JPH10302382A - Optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable starting and carriage return with a correct convergent lens without being disturbed by the transfer or the like of the convergent lens due to an external force by executing the operation of the starting of a device, the carriage return from an abnormal state, the re-operation of focusing and the carriage return from sleep or the like after executing the switching operation into the desired convergent lens of plural convergent lenses. SOLUTION: When a disk 7 is installed, first, the convergent lens 5 for the base material thickness 1.2 mm is transferred to the using position with a micro- computer 48. Next, a disk motor 6 is driven to rotate the disk 7, and the semiconductor laser 1 of wavelength 780 nm is emitted. A focus actuator 13 is operated, when the address is outputted, the disk 7 is judged to be CD-R and the operation is continued. When the address is not outputted in spite of the scheduled time elapsing, the disk 7 is judged to be DVD, the focusing lens 42 for the base material thickness 0.6 mm is transferred to the using position and the semiconductor laser 43 of wavelength 650 nm is emitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing method for reproducing information recorded in advance by irradiating a plurality of types of information carriers having different substrate thicknesses with a light beam and / or recording arbitrary information. It concerns the device.

[0002]

2. Description of the Related Art The prior art is used in a CD (compact disk) player, which is a representative example of an optical reproducing apparatus.
There are CD media and astigmatic focus control devices. As shown in the cross section of FIG. 3, the CD media (hereinafter simply referred to as CD) is provided with pits with a concave and convex structure according to information on a single-plate base material with a thickness of about 1.2 mm, and then deposits an aluminum reflective film on top of it. It is formed by the method described above. As shown in FIG. 3, the information is read from the reflected light by converging and irradiating a light beam onto a pit through a base material by a converging lens. Therefore, the converging lens is optimally designed in consideration of the thickness of the base material so that the light beam is appropriately converged after passing through the base material having a thickness of 1.2 mm. Generally, in a CD, a semiconductor laser having a wavelength of 780 nm is used as a light source.

In a CD player, focus control is performed so that a light beam always has a predetermined convergence state on an information surface having pits. Focus control uses a detection method such as the astigmatism method to detect the convergence state of the light beam on the information surface, and sets the focusing lens to CD according to the detection signal
This is performed by driving in a direction perpendicular to the information surface.

In the astigmatism method, reflected light from a disk converged by a pair of converging lenses and a cylindrical lens is detected using a four-divided detector. FIG.
From the state where the convergence point of the light beam is separated from the disk,
FIG. 6 illustrates the state of the light beam on the four-segment detector when approaching the disk sequentially. 2A shows the state most distant from the disk, FIG. 2C shows the just focus state, and FIG. 2E shows the state closest to the disk. (b) and (d) are intermediate states between (a) and (c) and (c) and (e), respectively. In the figure, the track longitudinal direction is the vertical direction, and the track transverse direction is the horizontal direction. The two division lines of the four-divided detector are provided in the track longitudinal direction and the horizontal direction, and the difference between the sums of the light amounts of the diagonal detectors becomes a focus error signal. The principle and configuration of the astigmatism method are known to those skilled in the art. Also, "Optical Disc Technology", supervised by Morio Onoue Radio Engineering Co., Ltd. Chapter 1.2.5 Focusing, Detection of Tracking Error Page 83 Since it is described in detail in prior art documents such as pp. 85, it will not be described in detail.

[0005]

On the other hand, recently, for the purpose of increasing the capacity of an optical disk, a thin medium having a substrate thickness of 0.6 mm using a light source of a 650 nm short wavelength laser represented by a DVD or the like has been proposed. As shown in FIG. 4, the thin medium has a structure in which, for example, two single plates having the same structure as the CD but only the thickness of the base material being 0.6 mm are laminated with the information surface inside. The light beam is converged and irradiated on the information surface by the converging lens through the disk base material surface of the thin medium to read or write information. As described above, the converging lens is optimally designed so that a predetermined converging state can be obtained by passing through a substrate having a thickness of 0.6 mm.

Therefore, the light source wavelength 780n represented by a CD
m, media with a base material thickness of 1.2 mm and thin media with a light source wavelength of 650 nm, typically DVD, and a base material thickness of 0.6 mm In addition, a configuration has been proposed in which two semiconductor lasers are mounted as light sources and are configured to be operable by switching between them.

FIG. 5 is a structural view of an optical head used in such an apparatus. This optical head is 650nm as light source
And two semiconductor lasers 43 and 1 of 780 nm, and converging lenses 42 and 5 for a base material thickness of 0.6 mm and 1.2 mm. The converging lenses 42 and 5 are mounted on a disk-shaped movable body 56. The movable body 56 is movable along an axis 54 in a focus direction perpendicular to the disk, and is rotated about the axis
The two converging lenses 42 and 5 can be switched. In an apparatus equipped with a plurality of converging lenses and a plurality of light sources, it is of course necessary to select and use a converging lens and a light source that match the medium to be mounted. However, in the optical head having this structure, the movable body 5
6 is configured to be freely rotatable about the shaft 54,
It is easily deviated from its normal operating position due to external vibration or impact. If the shift amount is large, the light beam is blocked by the structure for holding the two converging lenses 42 and 5 and a focus control jump occurs when the apparatus is operating. In addition, if the movable body stops between the two regular positions because the shaft friction cannot be reduced to zero, the apparatus may fall into an inoperable state. This is even more important when activating the device or when returning from a sleep state to reduce power consumption. During device stop or sleep,
Since the operation of the apparatus is not continuous, it is not possible to determine the displacement of the movable body 56 only from the state of the apparatus before and after.

There is another problem in an apparatus for reproducing or recording both a medium represented by a CD and a thin medium represented by a DVD. FIG. 8 shows the light wavelength dependence of the reflectance of a recording film used in a write-once CD medium commonly called CD-R (CD write once). CD-R media has a high reflectance for light with a wavelength of 780 nm, but a wavelength of 650 nm
In this case, the reflectance is extremely reduced, and most of the irradiated light energy is absorbed. This means that when irradiating a CD-R media with a light beam of 650 nm wavelength, not only the light does not return, but also the absorbed light energy changes to heat, causing thermal damage to the CD-R recording film. In the worst case, it may be possible to destroy already recorded information.

[0009]

In order to solve the above-mentioned problems, in the optical recording / reproducing apparatus of the present invention, a switching operation for switching from a plurality of converging lenses to a specific converging lens is performed, and then the starting operation of the apparatus is performed. , Return operation from abnormal state,
It is configured to perform a re-operation of the focus control, an operation of returning from the device sleep state, and an operation of returning from the focus sleep. Also, a means is provided for storing the type of media installed immediately before the sleep or abnormal state, the convergent lens or light source used, and switching to the convergent lens or light source according to the storage before returning from the abnormal state or sleep. An operation is performed. Further, at the time of starting the apparatus, a light source having a wavelength of 780 nm is first operated.

With this configuration, recording / reproducing operations are performed on a plurality of types of media. Therefore, in a device having a plurality of converging lenses, even if the position of the converging lens is moved or switched due to external force or the like. Using the correct converging lens, it is possible to perform a start-up operation of the device, a return operation from an abnormal state, a re-operation of focus control, a return operation from the device sleep state, and a return operation from the focus sleep. Further, even for a medium whose absorption rate increases at 650 nm, a safe device start-up operation can be performed without damaging recorded data.

[0011]

FIG. 1 is a block diagram of a focus control apparatus according to a first embodiment of the present invention.

A light beam generated by a semiconductor laser 1 that emits laser light having a wavelength of 780 nm is collimated by a collimator lens 2 and then reflected by a polarizing beam splitter 3 to form a polarizing beam splitter 41 and a λ / 4 plate 4 ( λ is the wavelength of the light beam), and is converged by a converging lens 5 for a substrate thickness of 1.2 mm or a converging lens 42 for a substrate thickness of 0.6 mm.
The light is converged and irradiated on the disk 7 rotated by the motor 6.

A light beam generated by a semiconductor laser 43 which emits a laser beam having a wavelength of 650 nm is converted into a parallel light by a collimator lens 44 and then reflected by a polarization beam splitter 41, and the λ / 4 plate 4 (λ is a light beam) Wavelength)
Through the converging lens 5 for a substrate thickness of 1.2 mm or the converging lens 42 for a substrate thickness of 0.6 mm, and converges and irradiates the disk 7 rotated by the motor 6. The converging lenses 5 and 42 are mounted together on the focus actuator 13, and are driven by a driving circuit 45 so that a light beam from a light source can be selectively switched and incident on one of the converging lenses.
2 are provided. Since the configuration of this actuator is known and has already been described in the page of the prior art of the present application and in FIG. 5, detailed description thereof will be omitted.

The light reflected from the disk 7 is condensed by a converging lens 5,
The light passes through the λ / 4 plate 4 and the polarization beam splitters 41 and 3, is converged by the detection lens 15 and the cylindrical lens 16, and is irradiated on the photodetector 8 having a four-part structure. The two semiconductor lasers 1 and 43 are driven by a drive circuit 4 which can be turned on / off by a control signal from a microcomputer 48.
6 and 47, so that their operation and non-operation can be switched independently. The operation and non-operation of the drive circuit 49 of the motor 6 can also be switched by the microcomputer 48 so that the rotation and stop of the motor 6 can be controlled by the microcomputer 48.

The light reflected from the disk 7 is converged by a converging lens 5,
The light passes through the λ / 4 plate 4 and the polarizing beam splitter 3, and the detection lens 15 and the cylindrical lens 16 intentionally generate astigmatism. This is to detect a signal.

The principle and configuration of the focus error signal detection using the astigmatism method are known to those skilled in the art, and are described in “Optical Disc Technology”, supervised by Morio Onoe, Radio Technology Company, Chapter 1.2.5. −Detection of tracking and tracking errors Page 83 to 85
, Etc., are described in detail in the prior art documents, and the detailed description is omitted. The output of the quadrant photodetector 8 is
The adders 17 and 18 calculate the sum of the light amounts of the respective diagonal detectors. The difference between the outputs of the adders 17 and 18 is calculated by the differential amplifier 9. It is a well-known fact that the signal detected in this way becomes a focus error signal indicating the convergence state of the light beam on the disk 7.

A focus error signal output from the differential amplifier 9 is supplied to a phase compensation circuit 10 for securing control stability of focus control, a gain compensation circuit 11 for securing loop gain required for focus control, and a microcomputer. 4
A switch 50 for switching the operation / non-operation of the focus control in response to the command signal from the controller 8 and the input to the focus actuator 13 via the drive circuit 12 constitute a focus control system. The focus actuator 13 is an element that moves the converging lens 5 substantially in a direction perpendicular to the disk 7 in accordance with a signal output from the drive circuit 12. The output of the adder 17 and the adder 18 is the adder 1
9, the total reflected light amount from the disk 7 is calculated. It is known that the information recorded on the disk 7 can be read by the signal of the total reflection light amount. Also, an address for identifying an information track arranged on the disk 7 described later can be read by the output signal of the adder 19. The output signal of the adder 19 is input to an address reading circuit 21 to read an address provided on the disk 7. Address reading circuit 21
Is sent to the microcomputer 48, and the microcomputer 48 is configured to know the address where the light beam is located. Further, a switching signal generator 51 for switching the convergent lens to be used to either the convergent lens 5 or the convergent lens 42 is provided. The switching signal generator 51 drives and operates a lens switching mechanism for switching a convergent lens via a drive circuit 45 with an appropriate drive signal, and switches the lens to be used to the convergent lens 1 or the convergent lens 42. An instruction signal for instructing a convergent lens to be used is input from the microcomputer 48 to the switching signal generator 51 so that the operation of the switching signal generator 51 can also be controlled from the microcomputer 48. Further, a memory 53 is connected to the microcomputer 48, and the microcomputer 48 can store an arbitrary numerical value or state by storing it in the memory 53.

FIG. 6 is a structural view of the disk 7 used in the above-described focus control device according to the present invention. On the disk 7, a track having a convex structure with an optical depth of approximately 8 / λ is formed for the wavelength λ of the semiconductor laser 1 or 43. In the disk 7, four address portions for track identification are provided at equal intervals in the circumferential direction from ID0 to ID3 on each track. The address portion of each track is arranged at the same position in the circumferential direction,
When the disk 7 is rotated by the motor 6 and the focus control is operating properly, the address can be read at regular intervals. FIG. 7 is an enlarged view of ID0 circled in FIG. The address portion is formed of a pit row having a convex structure, and an address reading circuit 21 is provided.
Reads the address where the light beam is located from the change in the amount of reflected light due to this pit row. The width of each pit is smaller than the track width, and the length of the pit is about the diameter from the radius of the light beam. The operation of the focus control device according to the embodiment of the present invention shown in FIG. 1 includes a series of start-up operations started after the disk 7 is mounted on the device, a sleep operation for reducing power consumption, and an occurrence of an error. Will be described in more detail step by step. As described above, there are a plurality of types of disks 7. For the sake of simplicity, it is assumed that, of these plural types of disks, only the following two types of disks A and B are mounted on the apparatus. That is, the disc A is a single-plate disc having a base material thickness of 1.2 mm, and a write-once recording film that can be recorded only once is deposited on its information surface. The reflection / absorption characteristics of this write-once recording film vary greatly depending on the light wavelength. As shown in FIG. 8, the write-once recording film has a large reflectance of about 70% at the light wavelength of 780 nm, but has a large reflectance at the light wavelength of 650 nm. The rate drops significantly and absorbs most of the emitted light energy. This disc A is generally "CD-R" or "CD WRITE-ONC"
It is similar to what is widely spread in the world as "E". If the disk A is irradiated with a light beam of 650 nm for a predetermined time or more, the already recorded data may be damaged. That is, the disk A is optimally designed for the light beam of the wavelength 780 nm emitted from the semiconductor laser 1.

On the other hand, the disc B is a disc in which two single plates having a base material thickness of 0.6 mm are laminated, and information is recorded on the information surface thereof at a higher density than the disc A, and a light beam having a wavelength of 650 nm is used. Recording operation on the disc B only,
A signal that has already been recorded can be read. A reflective film of AL is deposited on the information surface and has a reflectance of around 70% for a light beam with a wavelength of 650 nm. That is, the disc B is optimally designed for the light beam of the wavelength 650 nm emitted from the semiconductor laser 43. This disc B is similar to the disc whose standard was recently disclosed and which is generally known as "DVD".

First, a description will be given of a series of starting operations which are started after the disk 7 is mounted on the apparatus.

When the disc 7 is mounted on the motor 6 by a loading / chucking mechanism (not shown), the microcomputer 48 first unconditionally determines whether the two converging lenses 5 and 42 are currently used. A command signal for switching to the converging lens 5 for a material thickness of 1.2 mm is output to a lens switching signal generator 51. The switching signal generator 51 drives the switching mechanism 52 via the driving circuit 45,
The converging lens 5 is moved to a use position. The reason for this is shown in FIG.
This will be described with reference to FIG. FIG. 9 is a top view of the structure of the optical actuator including the focus actuator 13 equipped with the converging lenses 5 and 42 according to the present invention and the lens switching mechanism 52 as viewed from the direction of the disk 7. As described above, in the optical actuator, the converging lenses 5 and 42 are mounted on the disk-shaped movable body 56 and can be moved by the focus actuator 13 along the rotation axis 54 in the focus direction perpendicular to the disk. Also, the movable body 56 is a shaft 5
The two converging lenses 5 and 42 are configured to be rotatable around four centers and switchable. FIG. 9A shows the case where the converging lens 5 for the substrate thickness of 1.2 mm is located at the position where it is used, and FIG. 9B shows the case where the converging lens 42 for the substrate thickness of 0.6 mm is located at the position where it is used. I have. However, since the friction between the movable body 56 that slides in the focus direction along the rotating shaft 54 and rotates about the rotating shaft and the rotating shaft 54 is not zero, FIGS. The movable body stops at an irregular position which is an intermediate position of 9b. At this time, since the light beam incident from the back side of the paper in FIG. 9 is blocked by the movable body 56, not only signal recording / reproduction but also focus control cannot be performed. At the time of start-up or the like performed only after the power is turned on to the apparatus, it is not known which of the converging lenses 5 and 42 is located at the operating position of the movable body 56 when the apparatus is turned on. Further, it is possible that an external force such as vibration or impact is applied to the device, and the movable body 56 is located at an irregular position where operation is not possible as shown in FIG. 9c. In any of these states, the operation of unconditionally moving the converging lens 5 to the use position is executed so that the apparatus start-up operation can be reliably executed. Subsequently, the microcomputer 48 transmits a DMON signal to the drive circuit 49, and the drive circuit 49 drives the motor 6 to rotate the disk 7 at a predetermined rotation speed. Further, the microcomputer 48 outputs an ON command to the drive circuit 46, and the drive circuit 46
The semiconductor laser 1 is caused to emit light with a predetermined optical power. Subsequently, the microcomputer 48 outputs a focus control ON command to the switch 50 to operate the focus control. Here 65
The reason why the 780 nm semiconductor laser 1 is operated instead of the 0 nm semiconductor laser 43 will be described. Disk 7
This is because, when the disk is mounted on the apparatus, it is not possible to determine at this time which disk is mounted among a plurality of types of disks. 650nm in this state
When the semiconductor laser 43 is used, if the disk A is mounted, data already recorded on the disk A is destroyed by the optical characteristics of the disk A described above. In order to avoid such a situation, the semiconductor laser 1 having a wavelength of 780 nm is used at the time of startup. In this embodiment, for the sake of simplicity, the focus control is operated on the semiconductor laser 1 after the rotation of the motor 6 is started.
Then, after the focus control is operated, there is no problem even if the rotation of the motor 6 is started.

When the focus control operates, the microcomputer 4
8 starts monitoring the output of the address reading circuit 21. If the loaded disk is the disk A, the address reading circuit 21 can read the address formed on the disk, and should output the address value periodically. On the other hand, when the disk B is mounted, as described above,
Has a higher density of information recorded thereon than that of the disc A. The recording operation can be performed only by using the light beam having the wavelength of 650 nm and the converging lens 42 for the base material thickness of 0.6 mm, and the already recorded signal can be read out. Is configured. Therefore, disk B
Is attached, the address reading circuit 21 cannot read the address, and the address value is not output to the microcomputer 48.

The microcomputer 48 includes the address reading circuit 21
It is observed whether a plurality of addresses are output within a predetermined time. If the address is output within a predetermined time, it is determined that the disk A is mounted. If the address is not output within the predetermined time, it is determined that the disk B has been mounted, and the microcomputer 48 performs the operation described below.

The microcomputer 48 outputs an OFF command to the drive circuit 46 to stop the light emission of the semiconductor laser 1, and then issues a command signal for switching to the converging lens 42 for a substrate thickness of 0.6 mm to generate a lens switching signal. Output to the container 51. The switching signal generator 51 drives the switching mechanism 52 via the drive circuit 45 to move the converging lens 42 to the use position. Thereafter, the microcomputer 48 outputs an ON command to the drive circuit 47, and the drive circuit 47 causes the 650 nm semiconductor laser 44 to emit light with a predetermined optical power. Subsequently, the microcomputer 48 controls the focus.
An ON command is output to the switch 50 to operate the focus control. Thereafter, similarly, the microcomputer 48 starts monitoring the output of the address reading circuit 21. Since the disk B is mounted, the address reading circuit 21
Thus, the output is output at a predetermined interval, and the start operation ends. After the start-up operation is completed, the microcomputer 48 determines the type of the loaded disk (disk A or disk B), the convergent lens used (convergent lens 5 or 42), and the semiconductor laser used (semiconductor laser 1 or 43). Is stored in the memory 53. The reason will be described later.

Next, the sleep operation will be described. The sleep operation is performed when various operation commands are not issued from the outside to the device for a certain period of time to reduce power consumption,
The operation of the apparatus is temporarily stopped based on a sleep command from the outside, and when a command is issued from the outside, the apparatus immediately returns to perform an operation based on the command. Before entering the sleep operation, the microcomputer 48 determines the type of the loaded disk (disk A or disk B), the convergent lens used (convergent lens 5 or 42),
The semiconductor laser used (semiconductor laser 1 or 4)
Information such as 3) is stored and stored in the memory 53. In the sleep operation, the microcomputer 48 outputs a focus OFF command to the switch 50, the switch 50 is released to stop the focus control operation, and then the microcomputer 48 uses one of the drive circuits 46 and 47 for the drive circuit which is being used. OFF
A command is output, and the light emission of the semiconductor laser 1 or 43 is stopped. Further, the microcomputer 48 turns off the drive circuit 49 as well.
When a command is output and the rotation of the motor 6 is stopped, a sleep operation is performed. In this state, since the focus actuator 13 and the motor 6 are stopped, power consumption can be reduced.

Next, the operation of returning from sleep will be described. When a command is issued from the outside to the device, the microcomputer 48
Suspends the sleep operation and performs a return operation from the sleep. First, the microcomputer 48 retrieves the information of the disc type, the convergent lens, and the semiconductor laser used in the apparatus immediately before the sleep, which are stored in the memory 53, immediately before the sleep.
Then, first, a switching signal to the convergent lens used immediately before sleep is output to the lens switching signal generator 51 unconditionally. This is because an external force such as vibration or impact is applied to the device during the sleep operation, the position of the movable body 56 moves, and the movable body 56 moves or stops at an irregular position, or switches to the convergent lens side not specified for use. This is a measure for preventing an abnormal state that occurs when the error has occurred. Thereafter, the microcomputer 28 outputs an ON command to the drive circuit 49 to rotate the motor 6 and transmits an ON command to the drive circuit for driving the same semiconductor laser stored in the memory 53 and used immediately before sleep. Then, the same semiconductor laser as used immediately before sleep is emitted. Thereafter, the microcomputer 48 outputs a focus control ON command to the switch 50 to operate the focus control, and the operation of returning from sleep is completed. As described above, before the returning operation from the sleep operation is started, the switching operation to the convergent lens used immediately before the sleep operation is first performed, so that an external force such as vibration or impact is applied to the device during the sleep operation, and the movable body 56 Even if the position moves, it is possible to smoothly return from sleep.

In this embodiment, not only the focus control but also the sleep in which the operation of the motor 6 is stopped has been described. However, the motor 6 is operated in the focus sleep operation in which only the focus control and the operation of the semiconductor laser are stopped. Similarly, it is needless to say that the same effect can be obtained by operating the semiconductor laser and the focus control after first performing the switching operation to the convergent lens unconditionally.

Finally, a description will be given of the recovery processing when some abnormality occurs during the operation of the apparatus. Actual devices are often used in various harsh environments, and various errors are expected to occur in the devices.
One of these is external vibration or impact. As described above, in this apparatus, the focus control is operated to keep the convergence state of the light beam on the disk 7 constant. However, in general, the thrust of the focus actuator is finite. When strong vibration or shock is applied from the outside, a focus jump occurs. When a focus jump occurs, the light beam no longer maintains a predetermined convergence state on the disk 7, so that recording and reproduction of signals on the disk 7 become impossible.
An error occurs. The recovery processing procedure when such an error occurs will be described.

This apparatus is provided with a detection function for detecting a focus jump by itself. The microcomputer 48 has the switch 5
0 is short-circuited, and it is monitored whether the address value is continuously output from the address reading circuit 21 at a predetermined cycle or less while the focus control is in operation. When the focus control is operating normally, the addresses are periodically provided on the disk 7 as described above.
An address value read periodically from the address reading circuit 21 is output to the microcomputer 48. If a focus jump occurs, the address output from the address reading circuit 21 is no longer output. Therefore, the address value output from the address reading circuit 21 is longer than a predetermined period (for example, 5 times of the normal address output cycle).
The focus jump is detected by setting a determination condition that the output is not continuously performed (up to 10 times or longer). When the focus jump is detected, the microcomputer 48 outputs a focus control OFF command to the switch 50, and the switch 50 is released to stop the focus control. Thereafter, the microcomputer 48 first stores the memory 5
The information on the type of disc mounted on the apparatus, the convergent lens used, and the semiconductor laser stored in the apparatus 3 is called out. First, the lens switching signal generator 51 is unconditionally
The switching signal to the convergent lens used for the above is output. This is because, when an external force such as vibration or impact is applied to the device and an error occurs, the position of the movable body 56 is moved by the external force, and moved or stopped to an irregular position, or the use was not designated. This is a measure for preventing an abnormal state occurring when the lens is switched to the convergent lens side. Thereafter, the microcomputer 48 outputs a focus control ON command to the switch 50 to operate the focus control, and the operation of returning from the focus jump is completed. As described above, before the returning operation from the focus jump is started, an external force such as vibration or impact is applied by first performing a switching operation to the convergent lens used, so that even when the position of the movable body 56 moves, It is possible to return from the focus jump.

In the present embodiment, when returning from the focus jump, the return processing is performed by deactivating only the focus control. However, after the focus control is stopped, the emission of the semiconductor laser is stopped, or the motor 6 is further stopped. Even if the rotation is stopped and the starting operation is performed again in the reverse order, there is no problem. In this embodiment, only the focus jump has been described. However, other errors, such as an abnormal stop of the motor 6 or a data read error, may be performed immediately before the return operation from the focus jump. It goes without saying that a similar effect can be obtained by performing the switching operation to the used convergent lens before performing the switching operation.

[0031]

As described above, according to the present invention, after a switching operation for switching from a plurality of converging lenses to a specific converging lens is performed, a starting operation of the apparatus, a returning operation from an abnormal state,
By re-activating the focus control, returning from the device sleep state, and returning from the focus sleep state, the type of media attached immediately before the sleep or abnormal state, and the convergent lens used By providing a means for storing the light and the light source, by switching to the convergent lens and the light source according to the storage and then performing the operation of returning from the abnormal state or sleep, the position of the convergent lens is moved by external force or the like, Alternatively, even in the case of switching, it is possible to use the correct converging lens to perform a start-up operation of the apparatus, a return operation from an abnormal state, a re-operation of focus control, a return operation from the apparatus sleep state, and a return operation from the focus sleep. is there.

Also, at the time of starting the apparatus, the light source having the wavelength of 780 nm is first operated so that 650 nm
Thus, a safe apparatus start-up operation can be performed on a medium having an increased absorption rate without damaging recorded data.

[Brief description of the drawings]

FIG. 1 is a block diagram according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a defocus of an astigmatism method and a light beam on a detector.

Fig. 3 Structure diagram of CD media

FIG. 4 is a structural diagram of a DVD medium.

FIG. 5 is a structural diagram of an optical head used in an embodiment of the present invention.

FIG. 6 is a structural diagram of a disk used in an embodiment of the present invention.

FIG. 7 is an enlarged structural view of a disk used in an embodiment of the present invention.

FIG. 8 is a diagram showing the reflectance vs. wavelength characteristics of a CD-R medium.

FIG. 9 is a top view of an actuator used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 780 nm semiconductor laser 2 Collimator lens 3 Polarization beam splitter 4 λ / 4 plate 5 Convergent lens for 1.2 mm 6 Disk motor 7 Disk 8 Photodetector 9 Differential amplifier 10 Phase compensation circuit 11 Gain compensation circuit 12 Drive circuit 13 Focus actuator Reference Signs List 15 detection lens 16 cylindrical lens 17 adder 18 adder 19 adder 21 address reading circuit 42 converging lens for 0.6 mm 43 650 nm semiconductor laser 48 microcomputer 50 switch 51 switching signal generator 52 lens switching mechanism 54 rotating shaft 56 movable body

Claims (22)

[Claims] 1. A plurality of converging means for converging a light beam on said information carrier for recording or reproducing a signal on or from a plurality of types of information carriers having different substrate thicknesses; An optical recording / reproducing apparatus having a switching means for arbitrarily selecting one to be switched, operating the switching means to switch from a plurality of the convergence means to a specific convergence means, and then starting the apparatus An optical recording / reproducing apparatus for starting operation. 2. A plurality of types of information carriers having different substrate thicknesses are substantially
A first information carrier having a base material thickness of 1.2 mm and a second information carrier having a base material thickness of approximately 0.6 mm, and a first convergence means suitable for the first information carrier as convergence means Means, said second
And a second convergence means suitable for the information carrier.
An optical recording / reproducing apparatus as described in the above. 3. A method for providing a means for identifying a base material thickness of a mounted information carrier, operating a switching means so as to switch to a convergence means suitable for the mounted information carrier, and then performing a starting operation. The optical recording / reproducing apparatus according to claim 1, wherein: 4. A plurality of converging means for converging a light beam on said information carrier in order to record or reproduce a signal on or from a plurality of types of information carriers having different substrate thicknesses; An optical recording / reproducing apparatus having switching means for arbitrarily selecting one to be performed, providing an abnormality detecting means for detecting an abnormal state of the apparatus, and stopping the operation of the apparatus when an abnormal state is detected; An optical recording / reproducing apparatus, comprising: operating the switching means so as to switch from a plurality of convergence means to a specific convergence means; and thereafter restarting the operation. 5. A plurality of types of information carriers having different substrate thicknesses are substantially
A first information carrier having a base material thickness of 1.2 mm and a second information carrier having a base material thickness of approximately 0.6 mm, wherein the first convergence means suitable for the first information carrier as convergence means Means, said second
And a second convergence means suitable for the information carrier.
An optical recording / reproducing apparatus as described in the above. 6. A storage means for storing at least the type of information carrier attached to the apparatus when an abnormality is detected, and a switching means for switching to a convergence means suitable for the information carrier according to the storage of said storage means. 5. The optical recording / reproducing apparatus according to claim 4, wherein the operation is restarted after the operation. 7. A plurality of converging means for converging a light beam on said information carrier for recording or reproducing signals on a plurality of types of information carriers having different substrate thicknesses, and said converging means is substantially equivalent to said information carrier. A moving unit that moves in a vertical direction, a convergence state detecting unit that detects a convergence state of the light beam on the information carrier, and the light unit that drives the moving unit in accordance with an output of the convergence state detection unit to generate the light beam. An optical recording / reproducing apparatus having a focus control means for controlling a convergence state on an information carrier so as to be always substantially a predetermined convergence state, and a switching means for arbitrarily selecting and switching one of a plurality of convergence means to be used. An abnormality detecting means for detecting an abnormality of the focus control means, and when an abnormality is detected, the operation of the focus control means is stopped and a plurality of the convergence means are switched to a specific convergence means. After since the switching means is operated to switch, the optical recording and reproducing apparatus characterized by re-starting the operation again the focus control means. 8. A plurality of types of information carriers having different substrate thicknesses are substantially
A first information carrier having a base material thickness of 1.2 mm and a second information carrier having a base material thickness of approximately 0.6 mm, wherein the first convergence means suitable for the first information carrier as convergence means Means, said second
And a second convergence means suitable for the information carrier of (1).
An optical recording / reproducing apparatus as described in the above. 9. A storage means for storing at least a type of information carrier attached to the apparatus at the time of detecting an abnormality, and a switching means for switching to a convergence means suitable for the information carrier according to the storage of said storage means. 8. The optical recording / reproducing apparatus according to claim 7, wherein the operation is restarted after the operation. 10. A plurality of converging means for converging a light beam on said information carrier for recording or reproducing signals on a plurality of types of information carriers having different substrate thicknesses, and a plurality of said converging means. An optical recording / reproducing apparatus having a switching means for arbitrarily selecting one of the operations to be performed, comprising a sleep means for performing a sleep for temporarily stopping the operation of the apparatus in order to reduce power consumption; An optical recording / reproducing apparatus, comprising: operating the switching means so as to switch from a plurality of the convergence means to a specific convergence means when returning from sleep and returning from sleep, and then performing a return operation of the apparatus. . 11. A plurality of types of information carriers having different substrate thicknesses are a first information carrier having a substrate thickness of approximately 1.2 mm and a second information carrier having a substrate thickness of approximately 0.6 mm. The optical recording / reproducing apparatus according to claim 10, further comprising a first convergence unit suitable for the first information carrier and a second convergence unit suitable for the second information carrier as convergence units. 12. A storage means for storing the type of the information carrier attached to the apparatus immediately before the operation of the sleep means, wherein the operation of the sleep means is stopped and when returning from the sleep mode, the storage means is provided in accordance with the storage of the storage means. 11. The optical recording / reproducing apparatus according to claim 10, wherein after the switching means is operated so as to switch to the convergence means suitable for the information carrier, a return operation of the apparatus is performed. 13. A plurality of converging means for converging a light beam on said information carrier for recording or reproducing signals on a plurality of types of information carriers having different base material thicknesses, and said converging means is substantially equivalent to said information carrier. A moving unit that moves in a vertical direction, a convergence state detecting unit that detects a convergence state of the light beam on the information carrier, and the light unit that drives the moving unit in accordance with an output of the convergence state detection unit to generate the light beam. An optical recording / reproducing apparatus having a focus control means for controlling a convergence state on an information carrier so as to be always substantially in a predetermined convergence state, and a switching means for arbitrarily selecting and switching one of a plurality of convergence means to be used. A sleep unit that performs sleep to temporarily stop the operation of the focus control unit to reduce power consumption, and to stop the operation of the sleep unit when returning from sleep. After the switching means to switch to a specific converging means from by operating of several said converging means, an optical recording and reproducing apparatus characterized by operating the focus control unit again. 14. A plurality of types of information carriers having different substrate thicknesses are a first information carrier having a substrate thickness of approximately 1.2 mm and a second information carrier having a substrate thickness of approximately 0.6 mm. The optical recording / reproducing apparatus according to claim 10, further comprising a first convergence unit suitable for the first information carrier and a second convergence unit suitable for the second information carrier as convergence units. 15. A storage means for storing the type of the information carrier attached immediately before the operation of the sleep means, wherein the operation of the sleep means is stopped and when returning from sleep, the information carrier corresponding to the storage of the storage means is provided. 14. The method according to claim 13, wherein the switching means is operated so as to switch to the convergence means suitable for the body, and then the focus control means is operated again.
An optical recording / reproducing apparatus as described in the above. 16. A plurality of light sources having different wavelengths for recording or reproducing signals on a plurality of types of information carriers having different optical reflection / absorption characteristics with respect to wavelengths, and light beams from the light sources are placed on the information carrier. An optical recording / reproducing apparatus having convergence means for converging and switching means for arbitrarily selecting and switching one of a plurality of light sources to be used, wherein the plurality of light sources are switched to a specific light source. An optical recording / reproducing apparatus, characterized in that a start-up operation of the apparatus is started after operating the switching means. 17. A plurality of types of information carriers having different optical reflection / absorption characteristics with respect to wavelength, a first information carrier having high reflection / low absorption at approximately 780 nm wavelength and low reflection / high absorption at approximately 650 nm wavelength. Second with high reflection / low absorption at approximately 650nm wavelength
A light source that emits a light beam having a wavelength of approximately 780 nm suitable for the first information carrier, and a light beam having a wavelength of approximately 650 nm suitable for the second information carrier. The optical recording / reproducing apparatus according to claim 16, further comprising a second light source that emits light. 18. A wavelength of approximately 780 nm suitable for the first information carrier.
18. The optical recording / reproducing apparatus according to claim 17, wherein the switching means is operated so as to switch to the first light source that emits the light beam, and then the starting operation is performed. 19. A plurality of light sources having different wavelengths for recording or reproducing signals on a plurality of types of information carriers having different optical reflection / absorption characteristics with respect to wavelengths, and light beams from the light sources are placed on the information carrier. In an optical recording / reproducing apparatus having converging means for converging and switching means for arbitrarily selecting and switching one of a plurality of light sources to be used, operation of the apparatus is temporarily stopped to reduce power consumption. A sleep unit for performing a sleep operation, wherein the operation of the sleep unit is stopped and the switching unit is operated so as to switch from a plurality of the light sources to a specific light source when returning from sleep; An optical recording / reproducing apparatus. 20. A plurality of types of information carriers having different optical reflection / absorption characteristics with respect to wavelength, the first information carrier having high reflection / low absorption at approximately 780 nm wavelength and low reflection / high absorption at approximately 650 nm wavelength. Second with high reflection / low absorption at approximately 650nm wavelength
A light source that emits a light beam having a wavelength of approximately 780 nm suitable for the first information carrier, and a light beam having a wavelength of approximately 650 nm suitable for the second information carrier. The optical recording / reproducing apparatus according to claim 19, further comprising a second light source that emits light. 21. A storage means for storing the type of the information carrier attached to the apparatus immediately before the operation of the sleep means, wherein the operation of the sleep means is stopped and when returning from the sleep mode, the storage means is provided in accordance with the storage of the storage means. 20. The optical recording / reproducing apparatus according to claim 19, wherein after operating the switching means so as to switch to a light source suitable for the information carrier, the apparatus performs a return operation. 22. A storage device for storing a light source operating immediately before the operation of the sleep device, wherein the operation of the sleep device is stopped, and when returning from sleep, the light source is switched to a light source corresponding to the storage of the storage device. 20. The optical recording / reproducing apparatus according to claim 19, wherein the operation of returning the apparatus is performed after the operation of the means.