JPH08241566A - Optical disk device - Google Patents

Abstract

PURPOSE: To provide an optical disk device capable of automatically discriminating between a disk having an information surface on one side and the disk having the information surfaces on both sides. CONSTITUTION: In the state that the disk 31 is loaded on a turntable 43, the presence of the information surface on a reproducing surface of a pickup 32 is detected by an output of a focusing decision circuit 46, and the presence of the information surface and a protection layer of the surface opposite to the reproducing surface of the pickup 32 are detected with a photodetector 48 by reflected light of light from a light source 47. Thus, whether the disk having the information surface only on one side or the disk having the information surfaces on both sides is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc type determination which can record or reproduce a plurality of types of optical discs by an optical disc device such as a digital video disc player.

[0002]

2. Description of the Related Art In recent years, optical disc devices for reproducing optical discs such as digital video discs and compact discs capable of recording audio and video signals have become popular for home use. In particular, optical discs have a protective layer thickness of 1.2 mm, which is typical of compact discs, and single-sided recording, and digital video discs have a protective layer thickness of 0.6 mm, which is double-sided. There are some. Since these two types of optical discs have different signal recording systems, they cannot be handled by the same signal processing circuit and rotation control circuit, and it is necessary to switch between two types of signal processing circuits and rotation control circuits. . In the future, it is desired to realize such an optical disc device that can automatically determine which optical disc is used for recording and reproduction.

The above-mentioned conventional optical disc device will be described below with reference to the drawings. FIG. 14 shows a block diagram of a conventional optical disc device.

In FIG. 14, reference numeral 1 denotes a disc on which video information, audio information and the like are recorded. As will be described later, the disc 1 includes a first type disc and a second type disc, which are recorded in different signal formats. Reference numeral 2 is a pickup, which converts the information on the disk 1 into an electric signal. A pickup control circuit 3 controls the pickup 2 so that the focus of the pickup 2 follows the information track of the disc 1. 4 is the first switch,
The information read by the pickup 2 is switched and output to the first demodulation circuit 5 or the second demodulation circuit 6. Reference numeral 5 denotes a first demodulation circuit, which performs signal demodulation of the first type disk. A second demodulation circuit 6 demodulates the signal of the second type disk. A second switch 7 switches between the output of the first demodulation circuit 5 and the output of the second demodulation circuit 6 for output. An output terminal 8 outputs the output of the second switch 7 from this. A third switch 9 switches the outputs of the first spindle drive circuit 10 and the second spindle drive circuit 11 to change the spindle motor 1
Output to 2. Reference numeral 10 denotes a first spindle drive circuit, which generates a spindle motor drive signal when reproducing a first type disc. Reference numeral 11 denotes a second spindle drive circuit, which generates a spindle motor drive signal when reproducing a second type disc. A spindle motor 12 is driven by the output of the third switch 9. Reference numeral 13 is a turntable on which the disc 1 is mounted. A switch selection circuit 14 switches the first switch 4, the second switch 7, and the third switch 9 by the input from the operation switch 15. Reference numeral 15 denotes an operation switch, which has a button with which the user can instruct the type of disc.

FIG. 15 is a diagram showing a cross section of a first type disk reproduced by a conventional optical disc device.

In FIG. 15, reference numeral 21 is a label,
This is for protecting the back surface of the information surface 22 and for displaying and printing the information content. Reference numeral 22 denotes an information surface, on which information is recorded by the unevenness of the information track formed in a spiral shape. Two
A protective layer 3 has a thickness of 1.2 mm and is for protecting the information surface.

FIG. 16 is a view showing a cross section of a second type disk reproduced by the conventional optical disk device.

In FIG. 16, reference numeral 25 is a second information surface, on which information is recorded by the unevenness of the spirally formed information track. 24 is the second surface protective layer, and is 0.6
It has a thickness of mm and is for protecting the second information surface 25. Reference numeral 27 denotes a first side information surface, on which information is recorded by the unevenness of the information track formed in a spiral shape.
26 is a first surface protection layer, having a thickness of 0.6 mm,
The first information surface 27 is for protecting the information surface.

The operation of the conventional optical disc device constructed as described above will be described below.

As shown in FIG. 15, the first type disc has information recorded on one side, and the second type disc has information recorded on both sides as shown in FIG.
Both the first type disc and the second type disc,
Information is recorded by the unevenness of the information track formed in a spiral shape on the reflection surface, but the first type of disc mainly has a relatively low recording density for recording audio signals and high compression rate moving image signals. The second type of disk is a disk having a relatively high recording density mainly for recording a low compression rate moving image signal. Therefore, the recording method is different between the first type disc and the second type disc,
It is necessary to rotate the disk at different rotation speeds and demodulate with different demodulation circuits.

In FIG. 14, the user preliminarily indicates the type of the disc to be reproduced by the operation switch 15. The operation switch 15 is provided with two buttons, and by pressing the buttons, the first type disc and the second type disc are selected. Operation switch 1
The output of 5 is input to the switch selection circuit 14. The switch selection circuit 14 receives the first switch 4,
The second switch 7 and the third switch 9 are switched. That is, when the instruction of the operation switch 15 is the disk of the first type, the first switch 4, the second switch 7, and the third switch 9 are respectively switched to the a side, and the operation switch 1
If the instruction of 5 is for the second type of disk, the first switch 4, the second switch 7, and the third switch 9 are switched to the b side.

The disk 1 is rotated by a spindle motor 12. The pickup 2 converts the information recorded on the disc 1 into an electrical signal and outputs it. The pickup control circuit 3 causes the optical beam focus of the pickup 2 to correctly follow the information track recorded on the disc 1.
Control the pickup 2. Information of the disc 1 converted into an electric signal by the pickup 2 is stored in the first switch 4
Is input to As described above, the first switch 4 is set to the a side in the case of the first type disk and to the b side in the case of the second type disk by the switch selection circuit 14. Therefore, the information of the disc 1 converted into an electric signal is sent to the first demodulation circuit 5 when the disc of the first type is instructed and to the second information when the disc of the second type is instructed. It is input to the demodulation circuit 6.
The first demodulation circuit 5 is a circuit for demodulating the first type disc, and demodulates the input signal and outputs a video / audio signal. The second demodulation circuit 6 is a circuit for demodulating the second type of disc, and demodulates the input signal and outputs a video / audio signal. The first type disc is the first demodulation circuit 5
The second type disc can be demodulated only by the second demodulation circuit 6. The second type disc cannot be demodulated by the first demodulation circuit 5 or the first type disc cannot be demodulated by the second demodulation circuit 6. As described above, the second switch 7 is set to the a side in the case of the first type disk and to the b side in the case of the second type disk by the switch selection circuit 14. Therefore, when the disc of the first type is designated, the first demodulation circuit 5
The output of the second demodulation circuit 6 is output from the output terminal 8 through the second switch 7 when the second type disc is instructed. As described above, the third switch 9 is set to the a side by the switch selection circuit 14 in the case of the first type disk and the b side in the case of the second type disk. Therefore, when the first type disk is designated, the output of the first spindle drive circuit 10 is output, and when the second type disk is designated, the output of the second spindle drive circuit 11 is the first. It is input to the spindle motor 12 through the switch 9 of 3. The first spindle drive circuit 10 is a circuit for driving the spindle motor 12 at a rotation speed suitable for demodulating the first type disk, and the second spindle drive circuit 11
Is a circuit for driving the spindle motor 12 at a rotation speed suitable for demodulation of the second type disk. The optimum rotation speed is different between the first type disc and the second type disc. The first type disk can be demodulated by the first demodulation circuit 5 only when rotated by the first spindle drive circuit 10.
The second type disk is the second spindle drive circuit 11
It can be demodulated by the second demodulation circuit 6 only when rotated by. The second kind of disk is connected to the first spindle drive circuit 10
It is impossible to demodulate even if the first type disk is rotated by the second spindle drive circuit 11. Therefore, the spindle motor 12 receives the first
In the case of the disc of the type 1 and the type 2 of the disc, the turntable 1 is rotated at a rotation speed suitable for information reproduction.
Rotate 3. The disc 1 is mounted on the turntable 13, and when the turntable 13 rotates, the disc 1 also rotates.

[0013]

However, in the optical disc device having such a structure, the user needs to instruct the type of the disc by the operation switch, which gives the user a feeling of complication and the user. There is a problem that does not work properly if the instruction is wrong.

The present invention solves the above-mentioned conventional problems, and provides an optical disc device which does not require the user to indicate the disc type by an operation switch by automating the disc type discrimination. The purpose is to

[0015]

In order to achieve this object, an optical disc apparatus of the present invention comprises a pickup for reading or writing information recorded on the optical disc.
The optical disc pickup has a configuration including a detection means for detecting the presence or absence of an information recording surface opposite to the surface from which information is read or written, and the detection means is an optical information recording surface. It is to detect the reflection from the.

[0016]

With this configuration, the pickup detects the presence or absence of the information recording surface on the opposite side of the surface from which information is read or written, and thus the disc has an information surface on only one side or has an information surface on both sides. It is possible to determine whether the disc is a disc, and by automating the discrimination of the disc type, it is possible to provide an optical disc device that does not require the user to indicate the disc type by the operation switch.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disc device according to a first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an optical disk device according to a first embodiment of the present invention. In FIG. 1, reference numeral 31 denotes a disc on which video information, audio information and the like are recorded. As will be described later, the disc 31 includes a first type disc and a second type disc, which are recorded in different signal formats. Reference numeral 32 denotes a pickup, which converts information on the disc 31 into an electric signal. A pickup control circuit 33 controls the pickup 32 so that the focus of the pickup 32 follows the information track of the disc 31.
A first switch 34 switches the information read by the pickup 32 and outputs the information to the first demodulation circuit 35 or the second demodulation circuit 36. Reference numeral 35 is a first demodulation circuit, which performs signal demodulation of the first type disk. Reference numeral 36 is a second demodulation circuit, which performs signal demodulation of the second type of disk. A second switch 37 switches between the output of the first demodulation circuit 35 and the output of the second demodulation circuit 36 for output. 38 is an output terminal, and the second switch 37
The output of is output from this. Reference numeral 39 denotes a third switch, which switches the outputs of the first spindle drive circuit 40 and the second spindle drive circuit 41 to change the spindle motor 42.
Output to. 40 is a first spindle drive circuit,
A spindle motor drive signal is generated when reproducing the first type disc. Reference numeral 41 denotes a second spindle drive circuit, which generates a spindle motor drive signal when reproducing a second type disc. A spindle motor 42 is driven by the output of the third switch 39.
Reference numeral 43 is a turntable on which the disc 31 is mounted. Reference numeral 44 denotes a switch selection circuit, which receives the first switch 34, the second switch
The switch 37 and the third switch 39 are switched. Four
A disc discriminating circuit 5 discriminates the disc from the output of the focus discriminating circuit 46 and the input of the photodetector 48, and gives an instruction to the switch selecting circuit 44. Reference numeral 46 is a focus determination circuit,
It is detected whether or not the optical beam focus of the pickup 32 is correctly focused on the information surface of the disc 31, and the result is output to the disc discrimination circuit 45. Reference numeral 47 denotes a light source, which obliquely irradiates the surface of the disc 31 opposite to the reproduction surface of the pickup 32. Reference numeral 48 denotes a photodetector, which detects the presence or absence of light emitted from the light source 47 reflected by the disc 31, and outputs the result to the disc discrimination circuit 45.

FIG. 2 is a diagram showing a cross section of a first type disk reproduced by the optical disc apparatus of the first embodiment of the present invention.

In FIG. 2, reference numeral 71 is a label for protecting the back surface of the information surface 72 and for displaying and printing the information content. Reference numeral 72 denotes an information surface, on which information is recorded by the unevenness of the information track formed in a spiral shape. A protective layer 73 has a thickness of 1.2 mm and is for protecting the information surface.

FIG. 3 is a diagram showing a cross section of a second type disk reproduced by the optical recording apparatus of the first embodiment of the present invention.

In FIG. 3, 74 is a second surface protective layer,
It has a thickness of 0.6 mm and is for protecting the second information surface 75. Reference numeral 75 denotes a second surface information surface, on which information is recorded by the unevenness of the information track formed in a spiral shape. The first surface protection layer 76 has a thickness of 0.6 mm and is for protecting the first information surface 77 information surface. Reference numeral 77 denotes a first surface information surface, on which information is recorded by the unevenness of the information track formed in a spiral shape.

FIG. 4 is a diagram showing the operation of the photodetector when the disk of the first type is mounted on the optical disk device of the first embodiment of the present invention.

FIG. 5 is a diagram showing the operation of the photodetector when the second type disk is mounted on the optical disk device of the first embodiment of the present invention.

The operation of the video signal reproducing apparatus of the first embodiment of the present invention constructed as above will be described below.

As shown in FIG. 2, the first type disc has information recorded on one side, and the second type disc has information recorded on both sides as shown in FIG. In both the first type disc and the second type disc, information is recorded by the unevenness of the information track spirally formed on the reflecting surface. However, the first type disc mainly records audio signals, The second type of disc is a relatively low recording density disc for recording a high compression rate moving image signal.
It is a disk with a relatively high recording density mainly for recording low compression rate moving image signals. Therefore, the first type disc and the second type disc have different recording methods, and it is necessary to rotate the discs at different rotation speeds and to demodulate by different demodulation circuits.

The pickup 32 converts the information recorded on the disc 31 into an electrical signal and outputs it. The pickup control circuit 33 controls the pickup 32 so that the optical beam focus of the pickup 32 correctly follows the information track recorded on the disc 31. The focus determination circuit 46 sends a detection signal to the disc determination circuit 45 when it detects that the optical beam focus of the pickup 32 is correctly focused on the information surface of the disc 31. That is, the focus determination circuit 4
The output of 6 indicates the presence or absence of the information surface of the reproduction surface of the pickup 32 of the disc 31. The light source 47 obliquely emits light to the surface of the disc 31 opposite to the reproduction surface of the pickup 32. The photodetector 48 detects the presence or absence of light emitted from the light source 47 reflected by the disc 31, and outputs it to the disc discrimination circuit 45. When the disc 31 is the first type disc, the light emitted from the light source 47 is reflected by the label 71 as shown in FIG.
8 is not reached. When the disc 31 is the second type disc, the light emitted from the light source 47 passes through the second surface protection layer 74 as shown in FIG.
After being reflected at 5, the light passes through the second surface protective layer 74 again and reaches the photodetector 48. Therefore, in the state of being mounted on the turntable 43 in FIG. 1, the photodetector 48 can determine the presence or absence of the information surface and the protective layer on the surface of the mounted disk 31 opposite to the reproducing surface of the pickup 32. Therefore,
When the photodetector 48 does not detect the reflected light while the focus determination circuit 46 detects the focus, the disc determination circuit 45 determines that the first type disc, the focus determination circuit 46 is in focus. When the photodetector 48 detects the reflected light while detecting the disc, it can be determined that the disc is the second type disc. The disk discriminating circuit 45 sends the discrimination result to the switch selecting circuit 44, and the switch selecting circuit 44 follows the inputs to the first switch 34, the second switch 37, and the third switch.
The switch 39 is switched. That is, the switch selection circuit 4
If the discriminating result is the disc of the first type, the first switch 34, the second switch 37, and the third switch 39 are respectively switched to the side a, and the discriminating result is the disc of the second type. In this case, the first switch 34, the second switch 37, and the third switch 39 are each switched to the b side.

The information of the disk 31 converted into an electric signal by the pickup 32 is input to the first switch 34. As described above, the first switch 34 is set to the a side in the case of the first type disk by the switch selection circuit 44 and to the b side in the case of the second type disk. Therefore, the disk 3 converted into an electric signal
The information No. 1 is input to the first demodulation circuit 35 when it is determined that the disc is the first type, and is input to the second demodulation circuit 36 when it is determined that the disc is the second type.
The first demodulation circuit 35 is a circuit for demodulating the first type of disc, and demodulates the input signal and outputs a video / audio signal. The second demodulation circuit 36 is a circuit for demodulating the second type of disc, and demodulates the input signal and outputs a video / audio signal. The first type disc can be demodulated only by the first demodulation circuit 35, and the second type disc can be demodulated only by the second demodulation circuit 36. The second type disk cannot be demodulated by the first demodulation circuit 35, or the first type disk cannot be demodulated by the second demodulation circuit 36. As described above, the second switch 37 is set to the a side in the case of the first type disk by the switch selection circuit 44 and the second switch 37.
In the case of the disc of the above type, it is set to the b side. Accordingly, the output of the first demodulation circuit 35 is determined when the disc is the first type disc, and the output of the second demodulation circuit 36 is determined when the disc is the second type disc.
The signal is output from the output terminal 38 through the switch 37.
As described above, the third switch 39 is set to the a side by the switch selection circuit 44 in the case of the first type disk and the b side in the case of the second type disk. Therefore, when it is determined that the disc is the first type, the output of the first spindle drive circuit 40 is the output of the second spindle drive circuit 41 when it is determined that the disc is the second type. It is input to the spindle motor 42 through the switch 39 of No. 3. The first spindle drive circuit 40 is a circuit for driving the spindle motor 42 at a rotation speed suitable for demodulating the first type disk,
The second spindle drive circuit 41 is a spindle motor 42.
Is a circuit for driving the disk at a rotation speed suitable for demodulation of the second type disk. The optimum rotation speed is different between the first type disc and the second type disc. The first type disc can be demodulated by the first demodulation circuit 35 only when rotated by the first spindle drive circuit 40, and the second type disc can be demodulated by the second spindle drive circuit 41 only. It can be demodulated by the second demodulation circuit 36. Even if the second type disk is rotated by the first spindle drive circuit 40 or the first type disk is rotated by the second spindle drive circuit 41, demodulation cannot be performed. Therefore, according to the input, the spindle motor 42 rotates the turntable 43 at a rotation speed suitable for information reproduction in the case of each of the first type disc and the second type disc. The disk 31 is mounted on the turntable 43, and the rotation of the turntable 43 also rotates the disk 31.

As described above, according to the first embodiment of the present invention, the disc, the pickup, the pickup control circuit, the first switch, the first demodulation circuit, the second demodulation circuit, A second switch, an output terminal, a third switch, a first spindle drive circuit, a second spindle drive circuit, a spindle motor, a turntable, a switch selection circuit, a disc discrimination circuit, Equipped with a focus discriminating circuit, a light source, and a photodetector, with the disc mounted on the turntable, the optical detection of the presence or absence of an information surface and a protective layer on the surface of the mounted disc opposite to the playback surface of the pickup It is possible to discriminate whether the disc has an information surface on only one side or a disc having information sides on both sides by detecting with a device.By automating the disc type discrimination, the user can It is possible to provide an optical disk device without the need to instruct a type of click operation switches.

Next, an optical disc device according to a second embodiment of the present invention will be described with reference to the drawings.

FIG. 6 is a block diagram of an optical disc device according to a second embodiment of the present invention. In FIG. 6, reference numerals 31 to 44 and reference numeral 46 are the same as those shown in the first embodiment of the present invention. Reference numeral 49 is an auxiliary pickup, which converts information on the disk 31 on the opposite side of the pickup 32 to an electric signal. Reference numeral 50 denotes an auxiliary pickup focus determination circuit, which detects whether or not the optical beam focus of the auxiliary pickup 49 is correctly focused on the information surface of the disc 31,
The result is output to the disc discrimination circuit 52. An auxiliary pickup control circuit 51 controls the auxiliary pickup 49 so that the focus of the auxiliary pickup 49 follows the information track of the disc 31. A disc discriminating circuit 52 discriminates the disc type from the outputs of the focusing discriminating circuit 46 and the auxiliary pickup focusing discriminating circuit 50 and outputs it to the switch selecting circuit 44.

The operation of the optical disc apparatus of the second embodiment of the present invention constructed as above will be described below.

As described in the first embodiment of the present invention, the first type of disc has information recorded on one side, and the second type of disc has both sides recorded. , Their cross-sectional structures are shown in FIGS. 2 and 3.

In FIG. 6, the pickup 32 converts the information recorded on the disc 31 into an electrical signal and outputs it. The pickup control circuit 33 controls the pickup 32 so that the optical beam focus of the pickup 32 correctly follows the information track recorded on the disc 31. The focus determination circuit 46 sends a detection signal to the disc determination circuit 52 when it detects that the optical beam focus of the pickup 32 is correctly focused on the information surface of the disc 31. That is, the output of the focus determination circuit 46 indicates the presence or absence of the information surface of the reproduction surface of the pickup 32 of the disc 31. The auxiliary pickup control circuit 51 controls the auxiliary pickup 49 so that the optical beam focus of the auxiliary pickup 49 correctly follows the information track recorded on the disc 31. When the auxiliary pickup focus determination circuit 50 detects that the optical beam focus of the auxiliary pickup 49 is properly focused on the information surface of the disc 31, it sends a detection signal to the disc determination circuit 52. That is, the output of the auxiliary pickup focus determination circuit 50 indicates the presence or absence of the information surface of the reproduction surface of the auxiliary pickup 49 of the disc 31. Therefore, if the auxiliary pickup focus determination circuit 50 does not detect the focus while the focus determination circuit 46 detects the focus, the disc determination circuit 52 determines the first type of disc, the focus determination. When the auxiliary pickup focus determination circuit 50 detects the focus while the circuit 46 detects the focus, it can be determined that the disc is the second type. The disc discrimination circuit 52 sends the discrimination result to the switch selection circuit 44, and the switch selection circuit 44 switches the first switch 34, the second switch 37, and the third switch 39 according to the input. That is, the switch selection circuit 44 determines that the determination result is the first
In the case of the disk of the above type, the first switch 34, the second switch 37, and the third switch 39 are respectively switched to the a side, and when the determination result is the disk of the second type, the first switch The switch 34, the second switch 37, and the third switch 39 are switched to the b side.

The reproducing operation of each of the following types of discs is the same as that described in the first embodiment of the present invention.

As described above, according to the second embodiment of the present invention, the disc, the pickup, the pickup control circuit, the first switch, the first demodulation circuit, the second demodulation circuit, A second switch, an output terminal, a third switch, a first spindle drive circuit, a second spindle drive circuit, a spindle motor, a turntable, a switch selection circuit, and a focus determination circuit. , An auxiliary pickup, an auxiliary pickup focus discriminating circuit, an auxiliary pickup control circuit, and a disc discriminating circuit are provided, and when the disc is mounted on the turntable, the disc is mounted on a surface opposite to the pickup reproducing surface. Whether the disc has an information surface on only one side or a disc having information surfaces on both sides is detected by detecting the focus of the auxiliary pickup depending on the presence or absence of the information surface and the protective layer. That it can, by automating the determination of the kind of the disk, the user can provide an optical disk apparatus is not necessary to indicate the type of disk operation switch.

In the second embodiment of the present invention, the auxiliary pickup is used only for determining the presence / absence of the information surface opposite to the reproducing surface of the pickup. However, the auxiliary pickup is different from the reproducing surface of the pickup. It is also possible to adopt a configuration used for reproducing information on the information side.

Next, referring to the drawings, the third embodiment of the present invention will be described.
The optical disk device of the embodiment will be described.

FIG. 7 is a block diagram of an optical disc device according to a third embodiment of the present invention. In FIG. 7, reference numerals 31 and 33 to 46 are the same as those in the first embodiment of the present invention. Reference numeral 53 is a pickup, which converts information on the disk 31 into an electric signal. 54
Is a moving base for moving the pickup 53 along the rail 55. Reference numeral 55 denotes a rail, which serves as a movement guide for the movable base 54, and the pickup 53 is arranged so that information on both sides of the disk 31 can be recorded and reproduced by moving the movable base 54 along the rail. Reference numeral 56 denotes a light source, which is arranged on the upper surface of the disk 31 and at a position where the pickup 53 does not hit even if the pickup 53 is moved to the upper surface side, and irradiates the upper surface of the disk 31 with light obliquely. Reference numeral 57 denotes a photodetector, which is arranged on the upper surface of the disk 31 and at a position where it does not hit even if the pickup 53 is moved to the upper surface side, detects the presence or absence of the light emitted from the light source 56 reflected by the disk 31, and The result is output to the disc discrimination circuit 45.

FIG. 8 is a diagram showing the positions of the pickup, the light source, and the photodetector when the movable base is located on the upper surface of the disk in the optical disk device according to the third embodiment of the present invention.

The operation of the optical disc device of the third embodiment of the present invention constructed as above will be described below.

As described in the first embodiment of the present invention, the first type disc has information recorded on one side, and the second type disc has information recorded on both sides. , Their cross-sectional structures are shown in FIGS. 2 and 3.

When disc type is determined in FIG. 7, the movable base 54 is placed on the lower face of the disc.
The pickup 53 converts the information recorded on the disc 31 into an electric signal and outputs it. The pickup control circuit 33 causes the optical beam focus of the pickup 32 to correctly follow the information track recorded on the disc 31.
The pickup 53 is controlled. The focus determination circuit 46 sends a detection signal to the disc determination circuit 45 when it detects that the optical beam focus of the pickup 53 is correctly focused on the information surface of the disc 31. That is, the output of the focus determination circuit 46 is
The presence or absence of the information surface of the reproduction surface of the pickup 53 of the disc 31 is indicated. The light source 56 obliquely emits light to the surface of the disc 31 opposite to the reproduction surface of the pickup 32.
The photodetector 57 detects the presence or absence of light emitted from the light source 56 reflected by the disc 31, and outputs it to the disc discrimination circuit 45. As described in the first embodiment of the present invention,
If the disc 31 is the first type disc,
The light emitted from the light source 56 does not reach the photodetector 57. When the disc 31 is the second type disc, the light emitted from the light source 56 reaches the photodetector 57. Therefore, the photodetector 57 can determine the presence or absence of the information surface and the protective layer on the surface opposite to the reproduction surface of the pickup 53 of the mounted disk 31 when mounted on the turntable 43. Therefore, the disc discrimination circuit 45
Is a disc of the first type when the photodetector 57 does not detect reflected light while the focus determination circuit 46 is detecting focus, and the focus determination circuit 46 detects focus. When the photodetector 57 detects the reflected light in the state where the disk is present, it can be determined that the disc is the second type disc. Disc discrimination circuit 4
5 sends this determination result to the switch selection circuit 44, and the switch selection circuit 44 follows the input to the first switch 3
4, the second switch 37, the third switch 39 is switched. That is, the switch selection circuit 44 determines whether the first switch 34, the second switch 34, or the like when the determination result is the first type disk.
Switch 37 and the third switch 39 to the side a, and when the determination result is the second type disk, the first switch 34, the second switch 37, and the third switch 39 are respectively set to b. Switch to the side.

The reproducing operation of each of the following types of discs is the same as that described in the first embodiment of the present invention.
When the disc type determination result is the second type disc, the pickup 53 is placed on the moving base 54 and the rail 55 is placed in order to read the information on the upper surface.
Can move to the upper surface side. As shown in FIG. 8, at this time, the light source 56 and the photodetector 57 are arranged at positions where they do not hit the pickup, and do not hinder the reading operation to the upper surface of the pickup 53.

As described above, according to the third embodiment of the present invention, the disc, the pickup control circuit, the first switch, the first demodulation circuit, the second demodulation circuit, and the second demodulation circuit. A switch, an output terminal, a third switch, a first spindle drive circuit, a second spindle drive circuit, a spindle motor, a turntable, a switch selection circuit, a disc determination circuit, and a focus determination. A circuit, a pickup, a moving base, a rail, a light source, and a photodetector are provided, and the light source and the photodetector are arranged at positions where the pickup does not hit even if the pickup is transferred to the upper surface side of the disc. With the disc mounted on the turntable,
By detecting the presence or absence of the information surface and the protective layer on the surface opposite to the playback surface of the mounted disc pickup, it is possible to determine whether the disc has the information surface on only one side or the information surface on both sides. By automatically discriminating the disc type, the user does not need to specify the disc type with the operation switch, and in the case of a disc that has information on both sides, it does not need to be flipped over by the user. It is possible to provide an optical disc device capable of reproducing the information described above.

Next, an optical disc device according to a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 9 is a block diagram of an optical disc device according to a fourth embodiment of the present invention. In FIG. 9, reference numerals 31 to 55 are the same as those shown in the third embodiment of the present invention. Reference numeral 58 denotes a light source, which obliquely irradiates the upper surface of the disk 31 with light. A photodetector 59 detects the presence or absence of light emitted from the light source 56 reflected on the upper surface of the disc 31, and outputs the result to the disc discrimination circuit 45. Reference numeral 60 denotes a detecting means transfer base, to which the light source 58 and the photodetector 59 are fixed. Reference numeral 61 denotes an up-and-down mechanism that changes the distance between the detection means transfer table 60 and the disk 31.

FIG. 10 is a diagram showing the positions of the pickup, the light source, and the photodetector when the movable base is located on the upper surface of the disk in the optical disk device of the fourth embodiment of the present invention.

The operation of the optical disc apparatus of the fourth embodiment of the present invention constructed as above will be described below.

As described in the first embodiment of the present invention, the first type disc has information recorded on one side, and the second type disc has information recorded on both sides. , Their cross-sectional structures are shown in FIGS. 2 and 3.

In FIG. 9, when the disc type is discriminated, the movable base 54 is placed on the lower face of the disc.
The pickup 53 converts the information recorded on the disc 31 into an electric signal and outputs it. The pickup control circuit 33 causes the optical beam focus of the pickup 32 to correctly follow the information track recorded on the disc 31.
The pickup 53 is controlled. The focus determination circuit 46 sends a detection signal to the disc determination circuit 45 when it detects that the optical beam focus of the pickup 53 is correctly focused on the information surface of the disc 31. That is, the output of the focus determination circuit 46 is
The presence or absence of the information surface of the reproduction surface of the pickup 53 of the disc 31 is indicated. At this time, the up-and-down mechanism 59 positions the detection means transfer table 60 at the lowermost position, and the light source 58 is the disk 3
The surface opposite to the reproducing surface of the first pickup 32 is obliquely irradiated with light. The photodetector 59 detects the presence or absence of light emitted from the light source 58 reflected by the disc 31 and outputs it to the disc discrimination circuit 45. As described in the first embodiment of the present invention, when the disc 31 is the first type disc, the light emitted from the light source 58 does not reach the photodetector 59. When the disc 31 is the second type disc, the light emitted from the light source 58 reaches the photodetector 59. Therefore, the pickup 5 of the mounted disc 31 is mounted on the turntable 43.
The photodetector 59 can determine the presence or absence of the information surface and the protective layer on the surface opposite to the reproducing surface of No. 3. Therefore, when the photodetector 57 does not detect the reflected light while the focus determination circuit 46 detects the focus, the disc determination circuit 45 determines that the first type disc, the focus determination circuit 46 When the photodetector 59 detects the reflected light while the focus is detected, it can be determined that the disc is the second type. The disc discrimination circuit 45 sends the discrimination result to the switch selection circuit 44, and the switch selection circuit 44 follows the inputs to the first switch 34, the second switch 37, and the third switch 39.
Switch. That is, when the determination result is the first type disk, the switch selection circuit 44 determines that the first switch 3
4, the second switch 37 and the third switch 39 are respectively switched to the side a, and when the determination result is the second type disk, the first switch 34, the second switch 37,
The third switches 39 are respectively switched to the b side.

The reproducing operation of the following types of discs is the same as that described in the first embodiment of the present invention.
When the disc type determination result is the second type disc, the pickup 53 is placed on the moving base 54 and the rail 55 is placed in order to read the information on the upper surface.
Can move to the upper surface side. As shown in FIG. 10, at this time, the up-and-down mechanism 59 moves the detecting means transfer base 60 upward and transfers it to a position where it does not hit the pickup 53 and the moving base 54, which hinders the reading operation on the upper surface of the pickup 53. Don't give.

As described above, according to the fourth embodiment of the present invention, the disc, the pickup control circuit, the first switch, the first demodulation circuit, the second demodulation circuit, and the second A switch, an output terminal, a third switch, a first spindle drive circuit, a second spindle drive circuit, a spindle motor, a turntable, a switch selection circuit, a disc determination circuit, and a focus determination. A circuit, a pickup, a moving base, a rail, a light source, a photodetector,
Detecting means A transfer table and an up-and-down mechanism are provided to detect the presence or absence of the information surface and the protective layer on the surface opposite to the reproducing surface of the pickup of the mounted disk while the disk is mounted on the turntable. Discriminates whether the disc has an information side on only one side or a disc with both sides having information side.By automating the disc type discrimination, the user needs to indicate the disc type with the operation switch. In the case of a disc having no information and having information on both sides, it is possible to provide an optical disc device capable of reproducing information on both sides without the user having to turn the disc over.

Next, an optical disc device according to a fifth embodiment of the present invention will be described with reference to the drawings.

FIG. 11 is a block diagram of the optical disk device of the fifth embodiment of the present invention. In FIG. 11, reference numerals 31 to 39, 42 to 44 and 4
6 is the same as that shown in the first embodiment of the present invention. Reference numeral 58 denotes a light source, which obliquely irradiates the upper surface of the disk 31 with light. A photodetector 59 detects the presence or absence of light emitted from the light source 56 reflected on the upper surface of the disc 31, and outputs the result to the disc discrimination circuit 62. 60
Is a detection means transfer table, to which a light source 58 and a photodetector 59 are fixed. Reference numeral 61 denotes an up-and-down mechanism that changes the distance between the detection means transfer table 60 and the disk 31. A disc discriminating circuit 62 discriminates the disc from the outputs of the focus discriminating circuit 46 and the photodetector 59, and outputs the disc to the switch selecting circuit 44. 63
Is a disc discrimination control circuit, which controls the disc discrimination circuit 62, the vertical movement mechanism 61, the first spindle drive circuit 64, and the second spindle drive circuit 65. Reference numeral 64 denotes a first spindle drive circuit, which generates a spindle motor drive signal when reproducing the first type disc. Reference numeral 65 denotes a second spindle drive circuit, which generates a spindle motor drive signal when reproducing a second type disc.

FIG. 12 is a diagram showing the positions of the disc and the detecting means transfer base during disc type discrimination in the optical disc device of the fifth embodiment of the present invention.

FIG. 13 is a diagram showing the positions of the disk for reproducing a disk and the detecting means transfer table in the optical disk device of the fifth embodiment of the present invention.

The operation of the optical disc apparatus of the fifth embodiment of the present invention constructed as above will be described below.

As described in the first embodiment of the present invention, the first type of disc has information recorded on one side, and the second type of disc has both sides recorded. , Their cross-sectional structures are shown in FIGS. 2 and 3.

In FIG. 11, when disc type is discriminated, the disc discrimination control circuit 63 instructs the first spindle drive circuit 64 and the second spindle drive circuit 65 to stop. As a result, the spindle motor 42 stops and the disk 31 also stops. In this state, the disc discriminating control circuit 63 controls the up-down mechanism 53 to control the detecting means transporting base 54 and move the detecting means transporting base 54 to the disc type discriminating position. The position of the detection means transfer table 54 shown in FIG. 12 is the disc type determination position.

In FIG. 11, the pickup control circuit 3
Reference numeral 3 controls the pickup 32 so that the optical beam focus of the pickup 32 correctly follows the information track recorded on the disc 31. The focus determination circuit 46 sends a detection signal to the disc determination circuit 45 when it detects that the optical beam focus of the pickup 32 is correctly focused on the information surface of the disc 31. That is, the output of the focus determination circuit 46 indicates the presence or absence of the information surface of the reproduction surface of the pickup 32 of the disc 31. The light source 58 obliquely irradiates the surface of the disc 31 opposite to the reproduction surface of the pickup 32 with light. The photodetector 59 detects the presence or absence of the light emitted from the light source 58 reflected by the disc 31, and outputs it to the disc discriminating circuit 62. As described in the first embodiment of the present invention, when the disc 31 is the first type disc, the light source 58
The light emitted from does not reach the photodetector 59. When the disc 31 is the second type disc, the light emitted from the light source 58 passes through the second surface protection layer 74 and is reflected by the second information surface 75, as shown in FIG. After that, the light passes through the second surface protection layer 74 again and reaches the photodetector 59.
Therefore, when the photodetector 59 does not detect the reflected light while the focus determination circuit 46 detects the focus, the disc determination circuit 62 determines that the first type disc, the focus determination circuit 46 When the photodetector 59 detects the reflected light while the focus is detected, it can be determined that the disc is the second type. At this time, the light source 58 and the photodetector 59 are the second
Since the disk 31 does not rotate even if it approaches the surface protection layer, the surface of the second surface protection layer 74 does not shake up and down due to surface wobbling or the like, and the light source 58, the photodetector 59, and the second surface protection layer. 74 will not be hit. The disc discriminating circuit 62 sends the discrimination result to the switch selecting circuit 44, and the switch selecting circuit 44 receives the first switch 34 and the second switch 34 in accordance with the input.
The switch 37 and the third switch 39 are switched. That is, the switch selection circuit 44 switches the first switch 34, the second switch 37, and the third switch 39 to the side a when the discriminating result is the disc of the first type, and the discriminating result is the second. In the case of discs of
The switch 34, the second switch 37, and the third switch 39 are switched to the b side. Upon completion of disc discrimination, the disc discrimination control circuit 63 stores the disc discrimination result in the disc discrimination circuit 62, controls the detecting means transfer base 60 by the up-down mechanism 61, and moves it to the reproduction position.
The position of the detection means transfer table 60 shown in FIG. 13 is the reproduction position.

This is because when the position of the detecting means transfer table 54 is the disc type discriminating position, the light source 58 and the photodetector 5 are arranged.
When the disk 31 is rotated when the disk 9 is approaching the second surface protection layer, the surface of the second surface protection layer 74 shakes up and down due to surface wobbling, etc., and the light source 58, the photodetector 59, and the second surface protection layer 74 hit each other. Because there is a possibility. Up and down mechanism 61 up to this state
After moving the, the disc discrimination control circuit 62 instructs the first spindle drive circuit 64 and the second spindle drive circuit 65 to start rotation. The information of the disc 31 converted into an electric signal by the pickup 32 is input to the first switch 34. As described above, the first switch 34 is set to the a side in the case of the first type disk by the switch selection circuit 44 and to the b side in the case of the second type disk. Therefore, the information of the disc 31 converted into an electric signal is sent to the first demodulation circuit 35 when the disc is discriminated as the first type disc, and the second information when discriminated as the second type disc. Demodulation circuit 36
Is input to The first demodulation circuit 35 is a circuit for demodulating the first type of disc, and demodulates the input signal and outputs a video / audio signal. The second demodulation circuit 36 is a circuit for demodulating the second type of disc, and demodulates the input signal and outputs a video / audio signal. The first type disc can be demodulated only by the first demodulation circuit 35, and the second type disc can be demodulated only by the second demodulation circuit 36. The second type disk cannot be demodulated by the first demodulation circuit 35, or the first type disk cannot be demodulated by the second demodulation circuit 36. As described above, the second switch 37 is set to the a side in the case of the first type disk and to the b side in the case of the second type disk by the switch selection circuit 44. Therefore, the output of the first demodulation circuit 35 is determined when the disc is the first type disc, and the output of the first demodulation circuit 35 is determined when the disc is the second type disc.
Is output from the output terminal 38 through the second switch 37. As described above, the third switch 39 is set to the a side by the switch selection circuit 44 in the case of the first type disk and the b side in the case of the second type disk. Therefore, when it is determined that the disc is of the first type, the output of the first spindle drive circuit 64 is determined when it is disc of the second type,
The output of the second spindle drive circuit 65 is input to the spindle motor 42 through the third switch 39. First
Is a circuit for driving the spindle motor 42 to a rotation speed suitable for demodulating the first type disk, and a second spindle drive circuit 65 is for driving the spindle motor 42 for the second type disk. This is a circuit that drives at a rotation speed suitable for demodulation. The optimum rotation speed is different between the first type disc and the second type disc. The first type disc can be demodulated by the first demodulation circuit 35 only when rotated by the first spindle drive circuit 64, and the second type disc can be demodulated by the second spindle drive circuit 65 only when rotated. It can be demodulated by the second demodulation circuit 36. The second type of disk is the first spindle drive circuit 64, or the first type of disk is the second spindle drive circuit 6.
It cannot be demodulated even if rotated at 5. Therefore, according to the input, the spindle motor 42 rotates the turntable 43 at a rotation speed suitable for information reproduction in the case of each of the first type disc and the second type disc. The disk 31 is mounted on the turntable 43, and the rotation of the turntable 43 also rotates the disk 31. At this time, as shown in FIG. 13, the light source 5
8 and the photodetector 59 are distant from the second surface protection layer, the disk 31 rotates, and even if the surface of the second surface protection layer 74 shakes up and down due to surface wobbling etc., the light source 58 and the photodetector 5
9 does not hit the second surface protection layer 74. Therefore,
In FIG. 11, the light source 58 and the photodetector 59 do not damage the disc 31 in any case.

As described above, according to the fifth embodiment of the present invention, the disc, the pickup, the pickup control circuit, the first switch, the first demodulation circuit, the second demodulation circuit, The second switch, the output terminal, the third switch, the spindle motor, the turntable, the switch selection circuit, the focus determination circuit, the light source, the photodetector, the detection means transfer base, and the upper and lower. By including the mechanism, the disc discriminating circuit, the disc discriminating control circuit, the first spindle drive circuit, and the second spindle drive circuit,
With the disc mounted on the turntable, by detecting the presence or absence of the information layer and the protective layer on the side opposite to the playback surface of the mounted disc pickup, the disc having only one side or the information side on both sides. It is possible to discriminate whether the disc has a disc, and by automating the discrimination of the disc type, the user does not need to indicate the disc type with the operation switch, and the disc is scratched by the light source and photodetector. It is possible to provide a non-optical disc device.

In the embodiment of the present invention, the optical disc device dedicated to reproduction has been described, but the same effect can be exhibited in the optical disc device capable of recording and reproducing. Further, in the embodiment of the present invention, the detection means is described as an optical one, but other means, for example, one that measures capacitance or one that detects a metal on the information surface can obtain the same effect. It is what is done.

[0065]

As described above, according to the present invention, the pickup for reading or writing the information recorded on the optical disc and the surface for reading or writing the information by the pickup of the optical disc. By providing a detection unit that detects the presence or absence of the information recording surface on the opposite side, it is possible to determine whether the disc has the information surface on only one side or the information surface on both sides. By automating, it is possible to provide an excellent optical disc device in which the user does not need to indicate the disc type by the operation switch.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a cross section of a first type disc reproduced by the optical disc device of the embodiment.

FIG. 3 is a diagram showing a cross section of a second type of disc reproduced by the optical disc device of the embodiment.

FIG. 4 is a view showing the operation of the photodetector when the first type disk is mounted on the optical disc device of the embodiment.

FIG. 5 is a view showing the operation of the photodetector when the second type disk is mounted on the optical disc device of the embodiment.

FIG. 6 is a configuration diagram of an optical disc device according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 8 is a diagram showing the positions of a pickup, a light source, and a photodetector when the movable base is located on the upper surface of the disk in the optical disc device of the embodiment.

FIG. 9 is a configuration diagram of an optical disc device according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing the positions of a pickup, a light source, and a photodetector when the movable base is located on the upper surface of the disk in the optical disc device of the embodiment.

FIG. 11 is a configuration diagram of an optical disc device according to a fifth embodiment of the present invention.

FIG. 12 is a diagram showing the positions of the disc and the detection means transfer base during disc type discrimination in the optical disc device of the embodiment.

FIG. 13 is a diagram showing the positions of the disc and the detection means transfer base during disc reproduction in the optical disc device of the embodiment.

FIG. 14 is a configuration diagram of a conventional optical disc device.

FIG. 15 is a diagram showing a cross section of a first type disk reproduced by an optical disk device of a conventional example.

FIG. 16 is a diagram showing a cross section of a second type of disc reproduced by an optical disc device of a conventional example.

[Explanation of symbols]

 31 disc 32 pickup 33 pickup control circuit 34 first switch 35 first demodulation circuit 36 second demodulation circuit 37 second switch 38 output terminal 39 third switch 40 first spindle drive circuit 41 second spindle Drive circuit 42 Spindle motor 43 Turntable 44 Switch selection circuit 45 Disc discrimination circuit 46 Focus discrimination circuit 47 Light source 48 Photodetector 49 Auxiliary pickup 50 Auxiliary pickup focus discrimination circuit 51 Auxiliary pickup control circuit 52 Disc discrimination circuit 53 Pickup 54 Move Base 55 Rail 56 Light source 57 Photodetector 58 Light source 59 Photodetector 60 Detection means transfer base 61 Up / down mechanism 62 Disc discriminating circuit 63 Disc discriminating control circuit 64 First spindle control circuit 65 Second spindle Dollar control circuit

Claims (8)

[Claims] 1. An optical disc device capable of reproducing or recording information on an optical disc having an information recording surface on one side or an optical disc having an information recording surface on both sides, wherein the optical disc device is recorded on the optical disc. A pickup is provided for reading information or writing information, and a detecting means for detecting the presence or absence of an information recording surface opposite to the surface from which the pickup of the optical disc reads or writes information. Optical disc device. 2. The optical disc device according to claim 1, wherein the detection means optically detects reflection on the information recording surface. 3. A light source for irradiating light on a surface opposite to a surface on which an optical disk pickup is reading or writing information, and a light from the light source is the optical disk pickup. 3. The optical disc device according to claim 2, further comprising a detector for detecting reflected light on the side opposite to the side from which information is read or written. 4. The light source irradiates light to a surface opposite to a surface on which an optical disc pickup is reading or writing information at a certain incident angle. Optical disc device. 5. The detection means includes an auxiliary pickup for reading or writing information on the side opposite to the side on which the pickup of the optical disk reads or writes information, and the focus of the auxiliary pickup is the optical disk. 3. The optical disc device according to claim 2, further comprising: focus detection means for detecting whether or not the information recording surface is in focus. 6. A transport means for transporting the pickup so that information on both sides of the optical disk can be read or written, and when the pickup is transported to the same surface as the detection means, it does not hit the pickup. The optical disc device according to claim 1, wherein the detecting means is disposed at a position. 7. A pickup transfer means for transferring the pickup so that information on both sides of the optical disk can be read or written, and a position which does not hit the pickup when the pickup is transferred to the same surface as the detection means. An optical disk device according to claim 1, further comprising a detector transfer means for transferring the detection means. 8. The optical disk device according to claim 1, further comprising detector position changing means for changing the distance between the detecting means and the information surface of the optical disk.