JPH04362530A - Optical disk drive device - Google Patents

Abstract

PURPOSE:To access the respective optical disks of a CAV system and a CLV system with simple circuit constitution, CONSTITUTION:In an optical disk device, a cartridge identification sensor 113 reads the identifier of the cartridge and discriminates the type of the optical disks. When the loaded optical disk is detected to be the CLV system, the other axis of a galvano-mirro 34 which is not driven is reciprocally driven within a prescribed angle. The driving direction, a reciprocal range and speed are decided at first. The driving method is previously and fixedly set in accordance with the track position of the optical disk in the radial direction. A beam scan voltage generation circuit 108 detects the actual manipulated variable of the mirror 34 in accordance with the driving method while scan voltage for driving the mirror 34 is generated. The moving speed of a laser beam on a track is set to be the linear speed of the CLV system in the prescribed range of one way and information is recorded and reproduced for the optical disk in the period.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc drive device.

0002

[Prior art] A cartridge containing an optical disc is
2. Description of the Related Art Cartridge-type optical disc devices, which can be optionally attached to and removed from an optical disc drive device, are often used.

[0003] Optical disc devices use CAV (Conn) as a basic speed control method when rotating an optical disc.
Stunt Angular Velocity:
(constant rotation angle) method and CLV (Constant L
There is an inear velocity (constant linear velocity) method. In the CAV method, the optical disk is always rotated at a constant speed, and in the CLV method, the rotation speed is changed depending on the track position to be accessed, and the linear speed at which the laser spot passes over the track is kept constant.

These two systems are generally not compatible because the sector arrangement of the optical disc and the control circuit of the optical disc drive device are different.

[0005] A method is known that improves this point and allows a CAV system optical disc drive device to also access a CLV system optical disc. In this method, when a CLV type optical disk is loaded, instead of rotating the optical disk at a constant speed, the frequency of a clock signal for reading/writing data bit by bit is changed.

[0006] In this method, the clock signal must be variable over a wide frequency range, such as 2.5 to 5 MHz, and must be stable with no frequency fluctuations.

By the way, in order to change the frequency of the clock signal as described above, P
This changes the operating frequency of the LL (Phase Locked Loop) circuit.

[0008] There are two types of PLL circuits: an analog type and a digital type. In the case of analog system, VCO (Vo
ltage Controlled Oscill
ator) circuit. However, in this case, it is difficult to vary the frequency over such a wide frequency range with one VCO circuit. Therefore, a plurality of circuits must be provided, making the circuit complicated.

On the other hand, in the case of a digital system, a high frequency original signal is generated and the high frequency is divided by various integer ratios. In this case, if you try to obtain an arbitrary frequency between 2.5 and 5 MHz as described above, for example, 2
A high frequency signal such as 000 GHz is required. However, with ordinary digital circuits, it is difficult to generate or divide such high frequency signals.

0010

[Problem to be solved by the invention] As described above, conventionally, 1
If one optical disk drive device were to access each of the CAV and CLV optical disks, there was a problem in that the circuit configuration would be complex and difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide an optical disk drive device that has a simple circuit configuration and can access CAV and CLV optical disks.

0012

[Means for Solving the Problem] To this end, the present invention provides a CAV system optical disc drive device that rotates an optical disc at a constant speed, and when a CLV system optical disc is loaded, the irradiation position of a laser beam on the optical disc is changed. By periodically reciprocating within a certain range along the track and adjusting the direction, speed and range of movement during the reciprocating according to the position in the radial direction of the optical disc, the The moving speed of the laser beam is set to the linear velocity of the CLV method,
The present invention is characterized in that information recording and reproducing operations are performed on the optical disc during the period when the linear velocity of the CLV method is reached.

[0013]

[Operation] Each CAV system and CLV system optical disk can be accessed, and in this case, as in the past, PLL
There is no need to change the operating frequency of the circuit, and the irradiation direction of the laser beam only needs to be reciprocated within a certain range.
The device can be configured with a relatively simple circuit.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration diagram of an optical disk drive device according to an embodiment of the present invention. An operator can optionally install an optical disc cartridge (not shown) into this optical disc device. The optical disc 1 in the installed optical disc cartridge is driven by a spindle motor 2. An optical head 3 is disposed below one side of the optical disc 1 . This optical head 3 is driven in the radial direction of the optical disc 1 by a coarse motor 4. Although not shown, a linear encoder that detects the moving position of the optical head 3, a sensor that reads a cartridge identifier formed on the case body of the optical disk cartridge, and the like are provided.

FIG. 2 shows a diagram of the internal structure of the optical head 3. As shown in FIG. In the figure, laser light emitted from a semiconductor laser 31 passes through a coupling lens 32 and enters a beam splitter 33. The incident light is reflected by the beam splitter 33, further reflected by the galvano mirror 34, passes through the aperture lens 35, and is irradiated onto the optical disc 1.

The reflected light from the optical disk 1 returns to the beam splitter 33 via a path opposite to that described above. This incident light passes through the beam splitter 33, passes through the condenser lens 36, and enters the light receiving section 37. The light receiving section 37 outputs a tracking error signal, a focus error signal, and a reproduction signal of recorded information.

Although not shown, the galvanometer mirror 34 is supported by two orthogonal axes. and,
A two-axis actuator is provided that rotates the galvano mirror 34 around its two axes and moves the laser spot on the optical disc 1 in the radial direction of the optical disc 1 and in the tangential direction of the track. Further, a sensor for detecting the rotation angle of the galvanometer mirror 34 is provided. Furthermore, an actuator for moving the diaphragm lens 35 in the optical axis direction is provided.

FIG. 3 shows a block diagram of this optical disc device. In the figure, a focus error signal output from the light receiving section 37 is input to a focusing control circuit 101, and its output is input to an amplifier 102. The output of the amplifier 102 drives an actuator 103 that drives the aperture lens 35.

Further, the tracking error signal output from the light receiving section 37 is input to a tracking servo control circuit 104, and the output thereof is input to an amplifier 105. The output of the amplifier 105 drives one axis of a two-axis actuator 106 that drives the galvanometer mirror 34. An output signal from a sensor 107 that detects the rotation angle of the galvanometer mirror 34 is input to a beam scanning voltage generation circuit 108. Its output is amplifier 109
The output of the amplifier 109 drives the other axis of the two-axis actuator 106.

The output of the seek control circuit 110 is output from the amplifier 1.
11, and its output drives the coarse motor 4. A detection signal from a linear encoder 112 that detects the position of the optical head 3 and a detection signal from a cartridge identifier sensor 113 that reads a cartridge identifier on an optical disc cartridge case body are input to a microcomputer 114.

The microcomputer 114 sends control signals to the focusing control circuit 101, tracking servo control circuit 104, beam scanning voltage generation circuit 108, seek control circuit 110, spindle motor drive circuit 115, and data recording/reproducing section 116, respectively. is being output. A spindle motor drive circuit 115 drives the spindle motor 2. The reproduction signal output from the light receiving section 37 is input to the data recording/reproducing section 116. The data recording/reproducing section 116 drives the semiconductor laser 31 and is connected to the host device.

With the above configuration, the operation of the optical disc drive device of this embodiment will now be explained. As shown in FIG. 4, this optical disk device monitors attachment of an optical disk cartridge when the device power is turned on (process 201). Assuming that the optical disc cartridge is now installed by the operator (Y in process 201), the spindle motor drive circuit 115 is operated to drive the spindle motor 2. In this embodiment, the spindle motor 2 is always rotated at a constant speed (process 202). Next, the optical head 3 is moved to a predetermined home position by the seek control circuit 110 and the amplifier 111 while the moving position is detected by the linear encoder 112 (process 203).

Further, while driving the semiconductor laser 31 to emit laser light, the focusing control circuit 1
01 and the control operation of the tracking servo control circuit 104 is started. That is, the laser light emitted from the semiconductor laser 31 is irradiated onto the optical disc 1, and the reflected light is detected by the light receiving section 37. At this time, the light receiving section 37
outputs a focusing error signal and a tracking error signal. Focusing control circuit 101 outputs a predetermined control signal based on the focusing error signal. This control signal causes the actuator 103 to operate and the aperture lens 35 to be driven. As a result, focusing control is executed to form a predetermined laser spot on the optical disc. Further, the tracking servo control circuit 104 outputs a predetermined control signal based on the tracking error signal. This control signal operates the two-axis actuator 106 to drive one axis of the galvano mirror 34. As a result, predetermined tracking control is executed to cause the laser spot to follow the track position (process 204).

Thereafter, reception of read/write commands from the host device is monitored (loop N of process 205). Now, if a read or write command is received (Y in process 205), the optical head 3 is driven to a track position corresponding to the sector designated by the coarse movement seek, that is, the command (process 206).

By the way, the optical disc cartridge has
A cartridge identifier is formed at a certain position on the case body. This cartridge identifier is made up of a plurality of holes, and depending on the presence or absence of each hole, various specifications of the optical disc, such as whether the built-in optical disc is a CAV system or a CLV system, are displayed.

Here, the optical disc drive apparatus reads the cartridge identifier using the cartridge identifier sensor 113 (process 207), and determines the type of the optical disc loaded (process 208). Now, assume that the cartridge identifier indicates the CAV system. In this case (Y in process 208), the ID information of each sector of the optical disc 1 is detected by a known operation. That is, the light receiving section 37 detects the reflected light from the track and outputs a reproduction signal. Based on the reproduction signal, the data recording/reproducing section 116
The ID information of each sector is reproduced (process 209).

When a sector to be accessed is found based on the ID information, the data recording/reproducing section 116 performs a read/write operation on that sector. That is, in the case of a read operation, recorded data in a predetermined sector is reproduced and output to the host side. Furthermore, in the case of a write operation, the semiconductor laser 31 is driven based on data input from the host side, and the laser beam is modulated. As a result, data is recorded in a predetermined sector (processing 2
10). Thereafter, the process returns to monitoring reception of the next command (proceeding to process 205).

Next, assume that a CLV type optical disc is loaded. In this case (N in process 208), the other axis of the galvano mirror 34 that was not driven in the above is reciprocated within a predetermined angle, but first, its driving direction, reciprocation range, and speed are determined (process 211 ). Note that the driving direction refers to which side is driven first when reciprocating to both sides around a certain position. These driving methods are fixedly set in advance according to the track position of the optical disc 1 in the radial direction.

The beam scanning voltage generating circuit 108 uses the sensor 107 to drive the galvano mirror 3 according to the above-mentioned driving method.
While detecting the actual operation amount of 4, a scanning voltage for driving the galvano mirror 34 is generated. amplifier 10
9 amplifies the scanning voltage to drive a two-axis actuator 10.
6 is driven (process 212).

The scanning voltage is a signal that is repeatedly output at a constant period, and FIG. 5(a) shows the voltage waveform for one time. The voltage waveform of this scanning voltage differs depending on the track position to be accessed.

For example, assume that the track position to be accessed is at the outermost circumference of the optical disc 1. In this case, as shown in the waveform W1 in the figure, the voltage value is always zero and changes from a constant positive voltage to a constant negative voltage only during a certain period T1. As a result, the galvanometer mirror 34 rotates,
A laser spot on the optical disc 1 reciprocates within a certain range in the tangential direction of the track. At this time, tracking control is automatically executed and the laser spot moves along the track. In this case, the laser spot moves a certain distance on the track in the same direction as the rotational direction of the optical disc 1, as shown by the moving direction M1 in FIG. 6, within the certain period T1.

FIG. 3B shows the relative speed between the laser spot and the track. In this case, as shown by the speed V1, the speed decreases at the beginning of the fixed period T1, and then becomes constant during the fixed period T2. Then, after the above-mentioned fixed period T1, it decreases once and returns to its original state.

In this embodiment, the above constant speed is defined as v,
The linear velocity of the CLV optical disc 1 installed is a
, the radial track position of the optical disc 1 is r, and the angular velocity of the spindle motor 2 is θ, then v=(a/
It is set so that the following relationship holds true: r)-r·θ. This results in
The constant speed v is made equal to a predetermined linear speed when accessing the CLV type optical disc 1.

As shown in FIG. 5(a), the voltage level of the scanning voltage changes with waveforms W2, W3, W4, and W5 as the track position to be accessed moves toward the inner circumference. That is, the scanning amplitude of the laser beam is narrowed as it approaches the center of the track range to be accessed, and no scanning occurs at the central position. In addition, further toward the inner circumference, the scanning direction is reversed, and the scanning amplitude is made wider again as it moves toward the inner circumference. At the innermost track position, the laser spot moves in the same range in the opposite direction to the moving direction M1, as shown by the moving direction M5 in FIG. At this time, the relative speed between the laser spot and the track is T1 for a certain period of time, as shown by the speed V5 in FIG. 5(b).
It rises at the beginning of , reaches a constant speed for a certain period of time T2, and then rises once and returns to the original speed.

[0036] Within a certain period T2, the relative speed between the laser spot and the track is constant regardless of the track position. The microcomputer 114 outputs a read/write timing signal in synchronization with this fixed period T2, as shown in FIG. 5(c). The data recording/reproducing section 116 operates at this timing.

[0037] This optical disc device roughly seeks the optical head 3 to a predetermined track position in accordance with the read/write command that has been received. Then, ID information is detected at that track position and a sector to be accessed is searched for (processing 213). When a sector to be accessed is found, a read/write operation is performed on the sector. Note that if the sector length is longer than the distance that the laser spot moves on the track during the fixed period T2, reading/writing within one sector is divided into a plurality of times by a fixed distance. In this case, since the operation is performed once for one revolution of the optical disc 1, access to one sector is completed in multiple revolutions (processing 214).

When the access operation is completed, the reciprocating drive of the galvanometer mirror 34 for scanning the laser beam is stopped (process 215), and the process returns to receiving the next command (process 205).

As described above, in this embodiment, when a CLV type optical disk is loaded in an optical disk drive device that rotates the optical disk 1 at a constant speed,
The laser spot on the optical disk is periodically moved back and forth within a predetermined range along the track, and within a certain range in one direction,
The moving speed of the laser spot is made equal to the linear velocity of the CLV method, and during this period, information recording/reproducing operations are performed on the optical disk.

[0040] This makes it possible to access each optical disc of the CAV system and the CLV system. Furthermore, in this case, there is no need to use a PLL circuit as in the prior art, and the irradiation direction of the laser beam only needs to be reciprocated within a certain range, so the device can be configured with a relatively simple circuit.

By the way, in order to continuously record and reproduce a large amount of data on the optical disc 1, as shown in FIG.
162 may be provided. In this case, when receiving data to be recorded from the host device, the write clock signal WC1 is input to the recording buffer memory 1161, and the data to be recorded is temporarily stored. When recording data, the read clock signal RC1 is intermittently inputted corresponding to periodic recording periods, and the data is sequentially read out and recorded on the optical disc 1.

Furthermore, when reproducing data from the optical disc 1, the write clock signal WC2 is inputted to the reproducing buffer memory 1162 in synchronization with the cycle in which the data is reproduced, and the reproduced data is sequentially stored. Then, when the reproduction is completed, the read clock signal RC2 is inputted, and all the stored data are collectively sent to the host side.

In this way, the recording buffer memory 1161
By providing a playback device 1162, it is possible to exchange data with the host side all at once.

[0044] In the above-described embodiment, the case of a normal optical disc device was explained as an example, but it goes without saying that the present invention can be similarly applied to a magneto-optical disc device.

[0045]

As described above, according to the present invention, when a CLV type optical disk is loaded in a CAV type optical disk drive device that rotates an optical disk at a constant speed, the laser beam irradiation position on the optical disk can be changed. is periodically reciprocated within a predetermined range along the track, and during the period when the moving speed of the laser spot on the track reaches the linear velocity of the CLV method, information recording/reproducing operations are performed on the optical disc. Therefore, it is possible to access both CAV and CLV optical disks, and there is no need for a complicated PLL circuit as in the past, and it is only necessary to reciprocate the laser beam irradiation direction within a certain range, so it is relatively easy to access. It becomes possible to configure a device with a simple circuit.

[Brief explanation of the drawing]

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

FIG. 2 is a configuration diagram of an optical head.

FIG. 3 is a block configuration diagram of the optical disc drive device.

FIG. 4 is an operation flowchart of the optical disc drive device.

FIG. 5 is an explanatory diagram showing a laser beam scanning method using a galvano mirror.

FIG. 6 is an explanatory diagram showing the movement state of a laser spot on an optical disc.

FIG. 7 is a block configuration diagram of a data/recording/reproducing section in another embodiment.

[Explanation of symbols]

1 Optical disk 2 Spindle motor 3 Optical head 4 Coarse motor 31 Semiconductor laser 32 Coupling lens 33 Beam splitter 34 Galvano mirror 35 Stop lens 36 Condensing lens 37 Light receiving section 101 Focusing control circuit 102, 105, 109, 111 Amplifier 103
Actuator 104 Tracking servo control circuit 106 Two-axis actuator 107 Sensor 108 Beam scanning voltage generation circuit 110 Seek control circuit 112 Linear encoder 113 Cartridge identifier sensor 114 Microcomputer 115 Spindle motor drive circuit 116 Data recording/reproducing section

Claims (3)

[Claims] [Claim 1] Means for arbitrarily mounting an optical disc;
means for rotating the loaded optical disc at a constant speed;
An optical disk drive comprising means for irradiating a laser beam onto a track position of a rotating optical disk, and means for modulating the laser beam to record information on the optical disk or for receiving reflected light from the track to reproduce recorded information. In the apparatus, when the loaded optical disk is of a CLV type, a laser beam scanning means for periodically reciprocating the irradiation position of the laser beam on the optical disk within a certain range along a track; a scanning method adjusting means that adjusts the moving direction, speed, and range of the optical disk according to the radial position of the optical disk, and sets the moving speed of the irradiation position on the track to a CLV method linear speed within a certain range in one direction; , an optical disc access means for recording information on the optical disc or reproducing the recorded information during a period in which the moving speed becomes a linear velocity according to the CLV system. 2. A recording buffer memory for temporarily storing recording information inputted from the outside, and a sequential recording means for reading out a fixed amount of recording information stored in the recording buffer memory and recording it on an optical disc by the optical disc access means. and a playback buffer memory for temporarily storing the recorded information sequentially played back by the optical disc access means, and a playback information output means for outputting the recorded information stored in the playback buffer memory collectively to the outside. The optical disc drive device according to claim 1, characterized in that: 3. The laser beam scanning means includes a mirror that reflects the laser beam emitted from the light source and irradiates it onto the optical disk, and the mirror is driven on two axes to adjust the irradiation position of the laser beam to a radius of the optical disk. 2. The optical disk drive device according to claim 1, further comprising a mirror biaxial drive means for moving the mirror in both directions and in a tangential direction of the track.