JP2005093013A - Optical disk drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk drive device in which appropriate discrimination of an optical disk is made without scratching the surface of the disk even when a variety of optical disks are discriminated by using focus search. <P>SOLUTION: Discrimination is made by focus search for a CD optical disk, a DVD optical disk, an optical disk having the AOD standards and an optical disk having the Blu-lay standards which are to be mounted on a driver. In this case, the focus search should be made for the optical disks in order from the optical system having a longer working distance that is the moveable distance of an objective lens with respect to a mounted disk, i.e., in the order of the DVD optical disk, the CD optical disk, the AOD standard optical disk, and the Blu-lay standard optical disk. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical disc drive apparatus that discriminates optical discs having different standards while reproducing or recording / reproducing those optical discs.

  Currently, CD-type optical discs such as CD, CD-ROM, CD-R, and CD-RW are used as optical discs, and DVDs, DVD-ROMs, DVD-Rs, DVD-RWs, and DVD-RAMs are used for recording and reproduction with a red laser. , DVD + R, DVD + RW, and other DVD optical discs. In recent years, Blu-ray standards using blue lasers and AOD (Advanced Optical Disc) standards have been proposed, and commercialization of optical disks and drive devices using these standards is being promoted.

  By the way, various types of optical discs have been standardized and commercialized in this way, but the common points of all optical discs are that the disc size is “12 cm” in diameter and the thickness is “1.2 mm”. It is.

  Therefore, as a recent technical trend, development of a drive device that provides compatible playback and compatible recording functions while discriminating various types of optical discs having the same diameter and thickness but different standards has been actively conducted. ing.

  Conventionally, as a drive device of this type, for example, a drive device called a combo drive, while discriminating between CD optical disks such as CD, CD-ROM, CD-R, CD-RW and the like, DVD, DVD-ROM, etc. Compatible playback and recording on a CD-type recordable optical disc are possible. In a drive device called a multi-drive, a CD-type optical disk such as CD, CD-ROM, CD-R, CD-RW, DVD, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, DVD + R, Both compatible playback and compatible recording are possible while discriminating DVD-based optical discs such as DVD + RW.

  Here, as an example of a data reading mechanism (pickup) of such an optical disk drive device, an outline will be described with reference to FIG. 17, taking a mechanism conventionally employed in, for example, a DVD optical disk drive device as an example.

  As shown in FIG. 17, this type of optical disk drive apparatus normally includes a pickup 50 constituting a disk data reading mechanism. The pickup 50 basically includes a semiconductor laser oscillator 51 that oscillates the laser beam LB, a mirror 52 that reflects the laser beam LB, and a lens 53 that focuses the laser beam LB on the recording layer r of the optical disc. And a beam splitter 54 for guiding the reflected light from the optical disk and mirror 52 to the photosensor 56. The auxiliary mechanism is further provided with a voice coil 57 that allows the lens 53 to be finely moved in the vertical and horizontal directions for focusing (focusing) and tracking (laser trajectory adjustment).

In this example, a red laser diode mainly having a wavelength of 635 to 660 nm is used for the semiconductor laser oscillator 51 used as a light source. More specifically, in the laser beam LB emitted from the laser oscillator 51, only a predetermined polarization component is reflected to the disk side by the beam splitter 54, and further, the laser beam LB reflected by the mirror 52 (more precisely, the laser beam LB). Predetermined polarization component) is narrowed down by the lens 53 and irradiated to the pit rows formed in the recording layer r of the disc. On the other hand, the laser beam LB reflected from the pit row of the recording layer r reaches the beam splitter 54 via the lens 53 and the mirror 52, where only the polarization component different from the reflected polarization component is transmitted and the photo beam is transmitted. The light enters the sensor 56. The photosensor 56 is a part that converts the incident laser beam LB into an electric signal. The converted electric signal is amplified and sent to an external circuit of the pickup 50, where a known demodulation process or the like is performed. The

  Here, the lens 53 includes a collimator lens and an objective lens (not shown). Among these, the collimator lens is a lens for shaping the incident laser beam LB and allowing parallel light to enter the objective lens. On the other hand, the objective lens is a lens for focusing the parallel light incident from the collimator lens on the recording layer r of the disk. Incidentally, this objective lens is required to have high performance in order to focus the beam to the diffraction limit, and the lens aperture ratio NA is also set to a high aperture ratio, for example, NA = 0.65.

  As shown in FIG. 17, the lens 53 is supported by an arm member 55, and the voice coil 57 is provided on both side surfaces of the arm member 55 in a manner facing the arm member 55. It has been. The voice coil 57 is configured by winding a copper wire or the like around a thin paper or aluminum tube (bobbin), and the magnetic circuit is driven by applying an electric signal to the tube so that the lens 53 is supported. It is an electromagnetic coil which makes the arm member 55 which can be moved finely up and down and right and left.

  When the pickup 50 is focused, the voice coil 57 moves the lens 53 together with the arm member 55 in the vertical direction to adjust the distance between the disk surface and the objective lens.

  Next, the outline of the relationship between the detection signal accompanying the focus search of the pickup 50 and the drive control of the lens 53 will be described with reference to FIG. 18 shows a drive signal FED (FIG. 18A) for moving the lens 53 up and down, an FE (focus error) signal (FIG. 18B) detected along with the focus search, and an RF signal (FIG. 18). 18 (c)) shows the transition as a timing chart.

  As shown in FIGS. 18A to 18C, for example, at the timing t1, when the lens 53 is moved downward from the original position and gradually moved upward, a certain timing near the focal point is obtained. At t2, strong reflected light of the laser beam LB is detected, and an S-shaped error signal appears as an FE signal together with the RF signal. The focus position (focusing position) of the lens 53 is recognized at the timing (t2) at which the FE signal crosses zero, and thereafter, after passing through the upper drive limit (timing t3) corresponding to the focus position, the timing is reached. At t4, the lens 53 is returned to the original position. Further, when such focus search, that is, detection of the FE signal or RF signal is performed earlier (before timing t2), as indicated by a broken line in FIG. 18A, before the timing t3, The lens 53 reaches the upper drive limit.

  Here, the outline of the focus search has been described by taking a DVD optical disk drive device as an example. However, when it becomes a drive device that records and reproduces disks of all formats including the above-mentioned Blu-ray standard and AOD standard, Techniques for discriminating optical disks with various specifications are important. As a method for discriminating these various optical discs, the above-described focus search is usually used. That is, the FE signal and the RF signal are detected as the disc is inserted, and disc discrimination is performed according to the level.

  However, in this case, as the optical system of the pickup, in addition to the current CD / DVD system, an optical system corresponding to the Blu-ray standard or the AOD standard is added. The drive control unit that performs this operation switches the optical system many times and repeats the focus search to perform disc discrimination. That is, when discs are discriminated, when a moving distance of the objective lens with respect to the disc, that is, a working optical disc having a long working distance, for example, a DVD type optical disc is mounted on the drive, the optical disc of the optical disc of the Blu-ray standard having a short working distance, for example. Focus search may be performed in the system. For this reason, in an extreme case, there is a possibility that the objective lens of the optical system corresponding to the Blu-ray standard may come into contact with the DVD optical disk and damage the disk surface.

  Incidentally, the working distance of each optical system varies depending on the type of the target optical disc, and is usually “0.9 mm” for the optical system of the optical disc stipulated by AOD, and “1.2 mm˜ 1.3 mm ”,“ 0.99 mm ”for the CD optical system, and“ 0.3 mm to 0.7 mm ”for the optical system of the Blu-ray standard optical disc.

  The present invention has been made in view of such circumstances, and an optical disc drive device capable of properly discriminating between optical discs without damaging the disc surface even when discriminating various optical discs by focus search. The purpose is to provide.

  In order to achieve such an object, the invention described in claim 1 is an optical disc drive apparatus that performs discriminating of optical discs by a focus search for optical discs composed of a plurality of standards to be attached to one drive. The gist of this is that the focus search is finally performed by an optical system having the shortest working distance, which is the movable distance of the objective lens with respect to the optical disc.

  According to such a configuration, the focus search by the optical system of the standard with the shortest working distance is performed last, so that the discrimination of the mounted optical disk is completed before the optical system of the standard with the shortest working distance is reached. Is more likely to do. Thereby, at the time of disc determination by focus search, inconveniences such as the objective lens coming into contact with the optical disc and scratching the disc surface are preferably avoided.

  According to a second aspect of the present invention, there is provided an optical system according to the first aspect, wherein the optical disc comprising the plurality of types of standards includes a Blu-ray standard optical disc, and the focus search is performed at the end. The gist is that the optical system is compatible with the Blu-ray standard optical disc.

  According to such a configuration, even when a Blu-ray standard optical disk is included as an optical disk composed of a plurality of types mounted on one drive, the focus search by the Blu-ray standard optical system with a short working distance is the last. By doing so, there is a high possibility that the determination of the mounted optical disk is completed before the focus search by the optical system is executed. For this reason, even in a multi-drive or the like corresponding to the Blu-ray standard optical disk, contact between the objective lens and the disk surface due to the focus search at the time of the disk determination is preferably avoided.

Further, the invention according to claim 3 is the optical disc drive apparatus according to claim 1, wherein the optical disc composed of the plurality of standards includes an optical disc of AOD standard, and the optical system for performing the focus search at the end includes: The gist is that the optical system is compatible with the optical disc of the AOD standard.

  According to such a configuration, even when an AOD standard optical disk is included as an optical disk composed of a plurality of types mounted on one drive, a focus search is performed last by an AOD standard optical system with a short working distance. Thus, there is a high possibility that the determination of the mounted optical disk is completed before the focus search by the optical system is executed. For this reason, even in a multi-drive or the like corresponding to the optical disc of the AOD standard, the contact between the objective lens and the disc surface due to the focus search at the disc discrimination is preferably avoided.

  Also, the invention according to claim 4 is the optical disc drive apparatus according to claim 1, wherein the optical disc composed of the plurality of types includes a Blu-ray standard optical disc and an AOD standard optical disc. The gist of the present invention is that the optical system for performing the focus search is an optical system compatible with the optical disc of the Blu-ray standard.

  According to such a configuration, even when both a Blu-ray standard optical disc and an AOD standard optical disc are included as a plurality of types of optical discs mounted on one drive, the Blu-ray standard with a shorter working distance is included. Since the focus search by the optical system is performed lastly, it is highly likely that the determination of the mounted optical disk including the AOD standard optical disk is completed before the focus search by the optical system is executed. . For this reason, even in a multi-drive compatible with both the Blu-ray standard optical disc and the AOD standard optical disc, the contact between the objective lens and the disc surface caused by the focus search at the disc discrimination is preferably avoided. Will come to be.

  According to a fifth aspect of the present invention, in the optical disk drive device according to any one of the first to fourth aspects, the focus search is performed in order from the optical system having a long working distance. The gist.

  According to such a configuration, with respect to optical systems of optical discs of all corresponding standards, the focus search by the optical system having a relatively short working distance is not executed before the focus search by the other optical system. The contact between the objective lens and the disk surface can be avoided more accurately.

  According to the present invention, when optical discs of a plurality of types mounted on one drive are discriminated by focus search, the optical system corresponding to each optical disc is caused by a difference in working distance. Inconveniences such as the objective lens coming into contact with the optical disk and scratching the disk surface are preferably avoided.

  Hereinafter, an optical disk drive device according to an embodiment of the present invention will be described in detail with reference to the drawings. The optical disk drive apparatus of this embodiment employs a multi-drive system that supports the above-mentioned CD-type and DVD-type optical disks, Blu-ray standard optical disks, and AOD standard optical disks. Discrimination of the actually mounted optical disk is performed by focus search using different optical systems corresponding to the optical disk.

  First, the configuration of the optical disc drive apparatus according to this embodiment will be described with reference to FIGS.

  In the optical disk drive apparatus shown in FIG. 1, a pickup 100 is a part that reads data recorded on, for example, an optical disk OD with laser light and converts it into an electrical signal. In addition, a plurality of laser optical systems 110 to 140 provided in correspondence with the plurality of types of optical discs, and a PDIC (light receiving element circuit) that converts received light data by the optical systems 110 to 140 into electric signals. ) 150 or the like. Each of the optical systems 110 to 140 basically has the structure illustrated in FIG. 17, and only the drive system for driving the lens of each optical system or its control system is shared. This drive system or its control system is based on a drive signal FED given from a driver circuit 600, which will be described later. For example, in the focus search, the lenses of the corresponding optical system are exemplified in FIG. Drive control is performed in the manner described above. Further, the pickup 100 performs switching of lasers used in the optical systems based on a laser switching signal LDD given from a laser driving circuit 700 which will be described later, and a gain switching signal GS given from the system computer 300. Based on the above, the amplification gain of the PDIC 150 is switched.

  FIG. 2 schematically shows the internal structure of such a pickup 100 more specifically, but the structure of the pickup 100 will be described in more detail with reference to FIG. As described above, the pickup 100 includes a CD optical disc optical system 110, a DVD optical disc optical system 120, an AOD standard optical disc 130, and a Blu-ray standard optical disc 140. Has four different optical systems.

  Among these, in the optical system 110 of the CD optical disk, a far-infrared laser diode having a wavelength of 785 nm is used for the semiconductor laser oscillator 111 used as a light source. The laser light emitted from the laser oscillator 111 is converted into parallel light by the collimator lens 112, and only a predetermined polarization component is transmitted by the beam splitter 114. Then, the transmitted polarized component is narrowed down by the objective lens 113 having a lens aperture ratio NA = 0.45, and is irradiated onto the disk recording layer R. On the other hand, the laser light reflected from the disk recording layer R reaches the beam splitter 114 via the objective lens 113, where only the polarized component different from the transmitted polarized component is reflected and incident on the PDIC 150. In the case of this optical system 110, the movable distance (working distance WD) of the objective lens with respect to the mounted optical disk is 0.99 mm, and the distance from the disk surface of the CD optical disk to the recording layer R is 1.2 mm. .

  In the optical system 120 of the DVD optical disk, a red laser diode having a wavelength of 660 nm is used for the semiconductor laser oscillator 121 used as a light source. The laser light emitted from the laser oscillator 121 is converted into parallel light by the collimator lens 122 and only a predetermined polarization component is transmitted by the beam splitter 124. Then, the transmitted polarized component is narrowed down by the objective lens 123 having a lens aperture ratio NA = 0.65, and is irradiated onto the disk recording layer R. On the other hand, the laser light reflected from the disk recording layer R reaches the beam splitter 124 via the objective lens 123, where only the polarization component different from the transmitted polarization component is reflected and incident on the PDIC 150. In the case of this optical system 120, the movable distance (working distance WD) of the objective lens with respect to the mounted optical disk is 1.2 mm to 1.3 mm, and the distance from the disk surface of the DVD optical disk to the recording layer R is 0. .6 mm.

In the optical system 130 of the AOD standard optical disc, a blue laser diode having a wavelength of 405 nm is used for the semiconductor laser oscillator 131 used as a light source. The laser light emitted from the laser oscillator 131 is converted into parallel light by the collimator lens 132 and only a predetermined polarization component is transmitted by the beam splitter 134. And
The transmitted polarization component is narrowed down by the objective lens 133 having a lens aperture ratio NA = 0.65, and is irradiated onto the disk recording layer R. On the other hand, the laser light reflected from the disk recording layer R reaches the beam splitter 134 via the objective lens 133, where only the polarized component different from the transmitted polarized component is reflected and incident on the PDIC 150. In the case of this optical system 130, the movable distance (working distance WD) of the objective lens with respect to the mounted optical disk is 0.9 mm, and the distance from the disk surface of the AOD optical disk to the recording layer R is 0.6 mm. .

  In the optical system 140 of the Blu-ray standard optical disc, a blue laser diode having a wavelength of 405 nm is used for the semiconductor laser oscillator 141 used as a light source. The laser light emitted from the laser oscillator 141 is converted into parallel light by the collimator lens 142, and only a predetermined polarization component is transmitted by the beam splitter 144. The transmitted polarization component is narrowed down by the objective lens 143 having a lens aperture ratio NA = 0.85, and is irradiated onto the disk recording layer R. On the other hand, the laser light reflected from the disk recording layer R reaches the beam splitter 144 via the objective lens 143, where only the polarized component different from the transmitted polarized component is reflected and incident on the PDIC 150. In the case of this optical system 140, the movable distance (working distance WD) of the objective lens with respect to the mounted optical disk is 0.3 mm to 0.7 mm, and the distance from the disk surface of the Blu-ray optical disk to the recording layer R Is 0.1 mm.

  The PDIC 150 includes separate light receiving elements corresponding to the respective optical systems. For example, the reflected light from the optical system 110 of the CD optical disk is incident on the light receiving element 115. The light receiving element 115 has a light receiving area (A, B, C, D) divided into four as shown in FIG. 2, and the incident reflected light is converted into an electric signal for each of the light receiving areas. The light reception signals A, B, C, and D are generated by conversion. Further, the reflected light from the optical system 120 of the DVD optical disk is incident on the light receiving element 125. The light receiving element 125 also has a light receiving region (A, B, C, D) that is also divided into four parts. For each of the light receiving regions, the incident reflected light is converted into an electric signal, and the light receiving signal A, B, C, and D are generated. Similarly, the reflected light from the optical system 130 of the AOD standard optical disc is incident on the light receiving element 135, and the reflected light from the optical system 140 of the Blu-ray standard optical disc is incident on the light receiving element 145. These light receiving elements 135 and 145 also have a light receiving region (A, B, C, D) divided into four, and for each of the light receiving regions, the incident reflected light is converted into an electric signal and the light receiving signal A, B, C, and D are generated.

  The light receiving signals A to D are amplified by the amplifier Amp separately in the PDIC 150. Here, a switch SW is provided in the feedback path of each amplifier Amp, and gain switching as the PDIC 150 is possible through on / off of the switch SW. In other words, this gain switching is performed based on the gain switching signal GS output from the system computer 300, and the switch SW is controlled to be in the “off” state so that the “normal” gain is controlled. Set to “High” gain. The amplification degree as the amplifier Amp has a relationship of “Normal gain <High gain”. For the sake of convenience, FIG. 2 shows the amplifier Amp only corresponding to the light reception signal A, but the amplifier Amp having the same configuration is provided for each of the other light reception signals B to D. Each set of the received light signals A to D thus amplified in the PDIC 150 is finally selected by the selector 151 and output as a sensing signal SS including the signals A, B, C, and D. The output sensing signal SS is input to the servo amplifier 200 shown in FIG.

  The servo amplifier 200 receives the sensing signal SS (A, B, C, D) output from the pickup 100 and generates the above-described RF signal, FE signal, and tracking error (TE) signal from the sensing signal SS (A, B, C, D). is there.

  FIG. 3 shows an example of the internal circuit of the servo amplifier 200. The configuration of the servo amplifier 200 will be described in more detail with reference to FIG. As described above, the servo amplifier 200 calculates the light reception signals A to D to the sensing signal SS input from the pickup 100 to generate an RF signal and an FE signal. Specifically, the light reception signals B and D and the light reception signals A and C are added by the adders 201 and 202, respectively. The outputs (“B + D” and “A + C”) of the adders 201 and 202 are further added on the one hand by the adder 203 to generate the RF signal “(A + B + C + D)”. The FE signal “(B + D) − (A + C)” is generated by subtraction. The RF signal thus generated is output to the system computer 300 and the encoder / decoder 400 as shown in FIG. 1, and the other FE signal is output to the system computer 300 as shown in FIG. Normally, the RF signal and the FE signal are adjusted in amplitude (gain) by voltage control from the system computer 300. However, in FIG. 3, the VCA (voltage control amplifier) is not shown for convenience.

  In the servo amplifier 200, the light reception signals A and B and the light reception signals C and D are added by an adder 205 and an adder 206, respectively. The outputs (“A + B” and “C + D”) of the adders 205 and 206 are subtracted by a subtracter to thereby obtain a tracking error (TE) signal (“(A + B) − (C + D) for adjusting the tracking of the optical disk. ) ”). The generated TE signal is also output to the system computer 300, and the system computer 300 executes well-known focus tracking control (laser trajectory adjustment) based on the TE signal. In this embodiment, as will be described later, the TE signal is used to discriminate between a DVD-type optical disc and an AOD-standard optical disc.

  Further, the system computer 300 shown in FIG. 1 includes various control programs stored in a built-in memory and the like, and instructions transmitted via an interface 500 from an external processor unit (personal computer, player, recorder, etc.) not shown. This is a part for comprehensively controlling various functions as the optical disk drive device based on the above. The driver circuit 600 and the laser driving circuit 700 described below also execute necessary processes based on commands from the system computer 300, respectively. Specifically, the system computer 300 outputs the focus actuator drive signal OUS to the driver circuit 600, thereby executing control for selecting the optical system of the pickup 100. Further, by outputting a laser selection signal LDS to the laser driving circuit 700, control for selecting a laser oscillator to be used (driven) in the pickup 100 is executed. The above-described gain switching signal GS is also given from the system computer 300. On the other hand, the system computer 300 executes the focus tracking control and the focus search (focusing) based on the input RF signal and FE signal when recording and reproducing the optical disc. In the focus search, the amplitude information of the FE signal and the RF signal is set in the register, and the information is referred to as needed at the time of disc discrimination described later.

  Similarly, the encoder / decoder 400 shown in FIG. 1 is a part that performs encoding (modulation) processing and decoding (demodulation) processing in cooperation with the system computer 300.

For example, when recording (writing) data on an optical disc, the data transferred from the external processor unit via the interface (I / F) 500 is in accordance with the specification of the optical disc to be given from the system computer 300. Execute the encoding process. At the same time, a laser power and a signal LDP for controlling on / off of the laser are sent to the laser driving circuit 700 to control the corresponding optical system of the pickup 100, and the encoded data is transferred to the corresponding optical disk. Write to the recording layer.

  On the other hand, when reproducing data from the optical disk, a decoding process is performed in accordance with the specifications of the optical disk to be given from the system computer 300 based on the RF signal input from the servo amplifier 200. Then, the decoded data is transferred to the external processor unit via the interface (I / F) 500. As the interface (I / F) 500, for example, a circuit corresponding to a standard such as ATAPI (AT Attachment Packet Interface) or SCSI (Small Computer System Interface) can be appropriately employed.

  The driver circuit 600 shown in FIG. 1 generates the drive signal FED based on a signal OUS for optical system selection and control given from the system computer 300, and this is given to the pickup 100, This is a part that controls the selection and driving of the optical system in the pickup 100. Also in the focus search at the time of disc discrimination, which will be described later, lens driving of each selected optical system is performed via the driver circuit 600.

  The laser driving circuit 700 shown in FIG. 1 selects the laser oscillator in the pickup 100 based on the signal LDS given from the system computer 300, and based on the signal LDP given from the encoder / decoder 400, This is the part that controls the laser power and laser on / off of the selected laser oscillator. A control signal for this purpose is sent to the pickup 100 as the signal LDD.

  Next, a disc discrimination method using the focus search by the optical disc drive apparatus according to this embodiment will be described in detail with reference to FIGS.

  In this embodiment, the system computer 300 (FIG. 1) performs a focus search in order from the optical system with a long working distance WD, as shown in FIG. Disc discriminates the mounted optical disc.

  First, the outline of the disc discrimination method according to this embodiment will be described with reference to FIG.

  When discriminating the disc, first, as a first stage which is the processing of step S1, whether the mounted optical disc is a DVD disc, or if it is a DVD disc, in what format disc Is determined. That is, in this step S1, the optical system 120 (FIG. 2) of the DVD optical disk is selected based on the control of the system computer 300 (FIG. 1). If the mounted optical disc is a DVD disc and the format of the DVD disc can be determined, for example, “0” is substituted into the variable i. If the optical system 120 cannot discriminate the mounted optical disk, for example, “2” is substituted for the variable i. If the same optical disc can be discriminated as an AOD disc, for example, “3” is substituted for variable i.

  Then, in the conditional branch of step S2, it is determined whether or not the variable i is “0”, that is, whether or not the loaded optical disk is a DVD disk and a DVD disk format. As a result, if “YES (i = 0)” is determined, the determination processing is terminated (end), assuming that the loaded optical disk and the disk format are determined.

  On the other hand, if “NO” is determined in step S2, whether or not the variable i is “2” in the conditional branch in step S3, that is, the CD type disc having the next long working distance WD. It is determined whether or not discrimination should be started. If “YES (i = 2)” is determined in this step S3, it is determined whether or not the mounted optical disk is a CD disk as the second stage which is the process of step S4. I do. On the other hand, if “NO” is determined, it is determined whether or not the mounted optical disk is an AOD standard disk as the third stage in step S6.

  Here, first, in the second stage of step S4, the optical system 110 (FIG. 2) of the CD optical disk is selected. If the mounted optical disk is a CD disk and the format of the CD disk can be discriminated, for example, “0” is substituted for the variable i as described above. In the optical system 110, if the mounted optical disk is not discriminated, for example, “3” is substituted for the variable i.

  Then, in the conditional branch of step S5, it is determined whether or not the variable i is “0”, that is, whether or not the loaded optical disk is a CD disk and is a CD disk format. As a result, if “YES (i = 0)” is determined, the determination processing is terminated (end), assuming that the loaded optical disk and the disk format are determined. If “NO” is determined in the step S5, the process proceeds to the third stage of the step S6, that is, the AOD determination.

  In the third stage of step S6, the optical system 130 (FIG. 2) of the AOD optical disk is selected. If the mounted optical disc is an AOD standard disc and the disc format of the AOD standard can be discriminated, for example, “0” is substituted into the variable i. If the optical system 130 cannot discriminate the mounted optical disk, for example, “4” is substituted for the variable i.

  In the conditional branch of step S7, it is determined whether or not the variable i is “0”, that is, whether or not the loaded optical disc is an AOD standard optical disc and an AOD standard disc format. As a result, if “YES (i = 0)” is determined, the determination processing is terminated (end), assuming that the loaded optical disk and the disk format are determined. If “NO” is determined in the step S7, the process proceeds to the fourth stage of the step S8, that is, the Blu-ray determination.

  In the fourth stage of step S8, the optical system 140 (FIG. 2) of the Blu-ray standard optical disc is selected. Here, a determination is made as to whether the loaded optical disc is a Blu-ray standard disc or “NO DISC”.

  Hereinafter, with reference to FIGS. 5 to 13, the details of the processing in the first to fourth stages executed as a subroutine will be further described.

  First, with regard to the processing in the first stage, that is, disc discrimination using the DVD optical system 120 (FIG. 2) having the longest working distance WD (1.2 mm to 1.3 mm), FIG. 5, FIG. 9, FIG. Will be described in detail with reference to FIG. In this embodiment, “DVD-ROM double-layer disc”, “DVD-ROM single-layer / DVD-R recorded / DVD + R recorded disc”, “DVD-R unrecorded / DVD + R unrecorded disc” are used as DVD-based discs. ”,“ DVD-RW recorded / DVD + RW recorded disc ”, and“ DVD-RW unrecorded / DVD + RW unrecorded disc ”.

  As shown in FIG. 5, the disc discrimination of the DVD system is started with the gain as the PDIC 150 (FIG. 2) set to “Normal” by the gain switching signal GS (step S101). Here, the optical system 120 (FIG. 2) of the DVD optical disk is selected as described above, so that the wavelength of the semiconductor laser oscillator is set to 660 nm and the numerical aperture NA of the objective lens is set to 0.65 (step S102). In this state, the focus search in the manner illustrated in FIG. 18 is executed (step S103).

  Next, in step S104, it is determined whether or not the FE signal detected in association with the focus search is an FE signal for a two-layer disc. As shown in FIG. 9, the FE signal of the double-layer disc has two consecutive S-shaped waveforms as the objective lens is brought closer to the disc. Of these, the first is the S-shaped waveform of the first layer, and the second is the S-shaped waveform of the second layer. FIG. 9 is a schematic waveform of the FE signal (FE2) of the double-layer disc when the DVD optical disc optical system 120 is used. In addition, the FE signal (FE2) of such a double-layer disc can be an AOD standard regardless of whether it is an optical disc having a two-layer structure, as long as an optical system corresponding to the mounted optical disc is selected. Whether the optical disc is the same or a Blu-ray standard optical disc, both are detected as substantially similar waveforms. Therefore, in this case, by detecting the FE signal of the double-layer disc (determined as “YES” in step S104), it is possible to determine that the mounted optical disc is a DVD-ROM double-layer disc. In this case, “0” is substituted for the variable i (step S105), and the first stage processing is terminated. That is, the process returns to the main routine of FIG.

  On the other hand, if “NO” is determined in step S104, whether or not the amplitude value of the FE signal detected in association with the focus search exceeds a threshold value T registered in advance in the system computer 300 (FIG. 1). Is determined (step S106). FIG. 10 shows an example in which FE signals of various optical disks are detected by the optical system 120 (FIG. 2) of the DVD optical disk. As shown in FIG. 10, when a focus search of a DVD-type disc is performed by the optical system 120 of the DVD-type optical disc, an FE signal having the maximum amplitude is obtained. Here, if the maximum amplitude value is “1”, and the threshold T is a value corresponding to “0.75”, for example, two optical discs exceeding the threshold T are DVD-type discs and AOD standard discs. Only type. When the gain of the PDIC 150 (FIG. 2) is “Normal” as described above, the reflectivity of the phase change recording DVD ± RW is about 15 to 30% (DVD -ROM is about 70%, DVD ± R is about 70%), and the threshold value T is not exceeded.

  If “YES” is determined in the step S106, the discrimination between the DVD optical disk exceeding the threshold T and the optical disk of the AOD standard is made with focus on, and the difference between the pit length and the track pitch (RF signal, TE) This is performed by examining (appears in the (tracking error) signal) (step S107). Incidentally, the relationship between “DVD pit length> AOD pit length” and “DVD track pitch> AOD track pitch” is established between these DVD optical discs and AOD standard optical discs.

If it is determined in this step S107 that the DVD is a DVD ("YES"), it is then determined in step S108 whether or not RF signals are continuously detected from the disc. That is, when the “RF signal = A + B + C + D” changes repeatedly during data reading with focus on, recording data exists. If recorded data exists (“YES” in step S108), the optical disc is any one of “DVD-ROM single layer disc”, “DVD-R recorded disc”, and “DVD + R recorded disc”. Is determined. In this case, “0” is substituted for the variable i (step S109), and the processing in the first stage is completed. If “NO” is determined in the step S108, it is determined that the disc is “DVD-R or DVD + R unrecorded disc”. In this case as well, the above “0” is substituted for the variable i (step S110), and the processing in the first stage is terminated.

  On the other hand, if “NO” is determined in step S107, it is determined that the optical disc is an AOD standard optical disc. The above “3” is substituted for the variable i (S111), and the processing in the first stage is finished.

  On the other hand, if “NO” is determined in step S106, the focus search is executed again (step S113) after switching the gain of the PDIC 150 (FIG. 2) to “High” (step S112). . Incidentally, by setting the gain of the PDIC 150 to “High”, even if the mounted optical disk is a DVD ± RW of the phase change recording method having a low reflectance, the optical system of the DVD optical disk is used as an optical system. As long as the system 120 is used, the FE signal illustrated in FIG. Therefore, the FE signal obtained by this focus search is again compared with the threshold value T to determine whether or not the FE signal exceeds the threshold value T (step S114). If the threshold value T is exceeded (“YES”), it is determined whether or not the RF signal changes repeatedly (step S115). If the RF signal changes repeatedly, that is, if recording data exists (“YES”), it is determined whether or not there is lead-in information (step S116). Here, the lead-in information is information written at the beginning of the session inside the disc. The lead-in area includes an R / RW wobble (meander), disc type, laser power, and disc manufacture. The manufacturer and usage area are written. Therefore, by reading this lead-in information, it is determined whether or not the information is present. If there is lead-in information (“YES”), the disc is “DVD-RW recorded disc”, DVD + RW recorded. That it is one of the used disks. In this case as well, the above “0” is substituted for the variable i (step S117), and the processing in the first stage is terminated. If it is determined in step S116 that there is no lead-in information, “2” is substituted for variable i (step S118), and the process in the first stage is terminated.

  If it is determined in step S115 that there is no RF signal, that is, there is no repetition of the intensity signal (“NO”), it is also determined whether there is lead-in information (step S119). If there is lead-in information (if “YES” is determined), it is determined that the optical disc is “DVD-RW unrecorded disc” or “DVD + RW unrecorded disc”. Also in this case, the above “0” is substituted for the variable i (step S120), and the processing in the first stage is completed. If it is determined in step S119 that there is no lead-in information, “2” is substituted for variable i (step S121), and the processing in the first stage is terminated.

  Next, referring to FIG. 6 and FIG. 11, the second stage process, that is, disc discrimination using the CD system optical system 110 (FIG. 2) having the second longest working distance WD (0.99 mm). This will be described in detail. In the present embodiment, “CD / CD-ROM / CD-R recorded disc”, “CD-R unrecorded disc”, “CD-RW recorded disc”, “CD-” are used as CD-type discs. Each “RW unrecorded disc” is determined.

As shown in FIG. 6, CD disc discrimination is started with the gain as the PDIC 150 (FIG. 2) set to “Normal” by the gain switching signal GS (step S401). Here, the optical system 110 (FIG. 2) of the CD optical disk is selected as described above, so that the wavelength of the semiconductor laser oscillator is set to 785 nm and the aperture ratio NA of the objective lens is set to 0.45 (step). In this state, the focus search in the manner illustrated in FIG. 18 is executed (step S403).

  Next, in step S404, it is determined whether or not the amplitude value of the FE signal detected with the focus search exceeds a threshold value T registered in advance in the system computer 300 (FIG. 1) (step S404). .

  FIG. 11 shows an example in which FE signals of various optical disks are detected by the optical system 110 (FIG. 2) of the CD optical disk. As shown in FIG. 11, when a CD-system disc focus search is performed by the CD-system optical disc optical system 110, an FE signal having the maximum amplitude is obtained. Here, when the maximum amplitude value is “1”, if the threshold value T is set to a value corresponding to, for example, “0.75”, the optical disk exceeding this threshold value is only a CD type disk. When the gain of the PDIC 150 (FIG. 2) is “Normal” as described above, the CD ± RW of the phase change recording method has a low reflectance and exceeds the threshold value T even for the same CD type disc. There is nothing.

  If “YES” is determined in the step S404, it is then determined in a step S405 whether or not the RF signal is continuously detected from the disc. That is, when the “RF signal = A + B + C + D” changes repeatedly during data reading with focus on, recording data exists. If recorded data exists (“YES” in step S405), whether the optical disc is a “CD disc”, a “CD-ROM disc”, or a “CD-R recorded disc”. Is determined. In this case, “0” is substituted for the variable i (step S406), and the processing in the second stage is terminated. If “NO” is determined in the step S406, it is determined that the disc is “CD-R unrecorded disc”. In this case as well, the above “0” is substituted for the variable i (step S407), and the processing in the second stage is terminated.

  On the other hand, if “NO” is determined in step S106, the gain of the PDIC 150 (FIG. 2) is switched to “High” (step S408), and then the focus search is executed again (step S409). By the way, by setting the gain of the PDIC 150 to “High”, even if the mounted optical disc is the CD-RW of the phase change recording method with low reflectivity, the optical system of the CD optical disc is used as an optical system. As long as the system 110 is used, the FE signal illustrated in FIG. Therefore, the FE signal obtained by the focus search is again compared with the threshold value T to determine whether or not the FE signal exceeds the threshold value T (step S410). If the RF signal changes repeatedly, that is, if recording data exists (“YES”), it is determined whether or not there is lead-in information (step S412). Here, the lead-in information is information written at the beginning of the session inside the disc. The lead-in area includes an R / RW wobble (meander), disc type, laser power, and disc manufacture. The manufacturer, usage area, etc. are written. Therefore, by reading this lead-in information, it is determined whether or not the information is present. If there is lead-in information (“YES”), the disc is “CD-RW recorded disc”. Is determined. Also in this case, the above-mentioned “0” is substituted for the variable i (step S413), and the second stage is terminated. If it is determined in step S412 that there is no lead-in information, “3” is substituted for variable i (step S414), and the processing in the second stage is terminated.

In addition, when it is determined in step S411 that there is no RF signal, that is, there is no repetition of the intensity signal (“NO”), it is determined whether there is lead-in information (step S415). If there is information (if it is determined “YES”), it is determined that the optical disc is a “CD-RW unrecorded disc”. In this case as well, the above “0” is substituted for the variable i (step S416), and the processing in the second stage is terminated. If it is determined in step S415 that there is no lead-in information, “3” is substituted for variable i (step S417), and the processing in the second step is terminated.

  Next, FIG. 7, FIG. 9, FIG. 9, FIG. 9, FIG. 9, FIG. 9, FIG. 9, FIG. 9, FIG. This will be described in detail with reference to FIG. In this embodiment, “AOD-ROM dual-layer disc”, “AOD-ROM single-layer / AOD-R recorded disc”, “AOD-R non-recorded disc”, “AOD (rewritable type) are used as AOD standard discs. ) “Recorded disc” and “AOD (rewritable) unrecorded disc”.

  As shown in FIG. 7, AOD standard disc discrimination is started with the gain as the PDIC 150 (FIG. 2) set to “Normal” by the gain switching signal GS (step S601). Here, as described above, the optical system 130 (FIG. 2) of the AOD standard optical disc is selected, so that the wavelength of the semiconductor laser oscillator is set to 405 nm and the numerical aperture NA of the objective lens is set to 0.65 (step). S602), in this state, the focus search in the manner illustrated in FIG. 18 is executed (step S603).

  Next, in step S604, it is determined whether or not the FE signal detected in association with the focus search is an FE signal for a two-layer disc. As described above, when the objective lens is moved closer to the disc, the FE signal of the double-layer disc has two consecutive S-shaped waveforms as shown in FIG. Of these, the first is the S-shaped waveform of the first layer, and the second is the S-shaped waveform of the second layer. Therefore, in this case, it can be determined that the disc is an AOD-ROM dual-layer disc by detecting the FE signal of the dual-layer disc (by determining “YES” in step S604). In this case, “0” is substituted into the variable i (step S605), and the third stage processing is terminated. That is, the process returns to the main routine of FIG.

  On the other hand, if “NO” is determined in step S604, whether or not the amplitude value of the FE signal detected in association with the focus search exceeds a threshold value T registered in advance in the system computer 300 (FIG. 1). Is determined (step S606). FIG. 12 shows an example in which FE signals of various optical discs are detected by the optical system 130 (FIG. 2) of the AOD standard optical disc. As shown in FIG. 12, when an AOD standard disc focus search is performed by the optical system 130 of the AOD standard optical disc, an FE signal having the maximum amplitude is obtained. Here, if the maximum amplitude value is “1”, and the threshold T is a value corresponding to “0.75”, for example, two optical discs exceeding the threshold T are DVD-type discs and AOD standard discs. Only type. However, since disc discrimination (first stage) of the DVD disc has already been completed in the third stage, the FE signal of the DVD disc is not detected. When the gain of the PDIC 150 (FIG. 2) is “Normal” as described above, even in the same AOD standard disc, the phase change recording type AOD (rewritable type) has a low reflectance, and the above threshold value. Never exceed T.

If “YES” is determined in the step S606, it is then determined in a step S607 whether or not the RF signal is continuously detected from the disk. That is, when the “RF signal = A + B + C + D” changes repeatedly during data reading with focus on, recording data exists. If recording data exists (“YES” in step S607), it is determined whether the optical disc is an “AOD-ROM single layer disc” or an “AOD-R recorded disc”. . In this case, “0” is substituted for the variable i (step S608), and the process in the third stage is terminated. If “NO” is determined in the step S607, it is determined that the disc is “AOD-R unrecorded disc”. In this case as well, the above “0” is substituted for the variable i (step S609), and the processing in the third stage is finished.

  On the other hand, if “NO” is determined in step S606, the focus search is executed again (step S611) after the gain of the PDIC 150 (FIG. 2) is switched to “High” (step S610). . By the way, by setting the gain of the PDIC 150 to “High”, even if the mounted optical disc is an AOD (rewritable type) of the phase change recording method having a low reflectance, the optical system conforms to the AOD standard. As long as the optical system 130 of the optical disk is used, the FE signal illustrated in FIG. Therefore, the FE signal obtained by this focus search is compared with the threshold value T again to determine whether or not the FE signal exceeds the threshold value T (step S612). If the threshold value T is exceeded (“YES”), it is determined whether or not the RF signal changes repeatedly (step S613). If the RF signal changes repeatedly, that is, if recording data exists (“YES”), it is determined whether or not there is lead-in information (step S614). Here, the lead-in information is information written at the head of the session inside the disc, and the lead-in area includes an R / rewritable wobble (meander), disc type, laser power, disc The manufacturer and usage area are written. Therefore, by reading the lead-in information, it is determined whether or not the information is present. If the lead-in information is present (“YES”), the disc is “AOD (rewritable) recorded disc”. Determine that there is. In this case as well, the above “0” is substituted for the variable i (step S615), and the processing in the third stage is terminated. If it is determined in step S614 that there is no lead-in information, “4” is substituted for variable i (step S616), and the processing in the third stage is terminated.

  If it is determined in step S613 that there is no RF signal, that is, there is no repetition of the intensity signal (“NO”), it is determined whether there is lead-in information (step S617). If there is information (if “YES” is determined), it is determined that the optical disc is an “AOD (rewritable) unrecorded disc”. Also in this case, the above “0” is substituted for the variable i (step S618), and the processing in the third stage is finished. If it is determined in step S617 that there is no lead-in information, “4” is substituted for variable i (step S619), and the process in the third stage is terminated.

  Next, with regard to the processing in the fourth stage, that is, the disc discrimination using the optical system 140 (FIG. 2) of the Blu-ray standard optical disc with the shortest working distance WD (0.3 mm to 0.7 mm), FIG. This will be described in detail with reference to FIGS. In the present embodiment, “Blu-ray-ROM / Blu-ray-R recorded disc”, “Blu-ray-R unrecorded disc”, “Blu-ray double-layer disc” are used as Blu-ray standard discs. "," Blu-ray single-layer disc "," NO DISC "respectively.

  As shown in FIG. 8, the disc determination of the Blu-ray standard is started with the gain as the PDIC 150 (FIG. 2) set to “Normal” by the gain switching signal GS (step S801). Here, as described above, the optical system 140 (FIG. 2) of the Blu-ray standard optical disc is selected, so that the wavelength of the semiconductor laser oscillator is set to 405 nm and the aperture ratio NA of the objective lens is set to 0.85. (Step S802) In this state, the focus search in the manner illustrated in FIG. 18 is executed (Step S803).

Next, in step S804, it is determined whether or not the amplitude value of the FE signal detected with the focus search exceeds a threshold value T registered in advance in the system computer 300 (FIG. 1) (step S804). . FIG. 13 shows an example in which FE signals of various optical disks are detected by the optical system 140 (FIG. 2) of the Blu-ray standard optical disk. As shown in FIG. 13, when a focus search of a Blu-ray standard optical disc is performed by the optical system 130 of the Blu-ray standard optical disc, an FE signal with the maximum amplitude is obtained. Here, when the maximum amplitude value is “1”, if the threshold value T is set to a value corresponding to “0.75”, for example, the only optical disk exceeding the threshold value T is a Blu-ray standard disk. When the gain of the PDIC 150 (FIG. 2) is “Normal” as described above, even if the disc is the same Blu-ray standard, the Blu-ray double-layer disc has a low reflectance, and the threshold T is Never exceed.

  If “YES” is determined in the step S804, it is then determined in a step S805 whether or not the RF signal is continuously detected from the disc. That is, when the “RF signal = A + B + C + D” changes repeatedly during data reading with focus on, recording data exists. If recorded data is present (“YES” in step S805), whether the optical disc is a “Blu-ray-ROM disc” or a “Blu-ray-R recorded disc”. It is determined (step S806), and the process in the fourth stage is finished. If “NO” is determined in the step S805, it is determined that the optical disc is a “Blu-ray-R unrecorded disc” (step S609), and the processing in the fourth stage is ended. .

  On the other hand, if “NO” is determined in step S804, the focus search is performed again (step S809) after the gain of the PDIC 150 (FIG. 2) is switched to “High” (step S808). . By the way, by setting the gain of the PDIC 150 to “High”, even if the mounted optical disc is the Blu-ray double-layer disc with low reflectivity, the optical system of the Blu-ray standard optical disc as an optical system is used. As long as the system 140 is used, the waveform of the Blu-ray double-layer disc illustrated in FIG. 9 can be detected. Therefore, in this case, when the FE signal of the dual-layer disc is detected (determined as “YES” in step S810), the disc is discriminated as a Blu-ray dual-layer disc (step S105), and the processing of the fourth stage is performed. finish.

  On the other hand, if “NO” is determined in step S810, the FE signal obtained by this focus search is again compared with the threshold value T to determine whether or not the FE signal exceeds the threshold value T ( Step S812). If the threshold value T is exceeded (“YES”), it is determined that the optical disc is a “Blu-ray 1-layer disc” (step S813), and the processing in the fourth stage is terminated.

  On the other hand, if “NO” is determined in the step S812, it is determined that the optical disc is “NO DISC” (step S814), and the process in the fourth stage is ended.

  The disc discrimination and disc format are discriminated by the above procedure.

  According to the optical disc drive apparatus according to this embodiment that performs disc discrimination in the above-described manner, the excellent effects listed below can be obtained.

  (1) The disc is discriminated by performing a focus search in order from an optical system with a long working distance WD. For this reason, the focus search by the optical system having a relatively short working distance is not executed prior to the focus search by other optical systems, and the contact between the objective lens and the disk surface is accurately determined. Will be able to avoid.

  (2) Also, since disc discrimination is performed by sequentially switching optical systems one by one in accordance with the above procedure, it is possible to eliminate complications such as reusing an optical system that has been used once.

  (3) Even if both a Blu-ray standard optical disc and an AOD standard optical disc are included as optical discs of a plurality of types mounted on one drive, the optical system of the Blu-ray standard with a shorter working distance is used. The focus search was performed last. For this reason, before the focus search by the Blu-ray standard optical system is executed, there is a high possibility that the determination of the mounted optical disk including the AOD standard optical disk is completed. As a result, even in a multi-drive or the like compatible with both the Blu-ray standard optical disc and the AOD standard optical disc, the contact between the objective lens and the disc surface due to the focus search at the disc discrimination is suitable. It will be avoided.

  (4) Further, by adopting a discriminating algorithm for a single-sided dual-layer disc, disc discrimination with higher versatility such as Blu-ray standard and AOD standard optical discs as well as DVD-ROM dual-layer discs can be performed.

  Note that the optical disk drive device according to the present invention is not limited to the above-described embodiment, and can be implemented as, for example, the following forms obtained by appropriately changing the embodiment.

  In the above-described embodiment, the TE (tracking error) signal is generated by the so-called push-pull method. However, as a TE signal generation method, a three-beam method using two sub beams in addition to the main beam is also available. Also, a phase difference detection method for detecting the phase difference of the received light signal can be employed as appropriate.

  In the above-described embodiment, as the pickup 100, the optical system 110 for the CD optical disk, the optical system 120 for the DVD optical disk, the optical system 130 for the AOD standard optical disk, and the optical system 140 for the Blu-ray standard optical disk are separately provided. Although provided, it is not limited to such a configuration. For example, a single objective lens 3 laser structure, a dual objective lens 3 laser structure, and a DVD / CD and AOD / Blu-ray 2 pickup may be used as appropriate without necessarily including these four optical systems. That is, the physical structure as the pickup 100 is arbitrary.

  Here, as the one-objective-lens 3-laser structure, for example, by shifting the emission positions of semiconductor lasers having different wavelengths (for example, 785 nm, 660 nm, and 405 nm) with respect to one objective lens, the focus is achieved with one objective lens. There is a tying structure. Further, based on the same concept, the above-described two objective lens 3 laser structure can be adopted. Moreover, it is good also as a structure which focuses by changing not only the light emission position of a semiconductor laser but a lens position.

On the other hand, as an example of the two pickup structure, there is a structure illustrated in FIG. 14, for example. Here, for convenience, the DVD / CD bifocal pickup will be described. As described above, as shown in FIGS. 14A and 14B, the CD optical disc and the DVD optical disc have a thickness from the disc surface to the reflective layer (recording layer) R of “1”. .2mm "and DVD-type optical discs are greatly different from" 0.6mm ". For this reason, when the optical path is designed to focus on the DVD optical disk OD having a thickness of “0.6 mm” from the disk surface to the reflective layer R by the objective lens 123, the thickness is “1.2 mm”. In the CD optical disk OD, the objective lens 113 is not focused, and a good beam spot shape cannot be obtained on the reflective layer R. Therefore, for example, as illustrated in FIG. 14C, a hologram method is adopted in which a hologram H is formed on the objective lens L to form a bifocal beam for CD and DVD. In a bifocal pickup employing such a hologram system, when the objective lens L is moved away from the optical disk OD, an FE signal as shown in FIG. 15 is detected in the case of a DVD-type optical disk. That is, the S-shaped waveform of the 0th-order light has a larger amplitude than the S-shaped waveform of the primary light. On the other hand, when the bifocal pickup is used for a CD optical disk, an FE signal as shown in FIG. 16 is detected. That is, the S-order waveform of the zero-order light and the first-order light has the same small amplitude. Thus, since the ratio of the 0th-order light and the 1st-order light is different between the DVD-type optical disc and the CD-type optical disc, these discs can be discriminated using this difference. This also applies to the AOD / Blu-ray bifocal pickup.

  In the above embodiment, the optical disk loaded in one drive includes a CD optical disk, a DVD optical disk, a Blu-ray standard optical disk, and an AOD standard optical disk. However, among these, the Blu-ray standard optical disc and the AOD standard optical disc are highly likely to be configured as a multi-drive that supports only one of them. Even in such a case, if the multi-drive supports only the Blu-ray of these standards, the focus search by the optical system of the optical disk of the Blu-ray standard is performed last. Further, in the case of a multi-drive that supports only AOD, the effect similar to that of the above-described embodiment can be obtained by performing the focus search by the optical system of the optical disc of the AOD standard last.

  In the embodiment described above, the disc search is performed by performing the focus search in order from the optical system having the long working distance WD, but the focus search does not necessarily have to be performed in the order from the optical system having the long working distance WD. . In short, by performing the focus search by the optical system of the optical disc of the standard with the shortest working distance WD, the effect according to the above embodiment can be obtained.

1 is a block diagram showing an embodiment of an optical disc drive apparatus according to the present invention. The block diagram which shows the specific structure of the pick-up of the apparatus of the embodiment. The block diagram which shows the specific structure of the servo amplifier of the apparatus of the embodiment. The flowchart which shows the whole process sequence about the procedure of disk discrimination | determination by the embodiment. 6 is a flowchart showing a disc discrimination procedure by an optical system of a DVD optical disc as a first stage of disc discrimination. 6 is a flowchart showing a disc discrimination procedure by an optical system of a CD optical disc as a second stage of disc discrimination. 9 is a flowchart showing a disc discrimination procedure by an optical system of an AOD standard optical disc as a third stage of disc discrimination. 10 is a flowchart showing a disc discrimination procedure by an optical system of a Blu-ray standard optical disc as a fourth stage of disc discrimination. The time chart which shows the FE signal example of a single-sided dual layer disk. The graph which compares and shows the FE signal aspect of each optical disk detected by the optical system of a DVD-type optical disk. The graph which compares and shows the FE signal aspect of each optical disk detected by the optical system of CD type | system | group optical disk. The graph which compares and shows the FE signal aspect of each optical disk detected by the optical system of the optical disk of AOD specification. The graph which compares and shows the FE signal aspect of each optical disk detected by the optical system of the optical disk of a Blu-ray standard. (A) is a part of an optical pickup for a DVD optical disk, (b) is a part of an optical pickup for a CD optical disk, and (c) is a part of a bifocal pickup for a DVD optical disk and a CD optical disk. FIG. 4 is a time chart showing an example of an FE signal when a focus search of a DVD optical disk is performed with the above-mentioned two-focus pickup. The time chart which shows the example of FE signal when performing the focus search of CD type | system | group optical disk with the same bifocal pickup. The schematic perspective view which shows the structure of the pick-up used for the conventional DVD drive. (A) is a lens driving mode, (b) is an FE signal, and (c) is a time chart showing transitions of an RF signal in accordance with a focus search.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Pickup, 110 ... Optical system of CD type optical disk, 111 ... Semiconductor laser oscillator, 112 ... Collimator lens, 113 ... Objective lens, 114 ... Beam splitter, 115 ... Light receiving element, 120 ... Optical system of DVD type optical disk, 121 ... Semiconductor laser oscillator, 122 ... collimator lens, 123 ... objective lens, 124 ... beam splitter, 125 ... light receiving element, 130 ... optical system of AOD optical disk, 131 ... semiconductor laser oscillator, 132 ... collimator lens, 133 ... objective lens, 134 DESCRIPTION OF SYMBOLS ... Beam splitter, 135 ... Light receiving element, 140 ... Optical system of Blu-ray optical disk, 141 ... Semiconductor laser oscillator, 142 ... Collimator lens, 143 ... Objective lens, 143 ... Objective lens, 144 ... Beam splitter, 145 ... Light receiving element 1 DESCRIPTION OF SYMBOLS 0 ... PDIC, 151 ... Selector, 200 ... Servo amplifier, 201, 202, 203 ... Adder, 204 ... Subtractor, 205, 206 ... Limiter, 207 ... Phase comparator, 300 ... System computer, 400 ... Encoder / decoder, 500 ... Interface (I / F), 600 ... Driver circuit, 700 ... Laser drive circuit, Amp ... Amplifier, L ... Objective lens, OD ... Optical disc, R ... Reflective layer (recording layer).

Claims (5)

An optical disc drive apparatus that performs discrimination of optical discs by a focus search for optical discs composed of a plurality of types of standards that are mounted on one drive,
An optical disc drive apparatus characterized in that a focus search is finally performed by an optical system of a standard having the shortest working distance which is a movable distance of an objective lens with respect to a mounted optical disc. The optical disc according to claim 1, wherein the optical disc composed of the plurality of types of standards includes a Blu-ray standard optical disc, and the optical system for performing the focus search at the end is an optical system corresponding to the Blu-ray standard optical disc. Drive device. The optical disc drive apparatus according to claim 1, wherein the optical disc composed of a plurality of types of standards includes an optical disc conforming to the AOD standard, and the optical system that performs the focus search last is an optical system corresponding to the optical disc conforming to the AOD standard. The optical system composed of a plurality of types of optical discs includes a Blu-ray standard optical disc and an AOD standard optical disc, and the optical system for performing the focus search at the end is an optical system corresponding to the Blu-ray standard optical disc. 2. An optical disk drive device according to 1. The optical disc drive apparatus according to any one of claims 1 to 4, wherein the focus search is sequentially performed from an optical system having a long working distance.

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