JP2008204536A - Optical disc apparatus and recording / reproducing method thereof - Google Patents

Abstract

The present invention provides an optical disc apparatus having good recording and reproduction quality by optimizing a gain for amplifying an RF signal obtained from a received light signal of reflected light of each recording layer when the optical disc has a low reflectance, and recording and reproduction thereof It aims to provide a method.
The present invention relates to an objective lens for condensing laser light on an optical disk, a light receiving sensor for receiving reflected light from the optical disk and converting it into an electrical signal, an amplifier for amplifying the electrical signal, An S-shaped waveform was detected based on the amplified electrical signal, the number of layers of the optical disc 11 was determined based on the number of S-shaped waveforms, arbitrary address information of each layer was read, and address information of a certain layer could not be read In this case, a control means is provided for increasing the gain of the amplifier until the address information can be read from a certain layer, and storing the gain value when the address information is read for each layer.
[Selection] Figure 3

Description

  The present invention relates to an optical disk apparatus that records information by focusing a laser beam on a recording surface of an optical disk, and more particularly to an optical disk apparatus that records or reproduces information on a low-reflection optical disk having a plurality of recording surfaces and a recording / reproducing method thereof. It is about.

As an external recording device of a personal computer, an optical disc device that records information on an optical disc that can be optically recorded on a rotating recording medium is generally used. Many types of optical disks are used, such as CDs, DVDs, and Blu-ray disks. Playback-only optical disks (CD-ROM) and recordable optical disks that can be recorded once (CD-R, DVD-R). , DVD + R), and rewritable optical discs (CD-RW, DVD-RW, DVD + RW, DVD-RAM) that can be recorded multiple times. Moreover, in order to increase the recording capacity of these optical discs, two-layer optical discs having two recording layers have been proposed, and some of them have been put into practical use. In order to accurately perform the recording / reproducing operation on these various recording media, the optical disc apparatus needs to be operated in a state suitable for each medium. Therefore, in the optical disc apparatus, it is determined which type of the recording medium is inserted into the apparatus, and the apparatus is set in a state in which the inserted medium can be recorded and reproduced according to the determination content. It has a function. For example, there is a method for discriminating these optical discs (for example, Patent Document 1).
JP 2003-30830 A

  The conventional technology relates to an optical disc inserted into an optical disc apparatus, focusing on an area where address information of the optical disc is present, reading address information on an information recording surface, and relating to a layer on the recording surface of the optical disc from the read information. Information is acquired, and when there are two or more layers on the recording surface, the information is moved to the first layer and information about the optical disc is acquired.

  However, in a phase change type optical disc that can be recorded a plurality of times, the reflectivity decreases as light is absorbed by the phase change film, making it difficult to discriminate the optical disc based on the reflected light. There was a problem that could not be read.

  Further, with respect to the optical disk device before the release of the newly developed optical disk, there is a problem that various settings necessary for recording / reproducing of the optical disk cannot be performed and recording / reproduction cannot be performed because information on the optical disk is not provided.

  The present invention relates to an optical disc apparatus and a recording / reproducing method thereof with good optical disc recording or reproduction quality by optimizing a gain for amplifying an RF signal obtained from a received light signal of reflected light of each recording layer when the optical disc has a low reflectance. The purpose is to provide.

  In order to solve such a problem, the present invention provides an objective lens that focuses laser light on an optical disc, a light receiving sensor that receives reflected light from the optical disc and converts it into an electrical signal, an amplifier that amplifies the electrical signal, and an amplification S-shaped waveform is detected based on the detected electrical signal, the number of layers of the optical disc is determined based on the number of detected S-shaped waveforms, arbitrary address information of each layer is read, and address information of one layer cannot be read In this case, there is provided control means for increasing the gain of the amplifier until the address information can be read from one layer and storing the gain value when the address information is read for each layer.

  The present invention discriminates the number of layers of the optical disk based on the number of S-shaped waveforms detected from the focus error signal, reads arbitrary address information of each layer, and cannot read the address information of one layer. By increasing the gain of the amplifier until the address information can be read, the signal gain of the light receiving sensor can be optimized in a low-reflectance optical disk such as a phase change optical disk, so recording and reproduction are optimized for each recording layer of the optical disk. Thus, recording and reproduction quality can be improved.

  Also, by storing the gain value at the time of reading address information for each layer, the gain stored at the time of recording or reproduction can be used, so that it is not necessary to obtain the optimum gain again, and recording or reproduction can be performed. The time required for setting can be reduced, and the overall time can be reduced.

  According to the first aspect of the present invention, there is provided an objective lens for condensing laser light on an optical disk, a light receiving sensor for receiving reflected light from the optical disk and converting it into an electrical signal, an amplifier for amplifying the electrical signal, and amplified electrical If the S-shaped waveform is detected based on the signal, the number of layers of the optical disc is determined based on the number of detected S-shaped waveforms, the arbitrary address information of each layer is read, and the address information of one layer cannot be read, And a control means for increasing the gain of the amplifier until the address information can be read from one layer and storing the gain value when the address information is read for each layer.

  According to this configuration, when the number of layers of the optical disk is determined based on the number of S-shaped waveforms detected from the focus error signal, arbitrary address information of each layer is read, and when address information of a certain layer cannot be read, By increasing the gain of the amplifier until the address information can be read, the signal gain of the light receiving sensor can be optimized in a low-reflectance optical disk such as a phase change optical disk, so recording and reproduction are optimized for each recording layer of the optical disk. Thus, recording and reproduction quality can be improved.

  Also, by storing the gain value at the time of reading address information for each layer, the gain stored at the time of recording or reproduction can be used, so that it is not necessary to obtain the optimum gain again, and recording or reproduction can be performed. The time required for setting can be reduced, and the overall time can be reduced.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the discriminating number of layers and the information on the number of optical disc layers stored in the optical disc do not coincide with each other, the control means can set an arbitrary address of each layer. When the information was read and the address information of one layer could not be read, the gain of the amplifier was increased until the address information could be read from one layer, and the gain value when the address information was read was stored for each layer Is.

  According to this configuration, when the discriminated number of layers does not match the information of the number of layers of the optical disc stored in advance in the optical disc, when reading arbitrary address information of each layer and reading the address information of a certain layer The gain of the amplifier is increased until the address information can be read from a certain layer, and the gain value when the address information is read is stored for each layer, so that the number of discs determined by the S-shaped waveform and the discriminated information can be obtained. Even if the unique information of the optical disk recorded at a predetermined position on the optical disk is different, the condition for reading the address information can be obtained for each type of optical disk and for each number of layers. As a result, it is possible to optimize the gain setting of the amplifier of the light receiving sensor during recording and reproduction of an optical disk with a low reflectance.

  In addition, regarding an optical disc apparatus before the release of a newly developed optical disc, various settings required for recording / reproducing can be performed even on an optical disc that does not have information on the optical disc. Even when an optical disc with an increased number is released, the gain of the amplifier can be set optimally and recording or reproduction can be performed.

  In addition, since the gain of the amplifier set so that the address information can be read is stored in the storage means, the gain stored at the time of recording or reproduction can be used, so that it is not necessary to obtain the optimum gain again, and recording or reproduction is performed. The time required for the setting can be shortened, and the overall time can be shortened.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, there is provided storage means for storing the gain of the amplifier for each layer according to the number of layers of the optical disk. When the information on the number of layers of the optical disk stored in advance in the optical disk matches, the gain stored in the storage means is set in the amplifier.

  According to this configuration, when the discriminated number of layers matches the information on the number of layers of the optical disc stored in the optical disc in advance, the control means sets the gain of the amplifier stored in the apparatus for each layer. As a result, the stored gain can be used based on the unique information stored in advance on the optical disc, so that it is not necessary to obtain the optimum gain, the time required for recording or playback setting can be reduced, and the overall time is reduced. become able to.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the S-shaped waveform is a focus error signal obtained from an electric signal obtained by receiving and converting reflected light from an optical disk.

  According to this configuration, the S-shaped waveform is obtained by using the focus error signal obtained from the electric signal converted by receiving the reflected light from the optical disc, and thus the number of recording layers is obtained by the number of recording layers in focus. The number of recording layers can be easily obtained simply by moving the objective lens once from the position away from the optical disk to the optical disk surface. As a result, the time required to obtain the number of recording layers can be reduced, and the overall time can be reduced.

  According to the fifth aspect of the present invention, when information is recorded on or reproduced from the optical disc, the laser beam is focused on the optical disc, the reflected light from the optical disc is received and converted into an electrical signal, and the electrical signal is amplified. The S-shaped waveform was detected based on the amplified electrical signal, the number of layers of the optical disc was determined based on the number of S-shaped waveforms, arbitrary address information of each layer was read, and the address information of a certain layer could not be read In this case, the gain of the amplifier is increased until the address information can be read from a certain layer, and the gain value when the address information is read is stored for each layer.

  According to this method, the number of layers of the optical disk is determined based on the number of S-shaped waveforms, and when arbitrary address information of each layer is read and the address information of a certain layer cannot be read, the address information can be read from a certain layer. By increasing the gain of the amplifier, the signal gain of the light receiving sensor can be optimized in a low reflectivity optical disc such as a phase change type optical disc, so that the recording / reproducing conditions can be set for each recording layer of the optical disc.

  Also, by storing the gain value at the time of reading address information for each layer, the gain stored at the time of recording or reproduction can be used, so that it is not necessary to obtain the optimum gain again, and recording or reproduction can be performed. The time required for setting can be reduced, and the overall time can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view of an optical disc apparatus according to Embodiment 1 of the present invention, and FIG. 2 is an external view of the optical disc apparatus according to Embodiment 1 of the present invention, with the top of the housing removed.

  1 and 2, the optical disc apparatus 1 includes a housing 2 and a tray 3. FIGS. 1 and 2 show a state in which the tray 3 is pulled out from the housing 2.

  The housing 2 is composed of a top 2a and a bottom 2b. An optical pickup module 4 is provided on the tray 3. The optical pickup module 4 includes an optical pickup 5 constituting an optical system, a spindle motor 4a for rotating the optical disk, and a circuit board 4c constituting a control circuit.

  The optical pickup 5 provided in the optical pickup module 4 moves toward and away from the spindle motor 4a, that is, moves in the radial direction of the optical disk. The spindle motor 4a has an optical disk mounting portion 4b, and the optical disk mounting portion 4b rotates the mounted optical disk.

  Rails 6 are provided on both sides of the tray 3, and both sides are fitted to the rails 7 so as to be slidable in the direction of drawing out the optical disk. The rail 7 is also slidably fitted in the optical disk pull-out direction with rail guides 8 provided on the inner surfaces of both sides of the housing 2, and the tray 3 can be inserted into and removed from the housing 2. When the tray 3 is pulled out from the housing 2 by a predetermined length, the tray 3 is locked to the housing 2. At this time, the optical disk can be mounted on or removed from the optical disk mounting portion 4 b provided on the tray 3. The tray 3 is provided with an extruding portion 12, and the tray 3 pops out of the housing 2 when the extruding portion 12 pushes the housing 2 during a discharge (eject) operation.

  The optical disc apparatus 1 has a data transfer rate of 20 Mbps or higher, with an optical disc corresponding to a high-speed type such as CD-ROM, CD-R / RW, or DVD, and a high data transfer rate.

  A circuit board 9 having a control circuit is provided on the bottom 2b of the housing 2, and a circuit board 4c having a control circuit is provided on the tray 3. The circuit board 9 and the circuit board 4c are connected by a flexible printed circuit board (also referred to as an FPC) 10. The FPC 10 establishes electrical continuity between the circuit board 9 and the circuit board 4c.

  As a power system, power is supplied to a spindle motor 4a and a feed motor (not shown) provided in the optical pickup module 4 for driving the optical pickup 5 in the radial direction of the optical disk and a laser (see FIG. The signals include data signals that are read from or written to the optical disc, and signals that control the spindle motor 4a, the feed motor, and the laser.

  FIG. 3 is a block diagram of the optical disc apparatus according to Embodiment 1 of the present invention.

  In FIG. 3, 111 is a personal computer, 1 is an optical disk device, 15 is an interface cable, 20 is an interface, 11 is an optical disk, 4 is an optical pickup module, 5 is an optical pickup, 4a is a spindle motor, 205 is focus drive means, 31 Is an objective lens, 207 is a laser that is a laser emitting means, 208 is a light receiving sensor that is a reflected light receiving means, 209 is a carriage, 212 is a digital servo controller, 213 is a data processing unit, 214 is a focus control means, and 215 is a tracking control. Means 217, address reading means, 218, rotation control means, 219, spindle motor driving means, 220, storage means, 221, FE signal generation means, 222, focus error detection means, 223, gain setting means, 227, RF Is an issue generating means.

  The personal computer 111 and the optical disc apparatus 1 are connected by an interface cable 15, and data recorded on the optical disc 11 is output to the personal computer 111 via the interface 20, and data of the personal computer 111 is output to the optical disc 11.

  The optical disc apparatus 1 connected to the personal computer 111 via the interface 20 responds based on a control signal from the personal computer 111, for example, an ATAPI packet command, and reads information on the optical disc 11 or records information on the optical disc 11. The interface 20 is a SCSI interface, an IDE interface, or the like.

  The spindle motor 4a rotates the optical disc 11.

  The optical pickup module 4 which is an optical pickup means has a laser 207 and emits a laser beam to record and reproduce by irradiating the optical disk 11 when recording data on the optical disk 11 and reproducing information on the optical disk 11.

  The optical pick-up module 4 is provided with a carriage 209, and the optical pickup module 4 is moved toward and away from the spindle motor 4a by a feed motor (not shown) as a moving means of the optical pickup module 4, that is, the radius of the optical disk 11 Move in the direction.

  The laser beam output from the laser 207 is controlled by the focus control unit 214 so as to be focused on a predetermined focus position of the optical disc 11 and is focused by the focus driving unit 205.

  The reflected light of the laser light from the optical disk 11 is received by the light receiving sensor 208 which is a reflected light receiving means and converted into an electric signal. The converted electric signal of the reflected light is output by the focus error (FE) signal generating means 221. The FE signal is generated, and signal processing such as amplification of the received electric signal is performed by the RF signal generation means 227 that is an information signal.

  Information on the optical disk 11 is sent to the digital servo controller 212, and tracking control is performed by the tracking control means 215 and focus control is performed by the focus control means based on the tracking error signal and the focus error signal.

  The address reading unit 217 reads address information set in advance on the recording layer of the optical disc 11 based on an RF signal that is an information signal.

  Based on the focus error signal, the data processing unit 213 obtains the number of recording layers of the optical disc 11 based on the amplitude of the focus error signal and the number of S-shaped waveforms.

  FIG. 4 is a diagram showing a focus error signal according to the first embodiment of the present invention.

  FIG. 4 shows a focus error signal when the objective lens 31 is moved closer to the optical disc surface from a position away from the optical disc 11 by the focus driving means 205.

  FIG. 4C shows the time when the objective lens is brought closer and the focus (FC) drive value.

  In FIG. 4A, reference numerals 201 and 202 denote recording layers. When the optical disk 11 has one recording layer, the recording layer 201 indicated by a solid line is provided. When the optical disk 11 has two recording layers, a recording layer 202 indicated by a dotted line is provided at a position away from the recording layer 201. Further, when a plurality of recording layers are provided, the recording layer is further provided at a position away from the recording layer 202. In the first embodiment of the present invention, the optical disc 11 having up to two recording layers will be described. Since it is equivalent to a configuration having two recording layers, detailed description thereof is omitted.

  FIG. 4B shows a waveform of a focus error signal (FE) obtained for each type of the optical disk 11 based on the reflected light by irradiating the recording surface of the optical disk 11 with a predetermined gain. As shown in FIG. 4B, the focus error signal FE is detected as an S-shaped waveform before and after the laser light is focused on the recording layers 201 and 202 of the optical disc 11.

  When the optical disk 11 is a highly reflective medium such as a DVD-ROM or DVD-R having one recording layer, one S-shaped waveform is detected and its amplitude is W1. When the optical disk 11 is a phase change type medium such as a DVD-RW with a small reflectance, one S-shaped waveform is detected and its amplitude is W2, and the detected S-shaped waveform has an amplitude of W2 <W1.

  In the DVD-R DL in which the optical disc 11 has two recording layers and the reflectance is high, two S-shaped waveforms are detected corresponding to the first recording layer and the second recording layer, and the first layer is detected. With the recording layer amplitude W3 and the recording layer W4 corresponding to the second layer, the amplitude of the second layer becomes smaller and W3> W4.

  W3 is set substantially equal to W1 and W4 is set equal to W2.

  When the optical disc 11 has two recording layers and a low reflectance, the DVD-RW DL detects two S-shaped waveforms corresponding to the first recording layer and the second recording layer. With the recording layer amplitude W5 and the recording layer W6 corresponding to the second layer, the amplitude of the second layer becomes smaller and W5> W6.

  By setting the threshold level for obtaining the S-shaped detection signal based on the S-shaped signal of the FE signal to be smaller than W6, the number of recording layers of the optical disk can be determined by counting the S-shaped detection signal at the position where the FE signal exceeds the threshold. Ask.

  FIG. 5 is a diagram showing the relationship between wobbles and land pyribits on the disk substrate according to Embodiment 1 of the present invention. FIG. 5 illustrates a DVD-RW.

  As shown in FIG. 5A, the optical disc 11 includes a groove 501 that is a guide groove for laser light and a land 502, and the groove 501 has a wave (wobble) at a constant period to generate a signal that serves as a reference for the optical disc. I want to ask. Land pre-bits (LPP) are provided in the land 502 between the grooves, and address information is generated in advance. LPP is also used for phase control.

  As shown in FIG. 5B, the wobble signal 504 is obtained based on the undulation of the groove 501 and the LPP.

  When the light reception level of the reflected light from the optical disk 11 is reduced, the level of the RF signal that is an information signal based on the reflected light from the optical disk 11 is also reduced, and the address information detected based on the RF signal may not be read. In particular, as the optical disk 11 is a phase change type medium having a low reflectivity and becomes a higher layer of a plurality of layers, the address information may be misrecognized.

  Therefore, the address information is reliably read in a plurality of higher layers depending on the environmental conditions of recording and reproduction.

  Hereinafter, a procedure for reading the address information generated on the optical disc 11 during recording or reproduction will be described with reference to a flowchart.

  FIG. 6 is a flowchart of the recording or reproducing operation according to Embodiment 1 of the present invention.

  In FIG. 6, when the process is started (S501), it is determined whether or not the optical disk 11 is mounted on the optical disk apparatus 1 (S502). If the optical disk 11 is not mounted, it waits for the optical disk 11 to be mounted. . If it is determined that the optical disk 11 is loaded and the optical disk 11 is present, initialization is performed (S503). In this initial setting, the gain of the RF signal for the optical disk 11 is set to an initial setting value, or the rotation of the spindle motor 4a is rotated.

  When the initial setting is completed, a laser beam is irradiated to a predetermined position of the optical disc 11, and the reflected light from the optical disc 11 is received while the objective lens 31 is brought closer to the recording surface of the optical disc 11 from a position away from the optical disc 11. The reflected light signal is detected (S504), the number of S-shaped signals detected from the reflected light based on the focus error (FE) signal is obtained (S505), and the number of recording layers of the optical disk 11 is determined (S506). .

  Also, it is determined whether or not the optical disk 11 is of a low reflectance type from the reflected light (S507), and if the reflected light is of a low reflectance type such as a medium of a phase change type optical disk, a gain setting process is performed. (S508) After performing the gain setting process, it is determined whether or not a command related to recording or reproduction has been input from the personal computer 111 (S509), and if there is an input, it moves to a predetermined recording layer (S510), and the predetermined recording layer Is read from the storage means 220 (S511), a predetermined recording or reproduction operation is performed (S512), whether or not recording or reproduction is to be ended is determined (S513), and if it is determined to be completed, an end process is performed (S513). S514). When the process is continued without ending, the process returns to the command input process (S509) and the process is continued.

  If it is determined that the reflected light is not a low reflectance type (S507), the eigenvalue of the optical disc 11 set in the optical disc 11 is acquired (S515), and the gain value set based on the eigenvalue is set (S516). After performing the setting process, it is determined whether or not a command related to recording or reproduction has been input from the personal computer 111 (S517), and if there is an input, it moves to a predetermined recording layer (S518) and performs a predetermined recording or reproduction operation ( In step S519, it is determined whether to end recording or reproduction (step S520). When the process is continued without ending, the process returns to the command input process (S517) and the process is continued.

  FIG. 7 is a flowchart of the gain setting process according to the first embodiment of the present invention.

  When the gain setting process is started (S601), it moves to the first layer (S602), performs focus pull-in to focus on the moved predetermined layer (S603), turns on the focus servo (S604), and tracking servo Is turned on (S605), track address information is acquired (S606), it is determined whether the address information can be read (S607), and when the address information cannot be read, the gain setting of the RF signal amplifier is changed (S608). , (S606) and the processing is continued.

  When the address can be read (S607), the gain value of the amplifier of the RF signal at the time of reading is stored in the main storage stage (S609), and it is determined whether or not the gains of all the recording layers have been acquired (S610). The gain setting process is terminated (S611).

  If all gain settings have not been completed (S610), the tracking servo is turned off (S612), the focus servo is turned off (S613), the recording layer moves to the next recording layer (S614), and the process returns to (S603) to continue the processing. .

(Embodiment 2)
A second embodiment of the present invention will be described with reference to the drawings. In addition, about Embodiment 2 of this invention, it abbreviate | omits without repeating about the structure and procedure which overlap Embodiment 1 of this invention.

  On the inner periphery of the optical disk 11, there is an area having unique information of the optical disk 11. If the number of recording layers obtained based on the S-shaped waveform of the FE signal matches the number of recording layers obtained based on the unique information in this area, the RF corresponding to the number of recording layers obtained based on the unique information. It may be a gain value of the signal. In addition, it is not compatible with all types of optical disks, and is configured to be compatible with unset optical disks or newly released optical disks.

  FIG. 8 is a flowchart of the recording or reproducing operation according to the second embodiment of the present invention.

  In FIG. 8, when the process is started (S701), it is determined whether or not the optical disk 11 is mounted on the optical disk apparatus 1 (S702). If the optical disk 11 is not mounted, the process waits for the optical disk 11 to be mounted. . If it is determined that the optical disk 11 is loaded and the optical disk 11 is present, initialization is performed (S703). In this initial setting, the gain of the RF signal for the optical disk 11 is set to an initial setting value, or the rotation of the spindle motor 4a is rotated.

  When the initial setting is completed, a laser beam is irradiated to a predetermined position of the optical disc 11, and the reflected light from the optical disc 11 is received while the objective lens 31 is brought closer to the recording surface of the optical disc 11 from a position away from the optical disc 11. The reflected light signal is detected (S704), the number of S-shaped signals detected from the reflected light based on the focus error (FE) signal is obtained (S705), and the number of recording layers of the optical disk 11 is determined (S706). Then, the unique value of the optical disk 11 set in the optical disk 11 is acquired (S707).

  Whether or not the optical disk 11 is of a low reflectance type is discriminated from the reflected light (S708). If the reflected light is of a low reflectance type such as a medium of a phase change type optical disk, the discriminated number of layers and the optical disk 11 are determined. It is determined whether the number of recording layers based on the unique information is the same (S709). If not, a gain setting process is performed (S710). After the gain setting process is performed, recording or reproduction is performed from the personal computer 111. It is determined whether or not a command is input (S711). If there is an input, it moves to a predetermined recording layer (S712), and a gain value corresponding to the predetermined recording layer is read from the storage means 220 (S713). Alternatively, a reproduction operation is performed (S714), and it is determined whether recording or reproduction is to be ended (S715). 16). When the process is continued without ending, the process returns to the command input process (S711) and the process is continued.

  When it is determined that the reflected light is not a low reflectance type (S708), or when the number of recording layers based on the unique information of the optical disk 11 is determined to be the same (S709), commands related to recording and reproduction are sent from the personal computer 111. It is determined whether or not there is an input (S718). If there is an input, it moves to a predetermined recording layer (S719), performs a predetermined recording or reproducing operation (S720), and determines whether or not to end recording or reproducing (S721). If it is determined that the process is to be terminated, a termination process is performed (S716). When the process is continued without ending, the process returns to the command input process (S718) to continue the process.

  By doing so, the gain value of the RF signal does not need to be obtained again if the unique information of the optical disc 11 and the obtained number of recording layers are equal, so that the time can be reduced as a whole. If they are not equal, the gain value can be optimized by newly obtaining the gain value of the RF signal. Since the obtained gain value is recorded in the storage means, the gain value is next loaded when the same optical disk 11 is mounted. Can be used. As a result, it becomes possible to deal with optical disc media from various manufacturers.

  In an optical disc apparatus and its recording / reproducing method, when address information of a certain layer cannot be read, the gain of the amplifier is increased until the address information can be read from a certain layer. Since the signal gain of the light receiving sensor can be optimized, it is useful for an optical disk apparatus used as an external recording apparatus capable of recording multiple times, such as a personal computer.

1 is a perspective view of an optical disc apparatus according to Embodiment 1 of the present invention. 1 is an external view of an optical disc apparatus according to Embodiment 1 of the present invention. 1 is a block diagram of an optical disc apparatus according to Embodiment 1 of the present invention. The figure which showed the focus error signal concerning Embodiment 1 of this invention The figure which showed the relationship between the wobble on a disk substrate concerning Embodiment 1 of this invention, and a land pyribit. Flowchart of recording or reproducing operation according to Embodiment 1 of the present invention Flowchart of gain setting processing according to Embodiment 1 of the present invention Flowchart of recording or reproducing operation according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk apparatus 2 Case 3 Tray 4 Optical pick-up module 4a Spindle motor 4b Optical disk mounting part 5 Optical pick-up 9 Circuit board 10 FPC
DESCRIPTION OF SYMBOLS 11 Optical disk 31 Objective lens 111 Personal computer 205 Focus drive means 207 Laser 208 Light receiving sensor 209 Carriage 212 Digital servo controller 213 Data processing part 214 Focus control means 215 Tracking control means 217 Address reading means 218 Rotation control means 219 Spindle motor drive means 220 Storage Means 221 FE signal generation means 222 Focus error detection means 223 Gain setting means 227 RF signal generation means

Claims (5)

An objective lens for condensing laser light on an optical disc;
A light receiving sensor that receives reflected light from the optical disc and converts it into an electrical signal;
An amplifier for amplifying the electrical signal;
An S-shaped waveform is detected based on the amplified electrical signal, the number of layers of the optical disc is determined based on the detected number of S-shaped waveforms, arbitrary address information of each layer is read, and an address of one layer An optical disc apparatus comprising: control means for increasing the gain of the amplifier until the address information can be read from the one layer when the information cannot be read, and storing the gain value when the address information is read for each layer. The control means reads arbitrary address information of each layer and cannot read address information of one layer when the determined number of layers and the information of the number of layers of the optical disc stored in the optical disc in advance do not match. 2. The optical disc apparatus according to claim 1, wherein the gain of the amplifier is increased until the address information can be read from the one layer, and the gain value when the address information is read is stored for each layer. A storage means for storing the gain of the amplifier for each layer according to the number of layers of the optical disc is provided,
The control means sets the gain stored in the storage means in the amplifier when the determined number of layers matches the information of the number of layers of the optical disk stored in advance in the optical disk. The optical disc apparatus according to claim 1. 2. The optical disc apparatus according to claim 1, wherein the S-shaped waveform is a focus error signal obtained from an electric signal obtained by receiving and converting reflected light from the optical disc. When recording or reproducing information on an optical disc,
Condensing laser light on the optical disc, receiving reflected light from the optical disc and converting it into an electrical signal,
Amplifying the electrical signal and detecting an S-shaped waveform based on the amplified electrical signal;
Determining the number of layers of the optical disk based on the number of S-shaped waveforms;
Read any address information of each layer,
An optical disc apparatus characterized by increasing the gain of an amplifier until address information can be read from the certain layer when address information of a certain layer cannot be read, and storing the gain value when the address information is read for each layer Recording and playback method.

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