is mainly performed. Then, in step ST12, the focus servo,
It is determined whether or not there is a servo lock state (a state in which audio data can be favorably reproduced from the CD1) such as tracking servo and CLV servo, and the servo operation is performed in step ST11 until the servo lock state is reached.

When it is determined in step ST12 that the servo is locked, the double speed reproduction and the reproduction pause operations are alternately repeated in step ST13 until it is determined that the servo is not locked in step ST14.
The RAM 12 is controlled so as to always store a certain amount or more of audio data (the motor 2 always rotates at twice the standard rotation speed). For example, initially DRAM12
Playback is performed at double speed until the data storage amount of the DRAM 12 increases to about 90%, then the playback pause state is set until the data storage amount of the DRAM 12 decreases to about 60%, and then the data storage amount of the DRAM 12 increases to about 90%. The reproduction is repeated at a double speed until the above, and thereafter, the double speed reproduction and the reproduction pause operation are repeated so that the data storage amount of the DRAM 12 changes at 60 to 90%.

Further, as described above, in the state where the double speed reproduction and the reproduction pause operation are alternately performed in step ST13, it is determined in step ST15 whether or not a predetermined time, for example, 30 seconds has elapsed, and the predetermined time is determined. When the time has elapsed, it is determined in step ST16 whether the data storage amount of the DRAM 12 is the maximum (about 90%). And step S
When it is determined that the data storage amount is the maximum at T16,
In step ST17, the servo operation for standard speed reproduction is performed.
In this case, the servo control circuit 5 controls the rotation of the spindle motor 2 so that the CLV for reproducing at the standard speed.
Servo is mainly performed. Then, step ST18
Then, it is determined whether or not there is a servo lock state such as focus servo, tracking servo, CLV servo (a state in which audio data can be favorably reproduced from CD1), and the servo operation is performed in step ST17 until the servo lock state is reached. .

When it is determined in step ST18 that the servo is locked, control is performed in step ST19 to continuously perform reproduction at the standard speed until it is determined in step ST20 that the servo is not locked.
Rotates at standard speed). In this case, the DRAM 12
The data storage amount of is held at a constant value.

When it is determined in step ST14 or step ST20 that the servo is not in a locked state due to an external shock or the like, the following operation is performed in order to prevent skipping (sound break). . That is, the servo operation for double speed reproduction is performed in step ST21. In this case, when the focus is out of the range of the focus servo, the focus servo and the tracking servo are turned on after the focus search operation for searching the focus position is performed, and the CLV servo is performed. Becomes Then, in step ST22, it is determined whether or not the servo is locked, and the servo operation is performed in step ST21 until the servo is locked.

When it is determined in step ST22 that the servo lock state is set, in step ST23, the playback position of the CD1 is moved to the playback position at the time when the servo lock state is lost (hereinafter referred to as "sound skip position"). Search for. Then, in step ST24, it is determined whether or not the search for the sound skip position is completed, and the search operation is performed in step ST23 until the search for the sound skip position is completed. Here, as in the case of the example of FIG. 4, the search operation is performed by sub-coding Q channel data (see FIG. 6).
It is performed by using absolute time information by.

When the search for the sound skip position is completed in step ST24, the process returns to step ST13 to restart the double speed reproduction and reproduction pause operations of step ST13 from the sound skip position. By the time the search for the sound skip position is completed and the double speed reproduction operation is restarted in this way, the DRAM 12
If the data storage amount of is not zero, the reproduced audio signal obtained at the output terminal 14 is not interrupted, and skipping of sound is prevented.

FIG. 3 shows the transition of the data storage amount of the DRAM 12. When the user performs a reproduction operation on the key operation unit 8 at time t ₀ and the servo lock state in the double speed reproduction is started at time t ₁ , reproduction of the CD 1 is started, the DRAM is
The audio data stored in 12 gradually increases.
Then, when the storage amount of the DRAM 12 becomes about 20% at the time point t ₂ , the reading of the audio data from the DRAM 12 is started, and the reproduced audio signal is obtained at the output terminal 14. When the reading of the audio data from the DRAM 12 is started in this way, the rate of increase of the audio data stored in the DRAM 12 is naturally reduced.

When the data storage amount of the DRAM 12 reaches about 90% at the time point t ₃ , the reproduction pause is set, and DR is performed.
The amount of data accumulated in the AM 12 gradually decreases. When the data storage amount of the DRAM 12 reaches about 60% at the time point t ₄ , the double speed reproduction is started again, so that the data storage amount of the DRAM 12 gradually increases again. Hereinafter, similarly, the DRAM 12
The amount of data accumulated in is changed.

This is because the servo operation for standard speed reproduction is started at time t ₁₁ when the data storage amount of the DRAM 12 reaches the maximum (about 90%) after a predetermined time, for example, 30 seconds has passed in such a state. The amount of data stored in the DRAM 12 decreases. At time t ₁₂ , when the servo lock state in the standard speed reproduction is set and the reproduction of the CD 1 is started, the DRAM 1
The data storage amount of 2 is held at a constant value.

As described above, when the CD 1 is being reproduced at the standard speed, and the servo lock state is lost due to an external shock at time t ₁₃ , for example, the servo lock state for double speed reproduction is again established, and Until the search for the skip position is completed and the double speed reproduction is started, the DRAM 12
The amount of data accumulated in is decreasing. Then, when the double speed reproduction is started at the time point t ₁₄ , the data storage amount of the DRAM 12 gradually increases again.

The transition of the data storage amount of the DRAM 12 when the double speed reproduction and the reproduction pause are alternately performed and the servo lock state is lost due to an external shock has been described with reference to FIG. Is similar to.

As described above, according to the present embodiment, when the double speed reproduction and the reproduction pause are alternately performed for a predetermined time, the standard speed reproduction is automatically performed continuously. Since the rotation of the motor 2 is controlled to the standard rotation speed, power consumption can be reduced.
As a result, in a portable CD reproducing device using a battery, the battery life can be extended and the continuous reproducing time can be lengthened.

Further, according to this example, since the servo operation for the standard speed reproduction is started after the data storage amount of the DRAM 12 is maximized, the DRAM 12 which is held when the reproduction at the standard speed is continuously performed. The data storage amount can be made relatively large. Therefore, it is possible to reduce the possibility that the amount of data stored in the DRAM 12 becomes zero before the double speed reproduction is started after the servo lock state is lost due to an external shock or the like, and it is possible to favorably prevent skipping.

Further, according to this example, when the standard speed reproduction is continuously performed and the servo lock state is lost due to an external shock or the like, the servo operation for the double speed reproduction is performed and the double speed reproduction is performed. Since the data storage amount of the DRAM 12 is immediately increased by starting the operation, it is possible to reduce the possibility that the data storage amount of the DRAM 12 becomes zero when the servo lock state is removed next time, and to improve the sound skipping. It can be prevented.

In the above embodiment, the DRAM 1
Although the double speed reproduction and the reproduction pause are alternately repeated in order to keep the data storage amount of 2 above a certain amount, the reproduction may be performed at a reproduction speed higher than the standard speed instead of the double speed reproduction. Further, although the above-mentioned embodiment is applied to the CD reproducing apparatus, it is needless to say that the present invention can be similarly applied to other disk reproducing apparatuses for reproducing a signal from the disk recording medium.

[0041]

According to the present invention, the reproducing operation in which the reproducing operation at a reproducing speed larger than the standard speed and the reproducing pause are alternately repeated is automatically transferred to the reproducing operation of continuously reproducing at the standard speed after the continuous operation for a predetermined time. Therefore, the power consumption of the motor for rotating the disk-shaped recording medium can be reduced. For example, in a portable disc reproducing device that uses a battery, the battery life can be extended,
There is a benefit that the continuous playback time can be extended.

Further, by controlling so as to shift to the reproducing operation of continuously reproducing at the standard speed at the timing when the signal storage amount of the memory means becomes maximum, it is held when the reproduction at the standard speed is continuously performed. The signal storage amount of the memory means can be made relatively large, and it is possible to reduce the possibility that the signal storage amount of the memory means becomes zero before the reproduction is restarted after the servo lock state is lost due to an external shock. Good prevention of jumps.

Further, when the servo lock state is lost in the state where the reproduction at the standard speed is continuously performed, control is performed so as to shift to the reproduction operation in which the reproduction at the reproduction speed higher than the standard speed and the reproduction pause are alternately repeated. By doing so, since the signal storage amount of the memory means immediately increases, it is possible to reduce the possibility that the signal storage amount of the memory means becomes zero when the servo lock state is lost next time, and it is possible to prevent the sound skipping satisfactorily.

[Brief description of drawings]

FIG. 1 is a system diagram showing a configuration of an embodiment of a disc reproducing apparatus according to the present invention.

FIG. 2 is a flowchart showing a reproducing operation in the embodiment.

FIG. 3 is a diagram for explaining a transition of a data storage amount of DRAM in the embodiment.

FIG. 4 is a system diagram showing a conventional example of a CD reproducing device.

FIG. 5 is a flowchart showing a reproducing operation in a conventional example.

FIG. 6 is a diagram showing a frame structure of a sub-coding Q channel.

FIG. 7 is a diagram for explaining a transition of a data storage amount of DRAM in a conventional example.

[Explanation of symbols]

 1 Compact Disc (CD) 2 Spindle Motor 3 Optical Pickup 4 RF Amplifier Section 5 Servo Control Circuit 6 Feed Motor 8 Key Operation Section 9 Display 10 Decoder 11 Memory Controller 12 DRAM (Dynamic RAM) 13 D / A Converter 14 Output Terminal 20 Microcomputer

Claims (3)

[Claims] 1. A signal reproducing means for reproducing a signal from a disk-shaped recording medium, a reproduction operation control means for controlling a reproduction operation of the signal reproducing means, and a signal reproduced from the disk-shaped recording medium by the signal reproducing means. Memory means for temporarily storing the signal, and the signal reproduced from the disk-shaped recording medium by the signal reproducing means is written into the memory means, and the signal is read from the memory means at a standard speed and reproduced and output. A memory control means for obtaining a signal, wherein the signal reproduction means continuously reproduces at a first reproduction mode in which a reproduction at a reproduction speed higher than a standard speed and a reproduction pause are alternately repeated; A second reproduction mode, wherein the reproduction operation control means is the signal reproduction means.
When the reproducing operation in the reproducing mode is continuously performed for a predetermined time, the reproducing operation by the signal reproducing means is controlled so as to shift to the second reproducing mode. 2. The reproduction operation control means controls the reproduction operation by the signal reproduction means to shift to the second reproduction mode at the timing when the signal storage amount of the memory means is maximized. The disc reproducing apparatus according to claim 1. 3. A servo lock state determining means for determining whether or not the signal reproducing means is in a servo lock state capable of reproducing a signal from the disc-shaped recording medium, and the reproducing operation of the signal reproducing means is the first operation. When the servo lock determination means determines that the servo lock state is not established in the second reproduction mode, the reproduction operation control means shifts the reproduction operation by the signal reproduction means to the first reproduction mode. The disc reproducing apparatus according to claim 1, wherein the disc reproducing apparatus is controlled as follows.