JP2598249B2 - Optical disc playback device - 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 reproducing apparatus, and more particularly to an optical disk reproducing apparatus capable of reproducing both sides of an optical disk without reversing the optical disk mounted in the apparatus.

[0002]

2. Description of the Related Art In a conventional optical disk reproducing apparatus, for example, an apparatus for reproducing a laser vision disk (hereinafter referred to as an LD) on which video and audio information are recorded as an optical disk, an LD is mounted in the apparatus and the LD is mounted. Side 1 of
When reproducing the side 2 (the second surface) after reproducing the (first surface), once remove the mounted LD from the device, manually flip the LD, and then reinsert the LD in the device. It is necessary to perform the mounting operation, and it is necessary to perform a complicated operation such as the inversion of the LD and the operation of ejecting and mounting the LD.

[0003] It should be noted that as a device related to this type of device, for example, those described in JP-A-58-114354 and JP-A-58-114361 are listed.

[0004]

In the above-mentioned prior art, the optical disc mounted in the apparatus can be reproduced only from one side of the optical disc. However, a complicated operation of taking out the optical disk, inverting the optical disk, and mounting the optical disk in the apparatus again is necessary, and there is a problem in operability.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to play back both sides of an optical disk loaded in the apparatus without taking out and reversing the optical disk. It is an object of the present invention to provide an optical disk reproducing apparatus in which the objective lens of the head on the side that does not perform lowering due to its own weight causes a problem in performance.

[0006]

In order to achieve the above-mentioned object, according to the present invention, there is provided an optical disk having information signals recorded on both surfaces thereof, and an optical disk which is held at a holding portion thereof and driven at a predetermined rotation speed. An optical disk drive, and an optical head for reproducing an information signal recorded on the optical disk;

When the optical head mounts and holds the optical disk on a holding portion of the optical disk drive, the optical head reproduces a surface of the optical disk held by the holding portion as a first surface. If the first surface of the optical head and the first surface of the optical disk are the front surface, the surface corresponding to the back surface is the second surface.
And a second optical head for reproducing as a surface of
And

[0008] A bias applying means for applying a DC bias to an actuator for driving the objective lens of the second optical head in the focus direction to hold the objective lens at a position where it does not contact the optical disc.

Further, when the optical disk is mounted on and held by the holding portion of the optical disk drive, the fact is detected and the bias applying means is operated to bring the objective lens of the second optical head into contact with the optical disk. An optical disk mounting / holding detecting means for holding the optical disk at a position not in contact with the optical disk is provided. Alternatively, there is provided a power-on detecting means for detecting the fact when the power of the optical disk reproducing apparatus is turned on, operating the bias applying means, and holding the objective lens of the second optical head at a position not in contact with the optical disk. I decided that.

[0010]

According to the present invention, the first optical head and the second optical head are independently disposed near both sides of the optical disk. For example, the side 1 of the optical disk is the first optical head. The second optical head reproduces the data on the optical disk and the side 2 on the back surface of the side 1 by using the second optical head, thereby reproducing both surfaces of the optical disk while holding the optical disk in the optical disk drive. .

However, since the form of the signal tracks on the optical disc is predetermined, if the optical disc is rotated only in one direction, the first and second optical tracks are not rotated.
Can be reproduced by only one of the optical heads.

Therefore, according to the present invention, according to the form of the signal track on the optical disk, the optical disk drive unit performs the reproduction by the first optical head and the reproduction by the second optical head. Thus, the rotation direction of the optical disk is switched so that reproduction can be performed with any optical head. That is, when playing back with the first optical head, the optical disc is rotated in the first rotation direction to enable playback, and when playing back with the second optical head, the first optical head is used for playback. Reproduction is enabled by rotating in a second rotation direction opposite to the rotation direction.

When the optical disk is held by the optical disk drive, for example, the side 1 of the optical disk
If it is unclear whether it is on the first optical head side or on the second optical head side, it is first reproduced by either one of the two optical heads, Since the side signal can be detected from the address information section of the optical disk, it is possible to determine which optical head the side 1 of the optical disk is on the basis of the side signal. Therefore, it is possible to correctly reproduce the surface specified by the user by determining whether to reproduce with the first optical head or with the second optical head based on the determination result.

Further, when the optical disk is mounted on and held by a holder of the optical disk drive, a first surface for reproducing a surface of the optical disk held by the holder as a first surface. An optical head and a first optical disk.
When the information signal is reproduced by the second optical head among the second optical head for reproducing the surface corresponding to the rear surface as the second surface, In the first optical head, since the objective lens in the first optical head is not driven by the focus actuator, the objective lens may be lowered by its own weight, causing a problem in performance. In such a case, by applying a DC bias to the focus actuator of the first optical head and holding the objective lens at a predetermined position, it is possible to prevent the occurrence of inconvenience in performance. it can.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an optical disk reproducing apparatus as one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes each recording area 2a, 3a
Ordinary optical disk (laser vision disk) constructed by bonding single disks 2 and 3 each having
Numeral denotes an optical disk drive for rotating and driving the optical disk 1. The optical disk drive includes a disk motor 11, a rotation speed detector 12, a turntable 13, a center adapter 14, a clamper 15, and the like.

Reference numeral 16 denotes a disk motor drive circuit, 2
Reference numeral 0 denotes a first optical head having an objective lens 21, 25 denotes a first slider holding the first optical head 20, 26 denotes a first slider motor, 27 denotes a first drive circuit, and 30 denotes an objective lens. A second optical head with 31;
The second slider holding the optical head 30 of the second
Is a second drive circuit.

In addition, 50 is a system control unit, 51 is a laser drive circuit, 52 is a focus / tracking control circuit, 53 is a switching control circuit, and 54 is a device for operating the objective lens 31 of the second optical head 30 in the focus direction. Focus operation circuit 55, each optical head 2
A detection signal processing circuit for processing detection signals from 0 and 30; 56, a reproduction signal processing circuit; 57, an address information processing circuit;
Reference numeral 00 denotes an optical disk reproducing device.

Next, the operation will be described. First, the configuration of the optical disc 1 and a method of double-sided reproduction thereof will be described with reference to FIGS.

FIG. 2 is a sectional view showing a section of an arbitrary signal track on the optical disk of FIG. 1, and FIG. 3 is an explanatory view showing the form of signal tracks on the upper and lower surfaces of the optical disk of FIG.

As shown in FIG. 2, an optical disk 1, which is a laser vision disk on which video and audio signals are recorded, first is a single disk of transparent plastic (usually acrylic resin) (hereinafter, a single-plate disk). Say.)
Information signals are formed as spiral tracks 2e, 3e on one surface of the two or three in the form of concavo-convex pits 2b, 3b, and the surfaces thereof are coated with metal thin films 2c, 3c to form a reflective film. Are coated with protective films 2d and 3d made of resin, and thereafter, the single-plate disks 2 and 3 are bonded to each other with an adhesive layer 5 so that the information signal surface is located inside. .

In the single-plate disks 2 and 3, the direction of the spiral tracks 2e and 3e on which information signals are recorded (however, recording of information signals is performed from the inner circumference to the outer circumference) is each single. It is the same on the plate-shaped disks 2 and 3, but the optical disk 1 is attached so that the information signal surfaces of the optical disks 1 are located inside, so that the optical disk 1 is moved from one direction (for example, from the top surface direction). When viewed, the spiral tracks 2 on the single-plate disks 2 and 3
The directions of e and 3e are opposite to each other.

That is, when the optical disc 1 is observed from above, the direction of the spiral track 2e formed on the lower single-plate disc 2 shown in FIG. 3A and the upper track shown in FIG. Spiral track 3e formed on single-plate disk 3
Are opposite to each other.

Accordingly, the spiral track 2e of the single-plate disk 2 shown in FIG. 3A is not shown in the first optical head 20 (FIG. 3A), but provided below. When reproducing the light spot 22 from the optical head 20 by a dotted line), the information signal can be reproduced by rotating the optical disc 1 in the direction of arrow X in the figure, and FIG.
The spiral track 3e of the single-plate disk 3 shown in FIG.
Is reproduced by a second optical head 30 (not shown in FIG. 3B, but a light spot 32 from the second optical head 30 is indicated by a solid line) disposed above.
Must be driven to rotate in the direction of the arrow Y in the figure.

That is, in this embodiment, independent optical heads 20 and 30 are provided on the upper and lower surfaces of the optical disc 1 mounted in the optical disc reproducing apparatus 100, and the optical disc 1 is controlled by controlling the rotation drive of the optical disc 1. This allows both sides of the optical disc 1 to be reproduced without being taken out and inverted.

Next, the operation of this embodiment will be described in more detail with reference to FIG. In FIG. 1, first, an optical disk 1 is moved to a predetermined position in an optical disk reproducing apparatus 100 by a loading mechanism (not shown),
It is positioned on the center turntable 13 by the center adapter 14 and is fixedly held by the clamper 15. Here, the side 1 of the optical disc 1 is the lower surface (the surface of the recording area 2a recorded on the single-plate disc 2),
The side 2 will be described as the upper surface (the surface of the recording area 3a recorded on the single-plate disk 3).

Therefore, when a user performs a predetermined operation (for example, a play operation or the like) from an operation button (not shown) or a remote controller (not shown) of the optical disk reproducing apparatus 100, the reproducing operation mode signal 60 is generated. The data is input to the system control unit 50. As a result, a control signal 61 is output from the system control unit 50 to operate the disk motor drive circuit 16 and output a drive signal 62
Drives the disk motor 11 of the optical disk drive 10.

At this time, the rotation speed of the disk motor 11 is detected by a rotation speed detector 12 (FG: frequency generator, etc.), and the output of the rotation speed detection signal 63 is input to the disk motor drive circuit 16 for feedback. By performing the control and the like, the disk motor 11, that is, the optical disk 1 can be rotated at a predetermined rotation speed.

A control signal 66 is also output from the system control unit 50 to operate the laser drive circuit 51, and a laser drive signal 67 from the laser drive circuit 51 is input to the switching control circuit 53. At this time, the switching control circuit 5
3 controls the first optical head 20 to be driven as an initial setting by the drive signal 65 from the system control unit 50 (the switching units 53a, 5a of the switching control circuit 53).
3b is ON), the laser drive signal 67 is input to the first optical head 20 as the signal 67a via the switching section 53a of the switching control circuit 53.

Further, a drive signal 80 is output from the system control section 50 to drive the focus / tracking control circuit 52, and a control signal 72, which is an output of the drive signal 80, is transmitted to the switching control circuit 53 similarly to the case of the laser drive signal 67. The control signal 73 is input to the first optical head 20 via the switching unit 53b. Then, in the first optical head 20, the well-known optical system and the objective lens 21 are driven in the focus and tracking directions (X and Y directions in the drawing) by the operation of an actuator or the like, and the first optical head 2
A light beam from 0 is irradiated as a small spot on a predetermined track of the recording area 2a of the single-plate disk 2 below the optical disk 1 to enable detection of an information signal.

The information of the recording area 2a detected by the first optical head 20 is input to the detection signal processing circuit 55 as a detection signal 69, and one of its outputs is a signal 71 (focus / tracking error signal). ) Is input to the focus / tracking control circuit 52, and performs feedback control so that a minute spot can be appropriately irradiated on a predetermined track even if there is surface deflection, eccentricity, or the like caused by rotation driving of the optical disc 1. Another signal 76 from the detection signal processing circuit 55 is input to the reproduction signal processing circuit 56 and becomes an output signal 77 for video and audio, and video and audio are reproduced on a TV or the like.

Further, another signal 78 from the detection signal processing circuit 55 is input to the address information processing circuit 57, and together with the address information, a side signal (side 1 / side 2) and a disk format signal (CAV / CL).
V) and the like are input to the system control unit 50 as the detection signal 79.

The signal 64 from the system control unit 50 is input to the first drive circuit 27, and the output thereof drives the first slider motor 26. The irradiation position of the minute spot irradiated on the optical disc 1 from 20 is always the first position.
The first slider 25 that holds the first optical head 20 so as to come to a position directly above the center of the optical head 20
Is moved in the radial direction of the optical disc 1.

As described above, when the reproduction operation mode signal 60 is input to the system control unit 50, the system control unit 50 drives the disk motor drive circuit 16 to drive the optical disk held by the optical disk drive unit 10. The laser drive circuit 51 and the focus / tracking control circuit 52
Is driven, the switching control circuit 53 is set to a predetermined state, and the laser drive signal 67 and the control signal 72 are input to the first optical head 20, whereby the single-plate disk below the optical disk 1 is Thus, it is possible to reproduce the recording area 2a on the side 1 of No. 2.

When the first optical head 20 reproduces the side 1 of the optical disk 1, the objective lens 21 of the first optical head 20 is subjected to the well-known focus / tracking control as described above. Is the second optical head 30
Since the objective lens 31 is not particularly controlled, the objective lens 31 of the second optical head 30 may move in the direction of gravity due to its own weight, which may cause inconvenience in performance.

Therefore, in the present embodiment, when the control signal 72 is input to the first optical head 20 by the switching control circuit 53, the focus operation circuit 54 is driven by the control signal 75 and a predetermined DC bias is applied. By supplying 74 (current or the like) from the focus operation circuit 54 to the second optical head 30, the objective lens 31 of the second optical head 30
At a predetermined position that does not come into contact with the optical disc 1.

Now, as described above, the first optical head 2
0 reproduces the side 1 of the optical disc 1 for a predetermined time,
When reproducing to the final recording position of the side 1, the first optical head 20 detects a lead-out signal recorded in advance in the recording area 2a of the optical disk 1, and notifies the address information processing circuit 57 that the reproduction of the side 1 has been completed. To the system control unit 50 via

Therefore, the system control unit 50
The optical disk 1 is driven to rotate in the opposite direction (counterclockwise direction) to the rotational direction of the optical disk 1 when the side 1 of the optical disk 1 was being reproduced (set in the timewise direction by initial setting). Then, the control signal 61 is input to the disk motor drive circuit 16. Accordingly, the disk motor drive circuit 16 controls the disk motor 11 of the optical disk drive unit 10 to rotate the optical disk 1 in a counterclockwise direction at a predetermined rotation speed.

Further, the system control unit 50
By outputting the drive signal 65 and controlling the switching of the switching sections 53a and 53b of the switching control circuit 53 (in a state where the switching sections 53a and 53b are ON), the laser driving signal 67 from the laser driving circuit 51 is output. Is input to the second optical head 30 as a signal 67b, and a control signal 72 from the focus / tracking control circuit 52 is a control signal 74
Is input to the second optical head 30.

The objective lens 3 of the second optical head 30
In order to hold 1 at a predetermined position in the focus direction, the control signal output from the focus operation circuit 54 is automatically turned off when the switching unit 53b of the switching control circuit 53 switches.

Next, the laser drive unit signal 67 and the control signal 74 for controlling the objective lens 31 in the focus / tracking direction are input to the second optical head 30, whereby the second optical head 30 The light beam is
Side 2 of single-plate disc 3 above optical disc 1
The recording area 3a on which the information is recorded is appropriately irradiated as a minute spot.

Then, the information of the recording area 2a detected by the second optical head 30 is input to the detection signal processing circuit 55 as a detection signal 70, and the first optical head 2
As in the case of 0, the signal 71 is sent to the focus / tracking control circuit 52, the signal 76 is sent to the TV or the like as the output signal 77 of video and audio via the reproduction signal processing circuit 56,
At the same time, the signal 78 is input to the system control unit 50 as a signal 79 containing address information and the like via the address information processing circuit 57, and the side 2 of the optical disk 1 can be reproduced.

As described above, in the present embodiment, first, the optical disc 1 is rotationally driven in a predetermined direction (time rotation direction),
The optical head 20 reproduces the side 1 of the optical disc 1,
By detecting the end of reproduction of the side 1 (that is, detecting the lead-out signal), the optical disk 1 is driven to rotate in the reverse direction (counterclockwise) and switched to be reproduced by the second optical head 30. The side 2 of the optical disk 1 is continuously reproduced by the second optical head 30, so that both-side reproduction of the optical disk 1 becomes possible.

Next, referring to FIG. 4, the operation state of the main part in FIG. 1 will be described again. FIG. 4 is an explanatory diagram for explaining an operation state of a main part in FIG. That is, when inserting the optical disc 1 into the optical disc reproducing apparatus 100,
The focus operation circuit 54 applies a minute DC bias as the control signal 74 to the second optical head 30 so as to hold the objective lens 31 at a predetermined position, as shown in FIG.

The level of the DC bias is set to a drive voltage of 0.4 V in the current configuration of the actuator in the optical head (for example, a configuration in which a drive current is supplied to a drive coil to magnetically drive an objective lens). Drive current about 3
At about 0 mA, the objective lens can be raised by about 4 mm, and the contact with the optical disc 1 can be sufficiently prevented. The power consumption is as small as about 12 mW, and there is no problem even if the power is supplied for a long time.

The application of the DC bias to the second optical head 30 may be started at any time other than when the optical disk 1 is inserted as described above.
It may be at the time of N or at the start of various operations such as the start of a play operation (there is no particular problem even if the optical disk 1 is in contact if it is not rotating).

When the optical disc 1 is mounted at a predetermined position of the optical disc reproducing apparatus 100, a drive signal 62 is then supplied to the optical disc drive 10 as shown in FIG. Is turned on so as to rotate the optical disk 1 in a predetermined direction (clockwise direction). As a result, as shown in FIG. 4B, the rotation input from the rotation speed detector 12 to the disk motor drive circuit 16 is performed. The number detection signal 63 is similarly turned on. Then, the control signal 73 input to the first optical head 20 is
In the N state, the side 1 of the optical disk 1 is reproduced. At this time, the second optical head 30 is in a state where a minute DC bias is applied as the control signal 74.

Next, when the reproduction of the information on the side 1 of the optical disk 1 is completed, the drive signal 62 to the optical disk drive unit 10 is turned on in the opposite direction, and the rotational speed detection signal 63 input to the disk motor drive circuit 16 Is also controlled to the reverse rotation state. Then, the control signal 73 input to the first optical head 20 is turned off, the control signal 74 input to the second optical head 30 is turned on, and the side 2 of the optical disc 1 can be reproduced.

Further, when the reproduction of the side 2 of the optical disk 1 is completed, the optical disk 1 is ejected by an ejecting operation,
Then, when the ejection operation of the optical disc 1 is completed, the second
The DC bias application to the optical head 30 is also turned off. Note that, as described above, the second optical head 30
Is stopped when the optical disk reproducing apparatus 100 is turned off, in addition to when the optical disk 1 is ejected.
Alternatively, the rotation of the optical disc 1 may be stopped.

In the above description, when the optical disk 1 is mounted on the optical disk reproducing apparatus 100, the side 1 of the optical disk 1 is set to be the lower surface. However, the side 2 of the optical disk 1 is set to be the lower surface. , Continuous playback from side 1 to side 2 of the optical disc 1 is possible.

The operation in that case will be described with reference to FIG. FIG. 5 is an explanatory diagram for describing an operation state in a case different from FIG.

The optical disk 1 is set in the optical disk reproducing apparatus 100.
Is mounted in an arbitrary state (that is, an arbitrary side surface of the optical disk 1 is set as a lower surface) (however, a case where the side 1 of the optical disk 1 is a lower surface is apparent from the above description; 1 will be described as a state in which the side 2 is a lower surface.) However, as an initial setting state, as in the past, the disk motor 11 rotates clockwise as shown in FIG. Then, the drive signal 62 to the disk drive unit 10 is turned on, and as a result, the detection signal 63 to the disk motor drive circuit 16 is clockwise as shown in FIG. 5B.

Further, the control signal 73 to the first optical head 20 is turned on as an initial setting state, so that the lower surface of the optical disc 1 is reproduced by the first optical head 20, and To detect the side surface of the optical disk 1. As a result, it can be determined that the lower surface of the optical disk 1 is the side 2, and it is understood that the side 1 of the optical disk 1 is above the optical disk 1.

Therefore, the system control unit 50
Drive signal 6 output from disk motor drive circuit 16
2 is turned on as shown in FIG. 5A, and the optical disk drive unit 10 is controlled to perform reverse rotation (counterclockwise) drive. Therefore, the rotation number detection signal 63 input to the disk motor drive circuit 16 is in a counterclockwise direction, and the control signal 74 to the second optical head 30 is turned ON, so that the upper side of the optical disk 1 A certain side 1 can be reproduced.

When the reproduction of the side 1 of the optical disk 1 is completed by the second optical head 30, the optical disk drive unit 10 switches the drive signal 62 so as to drive the optical disk 1 clockwise. As a result, the rotation number detection signal 63 input to the disk motor drive circuit 16 is in a clockwise direction, and the control signal 73 to the first optical head 20 is turned on, so that the optical disk 1
Side 2 can be reproduced.

That is, even if the optical disk 1 is mounted in an arbitrary state (an arbitrary side surface of the optical disk 1 is set as a lower surface), first, the initial setting operation detects which side surface the lower surface of the optical disk 1 is. Then, based on the detection result, the optical disk 1 and the optical heads 20 and 30 are reproduced such that the side 1 of the optical disk 1 is reproduced first.
Is controlled.

As an initial setting operation, as described above, the optical disc 1 is driven to rotate clockwise and detected by the first optical head 20, or conversely, the optical disc 1 is rotated counterclockwise. There is no problem in both cases, in which the second optical head 30 is driven to rotate in the rotation direction and the detection is performed by the second optical head 30.

In this embodiment, as the reproduction order of the optical disc 1, the side 1 is reproduced first, and then the side 2 is reproduced.
Has been described as a double-sided reproduction method. For example, when the user wants to reproduce the side 2 first, the user designates a desired side surface (in this case, side 2) with a predetermined operation button, and performs system control. By performing a predetermined control operation by the unit 50, it is of course possible to reproduce from the side 2 first.

[0059]

As described above, according to the present invention, the first optical head and the second optical head are independently disposed in the vicinity of each of both surfaces of the optical disk mounted in the apparatus. Therefore, for example, by reproducing the side 1 of the optical disk with the first optical head and the side 2 with the second optical head, both sides of the optical disk are reproduced with the optical disk mounted. be able to. Therefore, there is no need to perform a complicated operation such as taking out the mounted optical disk once, turning over the optical disk, and mounting the optical disk again as in the related art.

In the case where the reproduction is started by one of the first and second optical heads for the time being and the side signal recorded on the optical disk is detected, the optical disk may be an arbitrary one. Even if it is mounted in a state, it is possible to reproduce the side surface desired by the user based on the detected side signal, and it is possible to provide an easy-to-use optical disk reproducing apparatus.

Further, since the optical disk is held by the holding portion of the optical disk driving portion, the first and second optical heads are located near the surface of the optical disk on the side held by the holding portion. When the information signal is reproduced by the optical head disposed on the other side, the objective lens is not driven by the focus actuator in the other optical head on the side not reproducing the information signal. May be lowered in the direction of gravity due to its own weight, which may cause inconvenience in the performance of the optical disk reproducing apparatus. However, in the present invention, the DC bias is applied to the focus actuator of the optical head which is not reproducing the information signal. Is applied to hold the objective lens at a predetermined position, it is possible to prevent the occurrence of inconvenience in performance of the optical disk reproducing apparatus.

[0062]

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a sectional view showing a section of an arbitrary signal track on the optical disc of FIG. 1;

FIG. 3 is an explanatory diagram showing the form of signal tracks on the upper and lower surfaces of the optical disc of FIG. 1;

FIG. 4 is an explanatory diagram for explaining an operation state of a main part in FIG. 1;

FIG. 5 is an explanatory diagram for explaining an operation state of a main part in FIG. 1;

[Explanation of symbols]

1 ... optical disk, 2,3 ... single plate disk, 10 ...
... Optical disk drive unit, 20 ... first optical head, 30 ...
... second optical head, 50 ... system control unit,
53: switching control circuit, 54: focus operation circuit,
100 ... optical disc reproducing apparatus.

Claims (3)

(57) [Claims] An optical disk having information signals recorded on both sides thereof; an optical disk drive for holding the optical disk in a holder thereof and driving the optical disk at a predetermined rotation speed; and an information signal recorded on the optical disk. An optical disk reproducing device comprising: an optical head for reproducing the optical disk; wherein the optical head is mounted on the holding unit of the optical disk driving unit, and when the optical disk is held, the optical disk is held by the holding unit. A first optical head for reproducing the surface of the optical disk as a first surface, and a second optical head for reproducing the surface of the optical disk as a second surface if the first surface is the front surface. And the second
A bias applying means for applying a DC bias to an actuator for driving the objective lens of the optical head in the focusing direction, and holding the objective lens at a position where the objective lens does not contact the optical disk. . 2. An optical disc having information signals recorded on both sides thereof, an optical disc driving section for holding the optical disc in a holding section and driving the optical disc at a predetermined number of rotations, and an information signal recorded on the optical disc. An optical disk reproducing device comprising: an optical head for reproducing the optical disk; wherein the optical head is mounted on the holding unit of the optical disk driving unit, and when the optical disk is held, the optical disk is held by the holding unit. A first optical head for reproducing the surface of the optical disk as a first surface, and a second optical head for reproducing the surface of the optical disk as a second surface if the first surface is the front surface. And the second
Bias applying means for applying a DC bias to an actuator for driving the objective lens of the optical head in the focusing direction to hold the objective lens at a position where the objective lens does not come into contact with the optical disc; And mounting / detecting means for detecting the fact and operating the bias applying means when holding and holding the objective lens of the second optical head at a position not in contact with the optical disk. An optical disc reproducing apparatus characterized by the above-mentioned. 3. An optical disk having information signals recorded on both sides thereof, an optical disk drive for holding the optical disk in a holder and driving the optical disk at a predetermined number of revolutions, and an information signal recorded on the optical disk. An optical disk reproducing device comprising: an optical head for reproducing the optical disk; wherein the optical head is mounted on the holding unit of the optical disk driving unit, and when the optical disk is held, the optical disk is held by the holding unit. A first optical head for reproducing the surface of the optical disk as a first surface, and a second optical head for reproducing the surface of the optical disk as a second surface if the first surface is the front surface. And the second
Bias applying means for applying a DC bias to an actuator for driving the objective lens of the optical head in the focus direction to hold the objective lens at a position where the objective lens does not come into contact with the optical disk; An optical disk reproducing device, comprising: a power-on detecting unit for detecting the fact that the bias applying unit is operated to hold the objective lens of the second optical head at a position where the objective lens does not contact the optical disk.