JP3329862B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for recording an information signal such as a video signal on an optical disk and reproducing the recorded information signal.

[0002]

2. Description of the Related Art An optical disk device is provided with a tracking servo device for accurately reading out a signal recorded on a track on an optical disk by a pickup. As a tracking servo system, a three-beam system and a push-pull system are generally used.

In the three-beam method, a main beam spot to be positioned on a track and two sub-beam spots are formed at positions obliquely symmetric about the main beam spot, and the amount of light reflected by the two sub-beam spots And the difference is generated as a tracking error signal,
The objective lens is controlled so as to follow the track according to the tracking error signal.

In the push-pull system, the amount of light reflected by one beam spot to be positioned on a track is detected by a two-divided photodetector, and the difference between the divided outputs is generated as a tracking error signal. In a read-only optical disk device, generally, a three-beam tracking servo device capable of obtaining a stable operation has been used. On the other hand, in an optical disk device capable of recording, three operation modes of recording, reproduction and erasing are performed, so that a push-pull method is adopted as a tracking servo method in which a level fluctuation of a tracking error signal is small between an unrecorded portion and a recorded portion. ing.

[0005]

Since the tracking error signal by the three-beam method indicates the brightness of the reflected light, the signal amplitude becomes extremely small for an unrecorded portion of the disk as shown in FIG. When a recordable disc is reproduced by a read-only optical disc apparatus equipped with a three-beam type tracking servo device, when the pickup reaches an unrecorded portion of the disc, a servo loop is not formed due to a sudden decrease in the amplitude of a tracking error signal, and the pickup is not picked up. There is a problem that the beam spot runs away due to the above.

When writing or reading data managed in sector units on a disk, it is unlikely that the pickup reaches an unrecorded portion, but it is already recorded in additional recording when handling an information signal that is continuous data. There is a possibility that an unrecorded portion will be formed at the joint with the bent portion. SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disc apparatus capable of obtaining a stable tracking operation even when a disc on which additional recording is performed is reproduced by a three-beam type reproduction-only player.

[0007]

Means for Solving the Problems An optical disc device of the present invention, there is provided an optical disk apparatus for reproducing the recorded information signals and recording information signals on the optical disc, the optical disc writing information signals and a recording signal of the optical disc A pickup for reading and information signal recording by the pickup.
Recorded part formed on optical disc during recording, and unrecorded
Level hold to hold the level read from each of the units
Means and, held in the level holding means to move the pickup output level of the pickup on the optical disc when recording on the optical disc of the information signal to be additionally recorded
A discriminating unit for discriminating whether the pickup is in a recorded portion or an unrecorded portion on the optical disk by comparing the pickup with an unrecorded portion in accordance with a discrimination result of the discriminating portion. It is characterized by comprising a driving means for moving the pickup so as to be positioned at the immediately preceding recording section, and a means for starting additional recording after the movement driving by the driving means is completed. Furthermore, the optical disk device of the present invention is an optical disk
Record information signal on disk and reproduce the recorded information signal
An optical disc device for writing information signals on an optical disc.
For picking up and reading the recording signal of the optical disk
Up and pickup to record information signals
Recorded portion, unrecorded portion, and overlap formed on optical disc
A level that holds the level read from each of the writers
Holding means and image memory means for storing video data
Of the recorded information signal to be reproduced from the optical disc.
The pickup on the optical disk
Output level of the backup and held by the level holding means
By comparing with the level, the pickup
Whether it is in a recorded part, unrecorded part, or overwritten part
The pitch is determined based on the determination means for determining and the determination result of the determination means.
If the backup is in the recording area on the optical disk,
The pickup lights up to the side that outputs the recording information signal of the disc.
If the disc is in the unrecorded or overwritten area,
Output side of video data stored in image memory means
Switching means for switching to
You .

[0008]

[Action] In the optical disk apparatus of the present invention, the pickup on the optical disc is moved during the recording of the optical disc of the information signal to be additional recording, it is stored in the output level and the level holding means of the pickup during the movement Rule
By comparison with the bell, pickup whether the one of the recording portion and the unrecorded portion on the optical disc is discriminated, the pickup according to the determination result is moved to the recording portion position of the unrecorded portion immediately before additional recording operation Is started. More
In the optical disk device of
On the optical disk during playback from the optical disk
The pickup is moved, and the pickup
Ratio between output level and level held by level holding means
By comparison, the pickup was recorded on the optical disc,
It is determined whether it is in the recording section or the overwriting section.
Pickup is recorded on the optical disc
If it is in the section, the recording information signal of the optical disc is output.
The pickup is unrecorded on the optical disc,
If it is in the writing section, the video stored in the image memory
The output data is output.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the optical disk device according to the present invention shown in FIGS. 2 and 3, the optical pickup 1 is for recording and reproduction, has a semiconductor laser 53, and irradiates the disk 2 with laser light emitted from the semiconductor laser 53.
The semiconductor laser 53 of the pickup 1 has a laser drive circuit 5
2 driven. The laser light emitted from the semiconductor diode 53 is converted into a parallel laser beam by a collimator lens 54, the traveling direction is changed by a prism 55, and then supplied to a beam splitter 56. The parallel laser beam that has passed through the beam splitter 56 is a λ / 4 plate 5
After passing through 7, the light is converged on the recording surface of the disk 2 by the objective lens 58. The reflected light of the disk 2 returns to the beam splitter 56 via the objective lens 58 and the λ / 4 plate 57 and is separated. The separated reflected light enters the photodetector 3 via the light receiving lens 59. ing. A recording signal is supplied to the laser drive circuit 52 via the modulation circuit 51.
The photodetector 3 is divided into four parts as shown in FIG. 4, and receives the reflected light of the main beam. Each of the divisions a to d of the detector 3 is composed of a photodiode. The current flowing through each photodiode is detected as a voltage by a current-voltage converter (not shown).

The total voltage of the output voltages of the four divisions a to d of the detector 3 is detected by the adder 7, and the total voltage of the output voltages of the divisions a and d is calculated by the adder 8 by the divisions b and c. Are output by the adder 9. Further, the sum voltage of the output voltages of the dividing parts a and c is added by the adder 10, and the sum voltage of the output voltages of the dividing parts b and d is
Respectively. The capacitor 12 is connected to the output of the adder 7, and supplies only the AC component of the output signal of the adder 7 to the RF amplifier 13. The output RF signal of the RF amplifier 13 is an HPF (high-pass filter) 1
4, the demodulation circuit 1 converts only the video signal band component to
5 is supplied. The video signal demodulated by the demodulation circuit 15 is supplied to a changeover switch 19 and converted into digital video data by an A / D converter 16.
It is supplied to the memory controller 17. The memory controller 17 controls writing and reading of data to and from the image memory 18. The image memory 18 has a FIFO (Fi
rst in first out) and has a capacity to store a video signal for one frame. The video data read from the image memory 18 is supplied from the memory controller 17 to the D / A converter 20. The D / A converter 20 converts video data into an analog video signal. The changeover switch 19 selectively supplies one of the video signal demodulated by the demodulation circuit 15 and the video signal converted by the D / A converter 20 to the display device.

The output voltage of the adders 8 and 9 is
Supplied to The output signal of the differential amplifier 25 is converted into digital data by an A / D converter 26 and then supplied to a memory controller 27. Memory controller 27
Controls writing and reading of data to and from the memory 28. Data read from the memory 28 by the memory controller 27 is converted into an analog signal by the D / A converter 29 and then supplied to the differential amplifier 30. The differential amplifier 30 subtracts the output signal of the D / A converter 29 from the tracking error signal directly output from the differential amplifier 25, and the output signal of the differential amplifier 30 is used as a push-pull tracking error signal. The push-pull tracking error signal is supplied to the tracking servo circuit 23 via the switch 34. The tracking servo circuit 23 drives the tracking actuator 24 according to the supplied tracking error signal.

The output voltages of the adders 10 and 11 are supplied to a differential amplifier 31. The output signal of the differential amplifier 31 is a focus error signal. A focus servo circuit 32 is connected to an output of the differential amplifier 31. The focus servo circuit 32 drives the focus actuator 33 according to the supplied focus error signal. A DC amplifier 35 is connected to the output of the adder 7. D
A microcomputer 37 is connected to an output of the C amplifier 35 via an A / D converter 36. DC amplifier 3
5 are supplied to first to third level holding circuits 38 to 40.
And first to third comparison circuits 41 to 43 are connected. The holding operation of the level holding circuits 38 to 40 is controlled by the microcomputer 37. Level holding circuit 38
40 are supplied to the corresponding comparison circuits 41 to 43. The comparison outputs of the comparison circuits 41 to 43 are supplied to the microcomputer 37.

The microcomputer 37 is a system controller, and controls switching of the changeover switch 19 and on / off of the switch 34 by a control operation described later. The microcomputer 37 supplies a track jump command signal to the tracking servo circuit 23, and controls the operation of a slider drive circuit 46 that drives a slider motor 45 that moves the entire pickup 1 in the radial direction of the disk 2. The slider drive circuit 46 drives the slider motor 45 according to the drive signal level of the tracking actuator 24. Microcomputer 37
Is connected to a display 47.

A spindle motor 48 for rotating the disk 2 is driven by a spindle drive circuit 49. The spindle drive circuit 49 drives the spindle motor 48 according to a synchronization signal in which an output signal of the demodulation circuit 15 is separated and extracted by means not shown. The rotation of the spindle motor 48 is detected by a rotation detector 50. Rotation detector 5
0 generates a pulse signal every time the spindle motor 48 makes one rotation and supplies it to the memory controller 27.

In such a configuration, the adders 8 and 9 are provided by the respective dividing units a to d of the detecting unit 3 for receiving the reflected light of the main beam.
The (a + d) component and the (c + b) component which are the output voltages of are supplied to the differential amplifier 25. The output signal ((a + d) component− (c + b) component) of the differential amplifier 25 is converted into digital data by the A / D converter 26 and then supplied to the memory controller 27. Since the memory controller 27 receives a pulse signal from the rotation detector 50 every time the spindle motor 48 makes one rotation, it outputs the output signal of the differential amplifier 25 from the time when one pulse signal is generated until the time when the next pulse signal is generated. The data is sequentially written to the memory 28. The output signal of the differential amplifier 25 is a residual error component due to the eccentricity of the disk 2.

Digital data of a residual error component due to disk eccentricity is read from the memory 28 by the controller 27 and supplied to the D / A converter 29 in synchronization with the pulse signal from the rotation detector 50. D / A converter 29
Converts analog data into analog data and supplies the analog data to the differential amplifier 30. The differential amplifier 30 reads out the residual error component from the output signal of the differential amplifier 25 and supplies the result to the tracking servo circuit 23 via the switch 34 as a tracking error signal. Therefore, the tracking actuator 24 is
To be a push-pull tracking servo.

When recording a desired video signal on the disk 2, the microcomputer 37 first issues a command to the slider drive circuit 46 to move the pickup 1 to the innermost track of the disk 2 as shown in FIG. Occurs (step S1). It is determined whether or not the pickup 1 has reached the innermost track (step S2). When the pickup 1 reaches the innermost track, an instruction to record a predetermined signal for a second predetermined time after a first predetermined time is issued (step S3). As a result, circuits such as the drive circuits and the servo circuits operate to record a predetermined signal only on a part of the innermost track. At this time, since the DC level of the reflected light of the laser beam is supplied to the microcomputer 37 as a digital value, the drive of the laser drive circuit 52 is controlled to control the laser power emitted from the semiconductor laser 53 in accordance with the digital value. Controlling the level is performed. Such a predetermined signal may be a signal that is merely a laser beam irradiation or a random signal.

The microcomputer 37 determines in step S3
After the execution of the above, an operation to record a predetermined signal in a part of the recording section of the innermost track is instructed (step S4). That is, overwriting is performed on a part of the recording portion of the innermost track formed by the execution of step S3. Therefore,
In terms of time, the recording operation takes a shorter time than the second predetermined time, and three portions of an unrecorded portion, a recorded portion, and an overwritten portion are sequentially formed on the innermost track from the starting point. After the execution of step S4, a command to start recording the video signal is issued (step S5).

On the other hand, when the signal is recorded on the disk 2 as described above, the microcomputer 37 first picks up the slider drive circuit 46 as shown in FIG. A command to move 1 to the innermost track of the disk 2 is generated (step S11). It is determined whether or not the pickup 1 has reached the innermost track (step S12). When the pickup 1 reaches the innermost track, it instructs an operation of reading the signal of the innermost track (step S1).
3).

The microcomputer 37 is a DC amplifier 3
5 is read from the output value of the D / A converter 36 at every predetermined timing and is sampled (step S14). At this time, the first level holding circuit 38 holds the DC level sampled first from the start point of the innermost track as the unrecorded portion level A (step S1).
5). Next, it is determined whether or not sampling of a DC level different from the DC level A has been performed (step S1).
6). If the level change matches, the DC level is stored in the second level holding circuit 39 as the recording section level B (step S17). Further, it is determined whether or not sampling at a DC level different from the DC level B has been performed (step S18). If the level change matches, the DC level is held in the third level holding circuit 40 as the overwriting portion level C (step S19). After obtaining the DC levels A, B, and C, it is determined whether or not the DC levels have a relation of A>B> C or A <B <C (step S20). If the DC levels A, B, and C do not satisfy any of the above relationships, it is determined that the sampling operation is wrong, and the process shifts to step S11 to repeat the above operation.
When the DC level is in the relationship of A>B> C or A <B <C, a video signal reproducing operation is instructed (step S2).
1). Note that A>B> C is for a disc whose reflectance decreases when recorded, and A <B <C is for a disc whose reflectivity increases. For example, in the case of a CD-R, A>B> C.

In the reproducing operation, the read RF signal output from the pickup 1 is sent to the HP
The signal is supplied to the demodulation circuit 15 as only the video signal band component in the HPF 14. Demodulation circuit 1
The video signal demodulated in 5 is supplied to the display device via the changeover switch 19. The demodulated video signal is supplied to the memory controller 17 as digital video data in the A / D converter 16.
The memory controller 17 sequentially designates a write address of the image memory 18 in accordance with the horizontal synchronization signal and the vertical synchronization signal separated by the synchronization separation circuit, and writes video data to a storage position of the write address. Further, a read address is sequentially designated, video data is read from the read address, and supplied to the D / A converter 20. In the D / A converter 20, the video data is converted into an analog video signal, which is supplied to the changeover switch 19. The changeover switch 19 is normally in a state of relaying the video signal demodulated by the demodulation circuit 15 as it is.

If the output DC level of the DC amplifier 35 is equal to the level held in the level holding circuit 38 and the comparison circuit 41 has a high-level output indicating that the DC levels match, the reading position of the pickup 1 is set to the unrecorded portion. It is in.
If the output DC level of the DC amplifier 35 is equal to the level held in the level holding circuit 40 and the comparison circuit 43 has a high-level output indicating that the DC levels match, the reading position of the pickup 1 is set to the overwriting portion. is there. The microcomputer 37 switches the changeover switch 19 to the output side SA of the demodulation circuit 15 at the time of reproduction of the recording portion, and sets the changeover switch 19 to D / D at the time of reproduction of the unrecorded portion and the overwritten portion.
The output is switched to the output SB of the A converter 20. Therefore, when the recording section is reproduced, the video signal demodulated by the demodulation circuit 15 as described above is supplied to the display device as it is.
At the time of reproducing the unrecorded portion and the overwritten portion, the video data read from the image memory 18 is converted into an analog video signal by the D / A converter 20, and then supplied to the display device. That is, at the time of reproducing the unrecorded portion and the overwritten portion, a video signal indicating a video cannot be obtained from the demodulation circuit 15 or cannot be obtained correctly. In particular, the image is disturbed in the overwriting portion, giving a sense of anxiety to the viewer. Therefore, in these portions, video signals are obtained from the image memory 18. When the unrecorded portion is reproduced, a track jump command signal may be supplied to the tracking servo circuit 23 so that the recorded portion can be immediately reached. Further, the microcomputer 37 causes the display 47 to display any reproduction state of the unrecorded portion, the recorded portion, and the overwritten portion according to the output levels of the comparison circuits 41 to 43.

After recording the video signal on the disk 2, the microcomputer 37 performs an additional recording operation when recording a video signal further. In the write-once recording operation, as shown in FIG. 7, first, the DC corresponding to the unrecorded portion, the recorded portion, and the overwritten portion is started from the innermost track of the disk 2.
The levels A, B, and C are held in the level holding circuits 38 to 40 (step S31). The operation in step S31 is the same as the operation in steps S11 to S20 described above.
Next, the pickup 1 is supplied to the slider drive circuit 46.
Is moved to the innermost track of the disk 2 (step S32). It is determined whether or not the pickup 1 has reached the innermost track (step S33).
When the pickup 1 reaches the innermost track, the switch 34 is turned off to open the tracking servo system (step S34), and the pickup 1 is moved from the innermost track to the outer track. A command is issued to the slider drive circuit 46 (step S35). At this time, the focus servo system including the differential amplifier 31, the focus servo circuit 32, the focus actuator 33, and the like operates.

While the pickup 1 is moving from the innermost track to the outermost track, the microcomputer 37 monitors the output level of the first comparison circuit 41 to detect an unrecorded portion (step S36). DC amplifier 3
If the output DC level of No. 5 is not equal to the level held in the level holding circuit 38 and the comparison circuit 41 outputs a low level indicating that the DC levels do not match, the process proceeds to step S35. On the other hand, the output DC level of the DC amplifier 35 is equal to the level held in the level holding circuit 38,
If the comparison circuit 41 outputs a high-level signal indicating a DC level match, the switch 34 is turned on to close the tracking servo system (step S37) because the reading position of the pickup 1 is in an unrecorded portion. , 1
A track jump command signal for advancing the track is generated (step S38).

Next, the switch 34 is turned off to open the tracking servo system (step S39), and the second comparison circuit 42 is used to detect the recording section.
Is monitored (step S40). If the output DC level of the DC amplifier 35 is not equal to the level held in the level holding circuit 39 and the comparison circuit 42 has a low level output indicating that the DC levels do not match, step S37
Move to On the other hand, if the output DC level of the DC amplifier 35 is equal to the level held in the level holding circuit 39 and the comparison circuit 42 has a high-level output indicating that the DC levels match, the reading position of the pickup 1 is in the recording unit. Therefore, the switch 34 is turned on to close the tracking servo system (step S41),
It is determined from the output of the sync separation circuit whether a horizontal sync signal or a vertical sync signal has been detected (step S42). When the synchronization signal is detected, the recording laser power is generated to instruct the start of the recording of the video signal (step S4).
3).

Thus, a new video signal can be partially overwritten on the recording portion and recorded in synchronization with the synchronization signal of the recording portion of the disk 2. Therefore, each video signal can be recorded without generating an unrecorded portion between the recording portion of the already recorded video signal and the recording portion of the new video signal. The additional recording in step S43 may be performed completely in synchronization with the boundary between the recorded portion and the unrecorded portion. In step S42, the occurrence of a pulse signal output from the rotation detector 50 instead of the horizontal synchronization signal or the vertical synchronization signal may be determined, and the additional recording may be started in synchronization with the pulse signal.

FIG. 8 shows the operation of the microcomputer 37 as another embodiment of the present invention. In this embodiment, it is determined whether or not a video signal is recorded instead of step S36 in FIG. 7 (step S5).
1). If the video signal exists, the process returns to step S35. If the video signal does not exist, the pickup 1
Is located in the unrecorded portion, so that step S3
7, the process proceeds to steps S38 and S39, and the switch 34 is turned on to close the tracking servo system.
A track jump command signal is generated to advance the track, and the switch 34 is turned off to open the tracking servo system. Next, step S4 in FIG.
It is determined whether a video signal is recorded instead of 0 (step S52). When there is no video signal, the process returns to step S37, and when there is a video signal, the process proceeds to step S41.

In steps S51 and S52, the presence of a video signal is detected in order to determine whether or not the reading position of the pickup 1 is an unrecorded portion. An unrecorded portion may be determined from a track crossing signal or the like. In each of the above-described embodiments, an unrecorded portion is located on the innermost track,
The recording part and the overwriting part were formed.
They may be formed in the A region. Further, the respective parts may be formed not only on the innermost track but also on another predetermined track on the disk.

[0029]

As the foregoing, in the optical disc apparatus of the present invention, the pickup is moved on the optical disk during the recording of the optical disk to be write-once recording information signals, and an output level of the pickup during the movement Level preservation
By comparison with the level held in the lifting means, the pickup is whether the one of the recording portion and the unrecorded portion on the optical disk is determined, the recording unit position pickup unrecorded portion immediately before in accordance with the determination result It is moved and the additional recording operation is started. As a result, additional recording is performed by overwriting the end of the recording section, so that an unrecorded section is prevented from occurring between the recording section of one information signal and the recording section of the next information signal. Therefore, a stable tracking operation can be obtained even on a disc on which additional recording has been performed and on a read-only optical disc apparatus having a three-beam tracking device. Further, in the optical disk device of the present invention,
The recorded information signal to be reproduced from the optical disc.
The pickup is moved on the optical disk at the time of
The output level of the pickup and its level
By comparing with the level held in the step, the pickup
Recorded, unrecorded, and overwritten parts on the optical disc
It is determined whether there is a shift, and the pick
If the up is in the recording area on the optical disk,
The recording information signal of the disk is output, and the pickup
If there is an unrecorded area on the
The video data stored in the memory means is output. this
When playing back unrecorded and overwritten parts,
However, the image can be prevented from being disturbed.

[Brief description of the drawings]

FIG. 1 is a diagram showing the amplitude of a tracking error signal by a three-beam method for a recorded portion and an unrecorded portion.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing an optical system of a pickup in the apparatus of FIG.

FIG. 4 is a diagram showing a light detection unit in the pickup of FIG. 3;

FIG. 5 is a flowchart showing the operation of a microcomputer in the apparatus of FIG. 2;

FIG. 6 is a flowchart showing the operation of the microcomputer in the apparatus shown in FIG. 2;

FIG. 7 is a flowchart showing the operation of the microcomputer in the apparatus of FIG. 2;

FIG. 8 is a flowchart showing the operation of the microcomputer in the apparatus of FIG. 2 as another embodiment of the present invention.

[Explanation of Signs of Main Parts]

 DESCRIPTION OF SYMBOLS 1 Pickup 2 Disk 15 Demodulation circuit 19 Changeover switch 37 Microcomputer 38-40 Level holding circuit 41-43 Comparison circuit 50 Rotation detector

Claims (2)

(57) [Claims] 1. A optical disk to record information signals there is provided an optical disk apparatus for reproducing the recorded information signal, a pickup for reading recorded signals of the optical de <br/> disk to write information signal and the optical disc And the pickup
Information on the optical disk when recording information signals.
Read from each of the recorded part and the unrecorded part
A level holding means for holding a level, is retained in the output level and the level holding means of the pick-up by moving the pickup on the optical disc during the recording onto the optical disc of the information signal to be additionally recorded Les
A determination unit that determines whether the pickup is in a recorded portion or an unrecorded portion on the optical disk by comparing the pickup with a bell; and determining whether the pickup is in accordance with a determination result of the determination portion. An optical disk device comprising: a driving unit that moves and drives the pickup so as to be positioned at the recording unit immediately before an unrecorded unit; and a unit that starts additional recording after the movement driving by the driving unit is completed. . 2. An information signal is recorded on an optical disk and recorded.
An optical disc device for reproducing an information signal, comprising:
Writing an information signal on a disk and recording the optical disk
A pickup for reading out signals, and the pickup
Information on the optical disk when recording information signals.
From each of the recorded, unrecorded, and overwritten sections
Level holding means for holding a level to be read;
Image memory means for storing data and recording to be reproduced
When the information signal is reproduced from the optical disk, the optical
Move the pickup on the disc to
Output level and the level held by the level holding means.
The pickup picks up the optical
Any of the recorded, unrecorded, and overwritten parts on the disk
Determination means for determining whether or not there is a
As a result, the pickup can record on the optical disc.
Output the recording information signal of the optical disk
To the recording side, the pickup is
In the recording section and the overwriting section, the image memory
Switch to the side that outputs the video data stored in the stage
Switching means, and an optical disk apparatus characterized by comprising:
Place.