JP2006294226A - Optical disc device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disc device capable of preventing a collision with an objective lens even in the case of an optical disc provided with a projection part. <P>SOLUTION: The optical disc device is provided with: an optical pickup 6, which has a light source 23 which emits an optical beam 21 for irradiating an optical disc 100, at least one objective lens 22 for focusing the optical beam 21, and an actuator which shifts the objective lens 22 in a direction vertical to the optical disc 100; a transfer table 11 for transferring the optical pickup 6 in a disc diameter direction; a rim detection means 30 for detecting that an irradiation position of the optical beam 21 is over an edge section of the optical disc 100, in the case of shifting the optical pickup 6 from an inner circumference side to an outer circumference side of the disc for seek operation; and a control means 40 which shifts the objective lens 22 in a direction to be away from the optical disc 100 by the actuator when the irradiation position of the optical beam 21 is detected over the edge section of the optical disc 100, and shifts the optical pickup 6 to the disc inner circumference side by the transfer table 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical disc apparatus.

  Data recorded on the optical disk is reproduced by irradiating the rotating optical disk with a relatively weak light beam of a constant light quantity and detecting reflected light modulated by the optical disk.

  In a reproduction-only optical disc, information by pits is previously recorded in a spiral shape at the manufacturing stage of the optical disc. On the other hand, in a rewritable optical disk, a recording material film capable of optically recording / reproducing data is deposited on the surface of a substrate on which a track having spiral lands or grooves is formed by a method such as vapor deposition. Has been. When data is recorded on a rewritable optical disc, the optical disc is irradiated with a light beam whose amount of light is modulated in accordance with the data to be recorded, thereby changing the characteristics of the recording material film locally to write the data. Do.

  The pit depth, track depth, and recording material film thickness are smaller than the thickness of the optical disk substrate. For this reason, the portion of the optical disc where data is recorded constitutes a two-dimensional surface and may be referred to as a “recording surface” or an “information surface”. In this specification, considering that such a surface has a physical size in the depth direction, instead of using the phrase “recording surface (information surface)”, the “information layer” Use words. An optical disc has at least one such information layer. One information layer may actually include a plurality of layers such as a phase change material layer and a reflective layer.

  When reproducing data recorded on an optical disc or recording data on a recordable optical disc, the light beam must always be in a predetermined focused state on the target track in the information layer. For this purpose, “focus control” and “tracking control” are required. “Focus control” refers to the case where the position of the objective lens is referred to as the normal direction of the information surface (hereinafter referred to as the “depth direction of the substrate”) so that the focal point (focusing point) of the light beam is always located on the information layer There is control). On the other hand, the tracking control is to control the position of the objective lens in the radial direction of the optical disc (hereinafter referred to as “disc radial direction”) so that the spot of the light beam is located on a predetermined track.

  Conventionally, optical disks such as DVD (Digital Versatile Disc) -ROM, DVD-RAM, DVD-RW, DVD-R, DVD + RW, and DVD + R have been put to practical use as high-density and large-capacity optical disks. Also, CD (Compact Disc) is still popular. Currently, development and commercialization of next-generation optical discs such as Blu-ray Disc (BD) and HD-DVD, which have higher density and larger capacity than these optical discs, are being promoted.

  In order to increase the recording density of the optical disc, it is preferable to reduce the spot diameter of the light beam focused on the data surface of the optical disc. Since the spot diameter of the light beam is inversely proportional to the numerical aperture NA of the objective lens used to focus the light beam, the spot diameter of the light beam can be reduced by increasing the numerical aperture NA of the objective lens. It is.

  The numerical aperture NA of the objective lens is inversely proportional to the focal length of the objective lens. For this reason, in an optical disc apparatus using an objective lens having a high numerical aperture NA, the distance (working distance) from the objective lens to the optical disc becomes extremely short. The working distance in a DVD player (NA: 0.6) is 0.6 to 0.8 mm, whereas the working distance in a BD player (NA: 0.8 or more) is 0.1 to 0.3 mm. is there.

  As described above, when the working distance decreases as the numerical aperture NA increases, there arises a disadvantage that the objective lens easily collides with the optical disc. It is necessary to avoid such a “collision” and keep the distance between the objective lens and the optical disc within a predetermined range. As described above, when the focus control is performed, the position of the objective lens is controlled so that the focus (focusing point) position of the light beam is always located on the information layer. Hard to occur. Further, when the servo loop for focus control is lost for some reason during recording / reproducing operation (out of focus), an avoidance process is performed immediately away from the optical disk as much as possible. However, there is a risk that the objective lens collides with the optical disc before the focus control is started again. Hereinafter, this point will be described.

  FIG. 1A schematically shows how the distance between the surface 100a of the optical disc 100 and the objective lens 22 gradually decreases. The optical disc 100 includes a substrate body 112 that is transparent to laser light, an information layer 114 formed on the substrate body 112, and a protective layer (cover layer) 116 that covers the information layer 114. The illustrated optical disc 100 corresponds to a BD, and the thickness of the cover layer 16 is about 0.1 mm.

  In FIG. 1A, the case where the focal position of the laser beam 21 is located on the surface 100a of the optical disc, the case where it is located on the information layer 114, and the case where it is located inside the substrate body 112 are shown simultaneously. Yes. FIG. 1B schematically shows a focus error signal (FE) obtained when the focal position of the laser beam 21 changes with time. The focus error signal changes so as to show a small S-shaped curve when the focal point of the laser beam 21 passes through the surface 100a of the optical disc 100. FIG. 1C schematically shows the amplitude of the reproduction signal (RF) obtained when the focal position of the laser beam 21 changes with time. When the focal point of the laser beam 21 passes through the information layer 114 of the optical disc 100, the reproduction signal has a significant value that is not zero. Therefore, it can be determined that the focal point of the laser light 21 is located in the vicinity of the information layer 114 when both the reproduction signal and the focus error signal exhibit an amplitude of a predetermined level or more. In such a case, when the focus servo is turned on, the position of the objective lens 22 is controlled so that the focus error signal is always zero. As described above, when the S-curve of the focus error signal is detected while the objective lens 22 is approached to the optical disc 100 for obtaining the information layer 114, the focus is near the center of the S-curve (near the zero cross point of the focus error signal). The operation of setting the servo to the ON state is referred to as “focus pull-in”.

  Since the section (detection section) in which the S-curve appears in the focus error signal is limited to a relatively narrow range (several μm), the focus position of the objective lens 22 is set on the information layer 114 of the optical disc 100 to perform focus pull-in. It is necessary to perform an operation to bring the target information layer 114 close to the vicinity and within the detection section. As described above, the operation of starting the objective lens 22 from a position away from the optical disc 100 and gradually approaching it in order to detect the S-shaped curve may be referred to as “focus search”. Since the position of the objective lens 22 in the optical axis direction is adjusted by the lens actuator in the optical pickup, the objective lens 22 is gradually moved to the optical disk by gradually increasing the drive current supplied to the lens actuator during the focus search. 100. At this time, if an S-shaped curve appears in the focus error signal, it can be determined that the target information layer 114 has entered the detection section. In that case, the servo operation is started, and the magnitude of the drive current supplied to the focus actuator is controlled so that the value of the S-curve of the focus error signal becomes zero. A series of operations for performing such focus servo pull-in may be referred to as “focus on processing”.

  When performing the focus-on process, if the objective lens 22 is moved at a high speed in the optical axis direction until an S-shaped curve appears in the focus error signal, the focal point of the light beam 21 crosses the information layer 114 of the optical disc 100 in a short time. For this reason, the objective lens 22 may be further brought closer to the optical disc 100 without correctly detecting the S-shaped curve. In this case, the objective lens 22 collides with the optical disc 100. Such a problem can be solved to some extent by lowering the moving speed of the objective lens 22, but if there are scratches or dust on the optical disc 100, the S-curve cannot be detected correctly. There is.

Patent Document 1 discloses a method for preventing an objective lens from colliding with an optical disk even when detection of an information layer fails during focus-on processing and focus control cannot be started properly. . The optical disc apparatus disclosed in Patent Document 1 stores the drive voltage of the actuator, and turns off the focus drive voltage when the drive voltage of the actuator exceeds a predetermined level during the focus-on process. By doing so, even if the focus search fails due to dust or scratches attached to the surface of the optical disc, the focus search is stopped before the objective lens collides with the optical disc.
JP-A-11-120599

  A rim region is formed on the outermost periphery of an optical disk such as a DVD-RAM or a BD. The rim region functions to protect the data portion of the optical disc from dust, dust, and scratches when these optical discs are taken out of the cartridge or in a bare state. The configuration of the rim area is defined by, for example, Standard ECMA-330 (120 mm and 80 mm DVD Rewritable Disk (DVD-RAM)).

  FIG. 2 shows the configuration of the rim area in the DVD-RAM. The optical disc 100 shown in FIG. 2 includes a protruding portion 102 having a configuration defined by Standard ECMA-330. The protrusion 102 is formed between the position of the radius d1 and the position of the radius d2 from the center of the disk, and the thickness thereof is relatively increased as compared with the majority of the optical disk 100. The amount of protrusion of the protrusion 102 from the disk surface is indicated by h1.

  When the optical disc 100 is a 120 mm disc, d1, d2, and h1 are 120.00 mm ± 0.30 mm, 117.00 mm ± 0.20 mm, and 0.20 mm (max), respectively. On the other hand, when the optical disc 100 is an 80 mm disc, d1, d2, and h1 are 80.00 mm ± 0.30 mm, 76.80 mm ± 0.20 mm, and 0.20 mm (max), respectively.

  A region where the protrusion 102 is formed on the optical disk 100, that is, a ring-shaped region sandwiched between the position of the radius d1 and the position of the radius d2 from the center of the disk is the rim region 101.

  Thus, in the rim region 101, the surface of the optical disc 100 protrudes by 0.2 mm at the maximum toward the objective lens, and the working distance is 0.2 mm (= h1) shorter than the other regions of the optical disc 100. . In addition, since the rim region 101 is located at the outermost peripheral portion of the optical disc 100, the influence of the surface blur due to the warp of the optical disc 100 is large, and the rim region 101 easily collides with the objective lens. Therefore, even if the movement of the objective lens is restricted by the focus drive voltage in order to avoid the collision, the objective lens prevents the objective lens from colliding with the optical disc 100 in the rim region 101 during the focus-on process. It is difficult.

  Further, according to the study of the present inventor, when the irradiation position of the light beam exceeds the outer peripheral edge of the optical disk and jumps to a region where the optical disk 100 does not exist during the seek operation, the light beam is returned when the irradiation position of the light beam is returned onto the optical disk. It has been found that the risk of the pickup colliding with the optical disc 100 increases. FIGS. 3A and 3B show a state where the irradiation position of the light beam exceeds the protruding portion 102 of the optical disc 100 during the seek operation. A lens protection unit 230 is provided in the vicinity of the objective lens 22. In the present specification, when a light beam irradiation position exceeds the outer peripheral edge of the optical disc 100 during a seek operation and jumps out to an area where the optical disc 100 does not exist is referred to as “overrun”. When such an overrun occurs, it is impossible to generate a focus error signal or a tracking error signal. Normally, the optical pickup is moved horizontally (traversed) while holding the objective lens at the position immediately before the overrun. It is necessary to return the irradiation position of the beam onto the optical disc 100. However, when the optical pickup is moved horizontally from the position shown in FIG. 3B toward the inner periphery of the disc, the objective lens 22 or the lens protection unit 230 protrudes from the optical disc 100 as shown in FIG. There is a risk that the optical disk 100 or the optical pickup may be damaged by colliding with the section 102.

  The danger that a part of the optical pickup collides with the optical disk 100 in this way is also when the optical disk 100 having a diameter of 80 mm is fitted into the adapter 150 and used as shown in FIGS. 4 (a) and 4 (b). Prone to occur. The adapter 150 is a ring-shaped device used for adapting the optical disc 100 having a diameter of 80 mm to an optical disc device dedicated to the optical disc having a diameter of 120 mm. The adapter 150 has a protrusion (claw portion) 152 that holds the optical disc 100. Is provided. This protrusion 152 exists at a position of about 40 mm from the center of the disk. When a seek operation is performed on the optical disk 100 having a diameter of 80 mm, overrun is likely to occur. Therefore, when the optical pickup includes a high NA lens with a short working distance, a collision with the protrusion 152 of the adapter 150 is particularly serious. It tends to occur.

  Even when overrun does not occur, if the focus servo is lost for some reason during normal reproduction or recording operation, the optical disc 100 may collide with the optical pickup. As shown in FIG. 5A, when a part of the optical pickup (for example, the lens protection unit 230) is present in a region facing the protruding portion 102 of the optical disc 100 and the focus servo is removed, a focus-on process is performed. Therefore, as shown in FIG. 5B, it is necessary to once move the objective lens 22 away from the optical disc 100. In order to start the focus control again, the focus search is performed while the objective lens 22 is brought close to the optical disc 100 as shown in FIG. At this time, there is a possibility that the objective lens 22 gets too close to the optical disc 100 and a part of the optical pickup (for example, the lens protection unit 230) collides with the protrusion 102.

  FIG. 12 shows a part of an optical pickup that integrally includes an objective lens 9 for DVD and an objective lens 22 for BD. These lenses 9 and 22 are integrally driven by an actuator. For this reason, there is a possibility that the high NA objective lens 22 or the lens protection unit 230 may collide with the protruding portion 102 of the optical disc 100 when data is recorded / reproduced with respect to the DVD using the objective lens 9 that is hard to collide. is there. Therefore, when the optical pickup includes both the DVD objective lens 9 and the BD objective lens 22, a collision with the protrusion 102 of the optical disc 100 occurs even when an operation is performed on the DVD optical disc. There is a danger to do.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical disc apparatus capable of preventing a collision with an objective lens even with respect to an optical disc having a protrusion.

  An optical disc apparatus according to the present invention includes a light source that emits a light beam for irradiating an optical disc, at least one objective lens that focuses the light beam, and the objective lens is moved in a direction perpendicular to the optical disc. An optical pickup having an actuator capable of moving, a transfer means for moving the optical pickup in the radial direction of the optical disk, and a case where the optical pickup is moved from the inner peripheral side to the outer peripheral side of the optical disk by the transfer means for seek operation And detecting means for detecting that the irradiation position of the light beam has passed the end of the optical disc, and detecting that the irradiation position of the light beam has passed the end of the optical disc, The objective lens is moved away from the optical disk, and the transfer hand And control means for moving the optical pickup to the inner circumference side of the optical disc by.

  In a preferred embodiment, when the actuator moves the objective lens in a direction away from the optical disc when detecting that the irradiation position of the light beam has passed the end of the optical disc, the control means includes: The optical pickup is moved away from the optical disc by a distance longer than the distance corresponding to the height of the protruding portion of the optical disc.

  In a preferred embodiment, the control means performs a focus-on process after moving the optical pickup to the inner peripheral side with respect to the protruding portion of the optical disc.

  In a preferred embodiment, the control means changes a distance for moving the objective lens in a direction away from the optical disc in accordance with a diameter of the optical disc.

  In a preferred embodiment, the distance when the diameter of the optical disc is 80 mm is set shorter than the moving distance when the optical disc is 120 mm.

  In a preferred embodiment, the detection means can detect whether or not the objective lens is located in a region facing the protruding portion of the optical disc.

  In a preferred embodiment, if the objective lens is located in a region facing the protruding portion of the optical disc when the focus servo is removed during a recording or reproducing operation, the control means moves the objective lens to the optical disc by the actuator. The optical pickup is moved in a direction away from the projection and on the inner peripheral side of the protrusion.

  In a preferred embodiment, after the control means moves the optical pickup to the inner peripheral side, a focus-on process is performed.

  In a preferred embodiment, the at least one objective lens includes a first objective lens exhibiting a first numerical aperture and a second objective lens exhibiting a second numerical aperture higher than the first numerical aperture.

  In a preferred embodiment, the second numerical aperture is 0.8 or more.

  An optical disk apparatus driving method according to the present invention is an optical disk apparatus driving method including an optical pickup having an objective lens that focuses an optical beam on the optical disk, and the optical pickup is moved from the inner periphery side of the optical disk for a seek operation. When the irradiation position of the light beam exceeds the end of the optical disc during the seek operation and the step of moving to the outer peripheral side, the objective lens is moved away from the optical disc, and the optical pickup is moved Moving to the inner peripheral side of the optical disc.

  When the control device for the optical disk apparatus according to the present invention detects that the irradiation position of the light beam exceeds the end of the optical disk, the actuator in the optical pickup moves the objective lens in the optical pickup away from the optical disk. The optical pickup is moved to the inner peripheral side of the optical disc.

  Another optical disk apparatus of the present invention includes a light source that emits a light beam for irradiating an optical disk, at least one objective lens that focuses the light beam, and the objective lens that moves in a direction perpendicular to the optical disk. An optical pickup having an actuator that can be moved, a transfer means for moving the optical pickup in the radial direction of the optical disk, and for the seek operation, the optical pickup is moved from the inner peripheral side to the outer peripheral side of the optical disk by the transfer means And detecting means for detecting that the irradiation position of the light beam has passed the end portion of the optical disc, and detecting the fact that the irradiation position of the light beam has passed the end portion of the optical disc, To move the objective lens away from the optical disc and to move the objective lens. Control means for moving the optical pickup to the inner circumference side of the optical disk by means, and the control means determines the retraction amount when the objective lens is moved away from the optical disk by the actuator. Is larger when an 80 mm diameter disk with an adapter is set than when the is set.

  In a preferred embodiment, when the 80 mm diameter disk is set, the control means makes the retraction amount larger than the retraction amount when the 120 mm diameter disk is set, regardless of whether an adapter is attached or not.

  Still another optical disc apparatus according to the present invention includes at least one light source that emits a light beam for irradiating an optical disc, a plurality of objective lenses having different numerical apertures, and the objective lens in a direction perpendicular to the optical disc. An optical pickup having an actuator that can be moved, a transfer means for moving the optical pickup in the radial direction of the optical disc, and detecting whether at least a part of the optical pickup is located opposite to a rim region of the optical disc And detecting that at least a part of the optical pickup is located in the rim area when performing a focus-on process using a detection means that performs an objective lens having a relatively low numerical aperture among the plurality of objective lenses. In this case, the objective lens used for the focus-on process and a higher numerical aperture than the objective lens As out of the region where the objective lens facing the rim region, and a control means for moving the optical pickup to the inner circumference side of the optical disk by the transport means.

  In a preferred embodiment, the optical pickup includes a lens protection portion on an outer peripheral side of the objective lens, and the control unit detects that at least a part of the optical pickup is located in the rim region. The optical pickup is moved to the inner peripheral side of the optical disc by the transfer means so that the lens protection part is separated from the region facing the rim region.

  In the optical disk apparatus according to the present invention, when the optical pickup moves beyond the outer peripheral edge of the optical disk when the seek operation is performed in the outer peripheral direction of the optical disk, the objective lens moves the rim region when the optical pickup moves in the inner peripheral direction. To avoid collision with the optical disc. Further, when performing the focus-on process, it is detected whether or not the position of the optical pickup is located in a region facing the protruding portion of the optical disk, and when located in the opposed region, the position of the optical pickup is changed. The objective lens is prevented from colliding with the optical disk.

  First, a characteristic operation in the optical disc apparatus according to the present invention will be described with reference to FIGS.

  FIG. 6A schematically shows the movement of the objective lens 22 during the seek operation. It is assumed that the objective lens 22 is moved in the horizontal direction in the figure from the inner peripheral side to the outer peripheral side of the optical disc 100 by the traverse operation of the optical pickup. As shown in FIG. 6B, when the irradiation position of the light beam exceeds the end of the optical disk 100, the detection means detects the occurrence of “overrun”, and the control means moves the objective lens 22 away from the optical disk 100. Move in the direction (arrow A). Thereafter, the optical pickup (not shown) is moved to the inner peripheral side of the optical disc 100, and the objective lens 22 is also moved to the inner peripheral side of the disc together with the optical pickup (arrow B).

  After the objective lens 22 has moved to the inner peripheral side from the region facing the protruding portion 102 of the optical disc 100, an operation of bringing the objective lens 22 closer to the optical disc 100 is started for the focus-on process (arrow C).

  As described above, in the optical disc apparatus of the present invention, when an overrun occurs, the objective lens 22 is detoured so as to avoid the protruding portion 102 of the optical disc 100. Therefore, an objective lens having a large numerical aperture NA and a short focal length is adopted. Even in this case, it is possible to avoid a collision with the optical disc 100 and realize a highly reliable operation.

  In another aspect of the present invention, an appropriate avoidance operation is executed even when no overrun has occurred. That is, as shown in FIG. 7B, when the focus servo is removed when a part of the optical pickup (for example, the lens protection unit 230) is located in a region facing the protrusion 102 as shown in FIG. After the objective lens 22 is moved away from the optical disc 100 (arrow A), the position of the objective lens is moved to the inner periphery side of the disc as shown in FIG. 7C (arrow B). Thereafter, even when an operation (arrow C) for bringing the objective lens 22 closer to the optical disc 100 for a focus search is started, it is possible to avoid a collision with the protruding portion 102 of the optical disc 100.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
First, a first embodiment of an optical disc apparatus according to the present invention will be described with reference to FIG. FIG. 8 shows the configuration of the optical disc apparatus of the present embodiment.

  The optical disk apparatus according to the present embodiment is an optical disk apparatus (three-wavelength multidrive) capable of reading data from a plurality of types of optical disks and writing data on such optical disks. Applicable optical disks of the present embodiment include rewritable optical disks such as Blu-ray disks, DVD-RWs, and DVD-RAMs, and write-once optical disks such as CD-Rs and DVD-R disks. Further, the diameter of the optical disk is not limited to 120 mm, and may be 80 mm.

  This optical disk apparatus includes a disk motor (spindle motor) 2 that rotates the optical disk 100, an optical pickup 6 that accesses a desired track of the optical disk 100, and a control unit 40 that controls the operations of the optical pickup 6 and the disk motor 2 and the like. In the figure, a broken line portion) is provided.

  The disk motor 2 can rotate the optical disk 100 at a predetermined rotation speed (per minute). The recording / reproducing system of the optical disc 100 is divided into a CLV system (including a zone CLV system) that performs recording / reproduction at a constant linear velocity and a CAV system (including a zone CAV system) that performs recording / reproduction at a constant angular velocity. Recording and reproduction of music, image information, and the like are desirably performed at a constant data transfer rate, and the CLV method is suitable. In the CLV method, recording and reproduction are performed at a constant linear velocity. Therefore, when the light beam is scanned on the track on the inner circumference side, control is performed so that the rotation speed of the optical disc 100 is increased, and the light beam scans the outer circumference side. Control is performed so that the rotational speed of the optical disc 100 is lowered. On the other hand, in the zone CLV method, the optical disk 100 is divided into a plurality of zones in the radial direction, the rotation speed is constant within the zone, and the average linear velocity is constant by changing the rotation speed between the zones. I have control.

  The rotation speed of the optical disk 100 by the disk motor 2 is controlled by the rotation controller 3, and the actual rotation speed is detected by the rotation speed detector 4. The rotation speed detection unit 4 sends a detection value signal indicating the detected rotation speed to the controller 5.

  The optical pickup 6 includes a light source (red semiconductor laser 7 and blue semiconductor laser 23) that emits a plurality of light beams 8 and 21 having different wavelengths, an objective lens 9 and 22 that focuses the light beams 8 and 21, and an optical disc 100. A photodetector 16 that generates an electrical signal based on at least a part of the reflected light beams 8 and 21 is provided and supported by the transfer table 11. Since the optical disk device of the present embodiment is also compatible with CDs, the optical pickup 6 also includes an infrared laser (not shown) that emits an infrared light beam used for CD irradiation. . However, illustration is omitted for simplicity.

  Although not shown in FIG. 8, the optical pickup 6 is provided with a lens protection unit similar to the lens protection unit 230 shown in FIG.

  The red laser 7 and the blue laser 23 which are light sources are connected to the red laser driving unit 10 and the blue laser driving unit 24, respectively. The red laser driver 10 controls the red semiconductor laser 7 so that the power of the red light beam 8 is suitable for recording, erasing and reproducing levels. On the other hand, the blue laser driving unit 24 controls the blue semiconductor laser 23 so that the power of the blue light beam 21 is suitable for the recording, erasing and reproducing levels.

  The red light beam 8 is used to irradiate DVD, and the blue light beam 21 is used to irradiate BD. The CD is irradiated with an infrared light beam emitted from an infrared laser (not shown). The infrared laser is controlled in the same manner as other lasers.

  The controller 40 including the controller 5 as a main component performs a focus control operation and a tracking control operation by controlling the operations of the optical pickup 6, the disk motor 2, and other components. Each functional block constituting the control unit 40 may be realized by hardware, or may be realized by a combination of hardware and software. At least a part of the control unit 40 may be incorporated in the optical disc apparatus as a semiconductor integrated circuit device. The control unit 40 may be realized on one semiconductor chip, or may be realized separately on a plurality of semiconductor chips. The operation of the control unit 40 can be defined by a program stored in a memory in the optical disc apparatus. By changing this program, details of the operation of the control unit 40 (for example, parameters such as the vertical movement distance of the lens) can be changed.

  The controller 5 of this embodiment includes a rim detection unit 30 that detects whether or not the optical pickup 6 is located at a position facing the rim region 101 of the optical disc 100. The rim detection unit 30 has an overrun. It can also be detected.

  The optical pickup 6 described above can be moved (traverse) along the disk radial direction by a transfer table 11 driven by a motor (not shown). The operation of the transfer table 11 is controlled by the transfer control unit 13. Normally, when the optical disc 100 is loaded in the optical disc apparatus, the transfer table 11 moves the optical pickup 6 to the innermost circumference side of the disc and positions the focal point of the light beam in the innermost circumference area (management area) of the optical disc 100. To work. In order to control the movement of the optical pickup 6 at high speed, it is preferable to configure the transfer table 11 using a linear motor.

  The radial position (light beam irradiation position) of the light beam spot formed on the optical disc 100 is roughly determined by the transfer table 11 and then finely determined by the lens actuator in the optical pickup 6. The objective lenses 9 and 22 of the optical pickup 6 are integrally held as shown in FIG. 12 and are integrally driven by the lens actuator 240. Therefore, when the optical actuator 100 is irradiated with the light beam 8, if the lens actuator operates to adjust the position of the lens 9, the position of the lens 22 will inevitably change.

  The radial position of the light beam spot on the optical disc 100 is detected by the position detector 12 attached to the transfer table 11. A detection value signal indicating the detected radial position is sent from the position detection unit 12 to the controller 5. The rim detection unit 30 of the controller 5 obtains information on the radial position of the light beam spot based on the signal from the position detection unit 12 and determines whether the light beam spot is in the rim region 101, in other words, the optical pickup 6. It is possible to determine whether or not is in a position facing the rim region 101.

  When a transfer command such as the target position and the number of rotations at the target position is sent from the controller 5 to the seek control unit 19, control such as a transfer command of the optical pickup 6 to the target position is sent from the seek control unit 19 to the transfer control unit 13. A signal is sent. At this time, in order to realize the rotation speed at the target position, a control signal such as a rotation speed change command for the disk motor 2 is sent from the seek control section 19 to the rotation control section 3 to move the transfer table 11 and the disk motor. The rotational speed of 2 is controlled.

  The focus control unit 14 positions the focal point of the light beams 8 and 21 on a desired information layer of the optical disc 100, and the tracking control unit 15 positions the focal point of the light beams 8 and 21 on the target track. By focus control and tracking control, it becomes possible for the focusing point of the light beam 8 or 21 to always follow the target track of the target information layer even while the optical disc 100 rotates at high speed. . As the optical disc 100 rotates, the optical disc 100 undergoes a surface shake, so that the distance between the optical pickup 6 and the optical disc 100 varies. When the focus control is functioning, the axial position of the objective lenses 9 and 22 is finely adjusted by the actuator 240 (FIG. 12) in the optical pickup 6, and the focusing point of the light beams 8 and 21 is always the target information layer. Can be located on top.

  Light reflected by the optical disk 100 of the light beams 8 and 21 is converted into an electric signal by the light detection unit 16. After the electric signal is amplified by the preamplifier 17, the reproduction signal processing unit 18 demodulates the information, the focus control unit 14 feedbacks the focus error detection, and the tracking control for tracking error detection feedback. It is sent to the part 15 respectively. The reproduction signal processing unit 18 demodulates the information of the electric signal and measures the amount of reflected light, and sends the result to the controller 5.

  The focus control unit 14 and the tracking control unit 15 control the actuators 240 (FIG. 12) in the optical pickup 6 so as to minimize the absolute values of the focus error signal and the tracking error signal, respectively. Adjust the position (servo control).

  Next, with reference to FIG. 9, processing when “overrun” occurs during the seek operation will be described.

  First, in step 301 in FIG. 9, the optical pickup 6 is moved in the outer peripheral direction of the optical disc 100 by the transfer table 11 for a seek operation. In step 302, the position detector 12 acquires the position of the optical pickup 6 from the transfer table 11. The position of the optical pickup 6 can be acquired based on the output of the position detector 12. When the transfer table 11 is operated by a stepping motor, the position of the optical pickup 6 can be determined by counting the driving pulses of the stepping motor by the position detection unit 12. When the transfer table 11 is operated by a DC motor, the position of the optical pickup 6 can be determined by counting drive pulses of a linear encoder or the like with the position detector 12. Alternatively, the position of the optical pickup corresponding to the irradiation position of the light beam spot may be determined based on the address acquired from the optical disc 100.

  In step 303, the rim detection unit 30 determines whether or not an overrun has occurred based on the position of the optical pickup 6 acquired in step 302. If an overrun has occurred, the process proceeds to step 304. If no overrun has occurred, the process proceeds to step 308. Here, the determination of whether or not overrun has occurred can be performed by the following methods (1) and (2), for example.

  (1) Based on the radial position information of the optical pickup 6, it is determined that an overrun has occurred when the optical pickup position is on the outer peripheral side, for example, from the radial position of 58.5 mm. Here, “radius position 58.5 mm” corresponds to the outer peripheral radius position of the rim region in the case of a BD having a diameter of 120 mm on the optical disc 100. Here, the “optical pickup position” corresponds to the radial position of the center of the objective lens used for irradiation of the light beam.

  (2) When the amount of reflected light obtained from the reproduction signal processing unit 18 is not more than a predetermined level (for example, not more than 50% of the amount of reflected light when servo control is performed), it is determined that an overrun has occurred.

  In step 304, the objective lenses 9 and 22 are moved (retracted) away from the optical disc 100 by the lens actuator 240 (arrow A in FIG. 6B). The distance of this movement (lens vertical movement amount = retraction amount) is set to a size such that the objective lenses 9 and 22 and the rim region 101 of the optical disc 100 do not collide. Specifically, it is determined by adding a value (margin) considering the amount of surface deflection of the optical disc 100 to the maximum protrusion amount (for example, 0.2 mm) of the rim region 101. When the diameter of the optical disc 100 is 120 mm, the surface blur region in the rim region 101 is about 0.3 mm, for example. When the diameter of the optical disc 100 is 80 mm, the surface blur region in the rim region 101 is about 0.2 mm, for example. It is. As described above, since the amount of surface blur also varies depending on the size of the optical disc 100, the retract amount of the objective lens may be changed according to the size of the optical disc. Thus, the retracting amount of the objective lens may be set to 0.5 mm when the diameter of the optical disc 100 is 120 mm, and may be set to 0.4 mm when the diameter is 80 mm. Further, in the case of an 80 mm disc with an adapter attached, since the protrusion amount (for example, 0.5 mm) of the protrusion 152 (FIG. 4) is larger than the protrusion amount of the rim region 101, the retraction amount of the objective lens is set as the protrusion. You may set to the value 0.9mm which added the protrusion amount of 152, and surface blurring. However, when the lens protection unit 230 is provided, the retraction amount may be determined in consideration of the height (for example, 20 to 70 μm) of the portion where the lens protection unit 230 protrudes from the objective lens 22. preferable. This is because when the optical pickup 6 is moved to the inner peripheral side of the optical disc 100, the collision between the lens protection unit 230 and the rim region 101 or the adapter is surely avoided.

  In step 305, the optical pickup 6 is moved to the inner peripheral side along the radial direction of the optical disc 100 by the transfer table 11 (arrow B in FIG. 6B). The moving distance is determined so that the optical pickup 6 is located on the inner peripheral side with respect to the radial position of the rim region 101. The range of the rim area 101 may be obtained by adding a margin determined by the feed resolution of the transfer table 11 to the radial size (width) of the actual rim area 101 on the optical disc 100.

  The movement destination of the optical pickup 6 is arbitrary as long as it is located on the inner peripheral side with respect to the rim region 101. However, if it is moved to a position close to the seek target track, it is necessary to move to the target track. Time can be shortened. Note that the movement (traverse) of the arrow B may be started before the movement of the objective lens indicated by the arrow A is completed.

  In step 306, the objective lenses 9 and 22 are brought close to the optical disc 100 by the action of the focus control unit 14 (arrow C in FIG. 6B), and a focus-on process is executed. Since the focus-on process is as described above, detailed description thereof will not be repeated here.

  In step 307, the position of the optical pickup 6 is acquired by the same method as that used in step 302. In step 308, it is determined whether or not the position of the optical pickup 6 acquired in step 302 or step 307 matches the position of the target track. If it matches the position of the target track, the seek process is completed. If not, the process returns to step 301 and the same process is repeated.

  The confirmation of completion of the seek process may be performed by acquiring an address at the current optical pickup position in step 307 and determining whether or not the target address matches with the target address in step 308.

  The rim detection unit 30 in the present embodiment detects that the irradiation position of the light beam has passed the end of the optical disk when the optical pickup 6 is moved from the inner peripheral side to the outer peripheral side of the optical disk for a seek operation. It functions as a detection means.

(Embodiment 2)
Next, a second embodiment of the optical disc apparatus according to the present invention will be described with reference to FIG. The basic configuration of the optical disc apparatus of the present embodiment is the same as the configuration of the optical disc apparatus shown in FIG. The difference is in the operation flow.

  As described above, when focus control is performed, the focusing point of the light beam 8 or the light beam 21 can always follow the target information layer while the optical disc 100 is rotating at high speed. become. However, the focus servo may be lost due to scratches or dust on the optical disc 100 or an impact from the outside of the apparatus. In this case, it is necessary to perform an operation (retry) for starting focus control again. In the present embodiment, a retry method when the focus servo is lost due to a cause different from overrun will be described. Hereinafter, for simplicity, the case where the optical pickup 6 includes only one objective lens (for example, the objective lens 22 for BD) will be described first.

  First, in step 201 in FIG. 10, the current position of the optical pickup 6 is acquired. Since the method for obtaining the position of the optical pickup 6 is the same as that described in the first embodiment, the description thereof is omitted.

  In step 202, based on the position of the optical pickup 6 determined in step 201, it is determined whether or not the objective lens 22 is in an area facing the rim area 101 of the optical disc 100. When the objective lens 22 is in the region facing the rim region 101, the process proceeds to step 203. If it is not in the area facing the rim area 101, the process proceeds to step 205. The rim detection unit 30 performs the above determination. Specifically, based on the position information of the optical pickup 6 (information indicating the disk radius position), the total value of the disk radius position and the lens radius at the center of the objective lens 22 is, for example, a disk radius position of 58.5 to 60.0 mm. Is within the area facing the rim area 101, the objective lens 22 is determined to be in the area facing the rim area 101. Here, “disc radius position 58.5 to 60.0 mm” corresponds to the rim region 101 in the case of a BD having a diameter of 120 mm of the optical disc 100.

  In step 203, the objective lenses 9 and 22 are moved (retracted) in the direction away from the optical disc 100 by the lens actuator 240 (FIG. 12). The retraction amount (lens vertical movement amount) is set to a size such that the objective lenses 9 and 22 and the rim region 101 of the optical disc 100 do not collide as in the first embodiment. Therefore, it is preferable to set the retraction amount to a different value depending on the radial position of the rim region 101 (the diameter of the optical disc 100).

  In step 204, the optical pickup 6 is moved to the inner peripheral side along the radial direction of the optical disc 100 by the transfer table 11. This moving distance (horizontal moving distance) is determined so that the outer peripheral edge of the objective lens 22 is positioned on the inner peripheral side with respect to the radial position of the rim region 101. That is, the horizontal movement distance of the optical pickup 6 is determined so that the total value of “the radius position of the center of the objective lens 22” and “the lens radius” is smaller than the radius position of the rim region 101. From the viewpoint of preventing a collision with the rim region 101, it is preferable to increase the horizontal movement distance of the optical pickup 6, but in order to shorten the time until the recording / reproducing operation is restarted, when the focus servo is released. It is preferable to perform focus on in the vicinity of the light beam irradiation position. Therefore, the optical pickup 6 satisfies the condition that the outer peripheral edge of the objective lens 22 is positioned on the inner peripheral side with respect to the rim region 101, and is as much as possible at a position determined by the address acquired before the focus servo is released. It is preferable to move it to a close position.

  The “horizontal movement amount” to the inner peripheral side of the optical pickup 6 is preferably determined in consideration of disk eccentricity. Considering the width of the rim region 101 (for example, 1.5 mm), disk eccentricity (for example, 37.5 μm), spindle motor shaft runout (for example, 50 μm), lens radius (for example, 1 to 1.6 mmmm), etc. Is preferably set to a value larger than the value obtained by adding these numerical values.

  In the above description, the case where the optical pickup 6 includes only one objective lens 22 is targeted. However, hereinafter, the case where the optical pickup 6 includes the DVD objective lens 9 and the BD objective lens 22 will be described. .

  The arrangement relationship between the DVD objective lens 9 and the BD objective lens 22 in the optical pickup 6 can take two greatly different modes as shown in FIGS. As shown in FIG. 13A, when the two objective lenses 9 and 22 are arranged in the radial direction of the optical disc 100 and the BD objective lens 22 is located on the outer peripheral side, the DVD objective lens 9 Even when a light beam is irradiated onto a DVD, as is apparent from FIG. 12, there is a risk that an unused BD objective lens 22 collides with the rim 102. Therefore, when the focus servo is released for some reason and the objective lens 9 or 22 is brought close to the optical disc 100 for the focus-on process after the optical pickup 6 is moved away from the optical disc 100 for retraction, the objective lens for BD is used. It is necessary to move the optical pickup 6 horizontally to a position where 22 does not collide with the rim 102.

  In this way, the distance (horizontal movement amount) for moving the optical pickup horizontally takes into account the position of the dangerous portion of the optical pickup 6 that is likely to collide with the rim 102 of the optical disc 100, and the dangerous portion is the rim. It is preferable to be determined so as to be closer to the inner circumference side than the region 101.

  When the optical pickup 6 has a configuration in which the objective lens 22 for BD is positioned on the outer peripheral side than the objective lens 9 for DVD, when the DVD is accessed by the objective lens 9 for DVD, disk eccentricity, etc. It is preferable to add a “correction amount” in consideration of the arrangement relationship of the objective lenses 9 and 22 to the “horizontal movement amount” determined in consideration of the above.

  In the arrangement shown in FIG. 13A, this correction amount is defined by the difference between the radial position of the outermost peripheral portion of the objective lens 9 and the radial position of the outermost peripheral portion of the objective lens 22.

  Next, consider a case where two objective lenses 9 and 22 are arranged in the circumferential direction of the optical disc 100 as shown in FIG. In this case, even when the center of the DVD objective lens 9 is located on the inner peripheral side of the rim region 101, the center of the BD objective lens 22 is located in the rim region 101. In the example shown in FIG. 13C, the center of the DVD objective lens 9 is at the radial position 58.3 mm, and the center of the BD objective lens 22 is at the radial position 58.5 mm. However, in such a case, since the radius of the objective lens 22 for BD is smaller than the radius of the objective lens 9 for DVD, the outermost peripheral part of the objective lens 9 for DVD is on the inner peripheral side with respect to the rim region 101. If positioned, the outermost peripheral portion of the objective lens 22 for BD is also positioned on the inner peripheral side with respect to the rim region 101. For this reason, the arrangement of FIG. 13B has an advantage that it is easier to avoid a collision between the BD objective lens 22 and the rim 102 than the arrangement of FIG.

  Next, the collision between the lens protection unit 230 and the rim 102 will be considered. The lens protection unit 230 is made of an elastic material such as silicone resin, and is provided in the vicinity of the objective lens 22 for BD. As shown in FIGS. 13A and 13B, the lens protection unit 230 may be disposed on the outer peripheral side of the objective lenses 9 and 22 in some cases. In such a case, it is preferable to correct the horizontal movement amount in consideration of the position of the lens protection unit 230. For example, when the focus servo is lost while accessing the DVD using the DVD objective lens 9, the “protection amount” is used as the lens protection unit 230 from the radial position of the outermost peripheral portion of the DVD objective lens 9. Distances up to can be used.

  In step 205, focus on processing is executed. Considering the possibility that the focus servo is lost due to the influence of scratches and dust on the optical disc 100, the optical pickup 6 so that the objective lens 22 and the lens protection unit 230 are located on the inner peripheral side of the rim region 101. It may not be sufficient to move the horizon horizontally. That is, although the objective lens 22 and the lens protection unit 230 are located on the inner peripheral side with respect to the rim region 101, the light beam irradiation position may be included in a region where scratches or dust of the optical disc 100 exists. In such a case, the focus-on process may be performed after moving the optical pickup 6 in the inner or outer circumferential direction of the disk radial direction by a distance equal to or larger than the size of scratches and dust (for example, 5 mm). .

  Since the normal rim region 101 is located on the outermost periphery of the optical disc 100, if a switch for detecting that the optical pickup 6 has moved to the outermost periphery of the optical disc 100 is provided, the function of this switch is provided. It is possible to detect that the position of the optical pickup 6 has reached the rim region 101.

  As described above, in the present embodiment, when performing the focus-on process, if it is detected that the optical pickup 6 is in an area where there is a possibility of colliding with the rim 102, the position of the optical pickup 6 is set to the disc for avoiding the collision. Since the optical disk 100 is moved to the inner peripheral side, it is possible to prevent the optical disk 100 from being damaged or the objective lens from being damaged.

  The DVD objective lens 9 and the BD objective lens 22 are arranged in the radial direction of the optical disc 100. However, when the DVD objective lens 9 is located on the outer peripheral side of the BD objective lens 22, the BD When the objective lens 22 is used to access the vicinity of the outermost peripheral portion of the BD, the DVD objective lens 9 may face the rim region 101 in some cases. However, since the DVD objective lens 9 has a long focal length and is set at a position away from the optical disc 100, the risk of colliding with the rim region 102 during the focus-on operation is low.

(Embodiment 3)
Next, a third embodiment of the optical disc apparatus of the present invention will be described with reference to FIG. The optical disk apparatus of this embodiment also has the configuration shown in FIG.

  Here, when data is being reproduced from the optical disc 100 (during reproduction), or when an operation of moving the light beam irradiation position from the inner circumference side of the disc to the outer circumference side is being performed (during seek operation), out of focus occurs. Suppose that

  In step 501, it is determined in which operation mode “out of focus” or “during seek operation (Seek)” occurs. If it is during reproduction, the process proceeds to step 507, and if it is during a seek operation, the process proceeds to step 502. When the focus is lost during the seek operation, the cause may be due to the occurrence of an overrun in which the irradiation position of the light beam exceeds the end of the optical disc 100 or not. This difference corresponds to whether or not the optical disc 100 is present at the irradiation position of the light beam.

  In step 502, it is determined whether or not the optical disc 100 is present at the light beam irradiation position. If the optical disk 100 does not exist at the light beam irradiation position, it is determined that an overrun has occurred, and the process proceeds to step 503. In step 503, first, the objective lens is moved away from the optical disc apparatus 1. Specifically, the objective lenses 9 and 22 are retracted in the direction away from the optical disc 100 by the lens actuator.

  After there is no possibility that the optical pickup 6 collides with the rim region 101 of the optical disc 100 by the lens movement described above, the optical pickup is moved to the inner peripheral side of the optical disc 100 in step 504. At this time, the position of the optical pickup 6 can be determined based on the output of the position detector 12. When the transfer table 11 is operated by a stepping motor, the position of the optical pickup 6 can be determined by counting the driving pulses of the stepping motor. When the transfer table 11 is operated by a DC motor, the position of the optical pickup 6 can be determined by counting drive pulses of a linear encoder or the like. Note that, as in the second embodiment, when a portion that easily collides with the rim region 101 is located on the outer peripheral side of the objective lens that is actually used, the inner peripheral side is the distance to which the “correction amount” is added. It is preferable to move the optical pickup 6 to the position.

  In this way, even if the objective lenses 9 and 22 approach the optical disk 100, the optical pickup 6 is moved horizontally (traverse) to a position where the optical pickup 6 does not collide with the rim region 101 of the optical disk 100. Start processing. When the focus-on process is started, the objective information layers 9 and 22 are brought close to the optical disc 100 in order to obtain a target information layer (focus search). When the focus search brings the focal point of the light beam close to the target information layer and the focus pull-in is completed (servo control on), tracking control is started in step 506. Thereafter, the seek operation is retried for the target track.

  If it is determined in step 501 above that the focus has been lost during "playback", or if it is determined in step 502 that "in seek operation" but no overrun has occurred, step Proceeding to step 507, the objective lenses 9 and 22 are moved away from the optical disc 100.

  In step 508, it is determined whether or not the optical pickup 6 is located in the rim region 101 and a region facing the vicinity thereof. The position of the optical pickup 6 can be determined based on the output of the position detector 12.

  When the optical pickup 6 is located in the rim region 101 and the region facing the rim region 101, the optical pickup 6 is placed on the optical disc 100 so that the optical pickup 6 does not collide with the rim region 101 of the optical disc 100 during the next focus-on process. Move to the inner circumference side (step 509). On the other hand, when it is determined in step 508 that the optical pickup is not located in the rim region or the region facing the rim region, the process proceeds to step 505 as it is. For the detection range of the rim area, a margin determined by the feed resolution of the transfer table 11 may be added to the radial size (width) of the actual rim area 101 on the optical disc 100.

  According to the optical disk device of the present embodiment, when the focus servo is restarted by performing an appropriate process depending on whether the “reproduction” or “seek” operation was performed when the focus was lost. In addition, it is possible to avoid the optical pickup 6 from colliding with the optical disc 100.

  Since the DVD objective lens 9 in each embodiment has a longer focal length than the BD objective lens 22, as shown in FIG. 12, the DVD objective lens 9 is farther from the optical disc 100 than the BD objective lens 22 is. Although arranged in position, these objective lenses 9 and 22 are moved together by an actuator 240. Therefore, as described above, even when data is recorded / reproduced with respect to the DVD using the objective lens 9, the working distance is limited by the objective lens 22 or the lens protection unit 230 on the BD side, and the objective lens 22 or the lens protection unit 230 may collide with the protruding portion 102 of the optical disc 100. Therefore, when the optical pickup includes both the DVD objective lens 9 and the BD objective lens 22, it is effective to perform the rim avoidance process according to the present invention even when the operation is performed on the DVD optical disk. It is.

(Embodiment 4)
Next, a fourth embodiment of the optical disc apparatus according to the present invention will be described with reference to FIG. FIG. 14 shows the configuration of the optical disc apparatus of the present embodiment. In the optical disk apparatus of FIG. 14, the same components as those of FIG.

  The optical disk apparatus according to the present embodiment is different from the optical disk apparatus according to the above-described embodiment in that the 80 mm adapter detection unit 31 is provided.

  The 80 mm adapter detection unit 31 determines whether the optical disk 100 loaded with the optical disk device is a “80 mm diameter disk with an 80 mm adapter mounted” or a “120 mm diameter disk”.

  Next, the determination procedure by the 80 mm adapter detection unit 31 will be described with reference to FIG. The operation for this determination is preferably performed when the activation process of the optical disc 100 is performed.

  Whether the diameter of the optical disc 100 is 80 mm or 120 mm is described in the disc information area on the optical disc 100. Such disc information is recorded in the management area of the optical disc 100. When the optical disc 100 is, for example, a BD, the disc information is recorded in the “PIC area”.

  Whether the diameter of the optical disk 100 is 80 mm or 120 mm can be determined by measuring the elapsed time until the disk motor 2 reaches a certain number of rotations, and determining the size. When the same voltage is applied to the disk motor 2, the time required for the optical disk 100 to reach a predetermined rotational speed is proportional to the inertia value (a constant multiple of the fourth power of the disk radius). For this reason, the ratio of the time required for the 120 mm diameter disk and the 80 mm diameter disk to reach the predetermined rotational speed is 81:16. Actually, there is inertia of the disk motor 2, and the ratio is, for example, 90:25. For this reason, if the time until the rotational speed of the disk with a diameter of 120 mm reaches a predetermined value (for example, 1000 rpm) is 9.0 seconds, the time until the rotational speed of the disk with a diameter of 80 mm reaches a predetermined value is 2.5 seconds. Become. Therefore, the time until the rotational speed of the optical disc 100 reaches a predetermined value is compared with a reference value (for example, 5.0 seconds). If the time is shorter than the reference value, the optical disc 100 can be determined to be a disc with a diameter of 80 mm.

  Hereinafter, the operation of the present embodiment will be described with reference to FIG.

  First, in step 601, the disk motor 2 is rotated. In step 602, the time until the rotational speed of the disk motor 2 reaches a predetermined value (for example, 1000 rpm) is measured. In step 603, it is determined whether or not the time until the rotational speed of the disk motor 2 acquired in step 602 reaches a predetermined value is 5.0 seconds or less. If it is 5.0 seconds or less, it is determined that the optical disk 100 is an 80 mm disk without an 80 mm disk adapter. If it exceeds 5.0 seconds, the process proceeds to step 604.

  In step 604, disc information recorded on the optical disc 100 is acquired. In step 605, it is determined whether the disc is a 120 mm disc or an 80 mm disc based on the disc information acquired in step 604. If the disc information indicates “80 mm disc”, the optical disc 100 is determined to be an 80 mm diameter disc with an 80 mm disc adapter set. On the other hand, when the disc information indicates “120 mm disc”, the optical disc 100 can be determined as a 120 mm diameter disc.

  According to this embodiment, the 80 mm adapter can be detected by the 80 mm adapter detection unit 31. In the present embodiment, when an 80 mm adapter is detected, the optical pickup 6 is retracted so as to bypass the protrusion 152 of the adapter 150 shown in FIG. Specifically, the position and range of the rim region 101 in each of the above-described embodiments are replaced with the position and range of the rim region 101 of a disk having a diameter of 80 mm, and the retraction amount is a value that takes into account the protrusion amount of the 80 mm adapter (for example, 0 .9 mm). Note that the retraction amount when avoiding the protruding portion of the 80 mm adapter is larger than the retraction amount necessary to avoid the rim 102 of the optical disk 100 having a diameter of 120 mm.

  The retraction amount when the 80 mm adapter is not detected can be set to the same degree (for example, 0.5 mm) as the retraction amount in the case of the 120 mm diameter optical disc based on the protrusion amount of the rim 102 in the 80 mm disc. In this case, the amount of retraction can be reduced compared to the case where there is an 80 mm adapter, so that the time required for the focus-on process can be shortened.

  In this embodiment, the presence / absence of an 80 mm adapter is detected. However, when it is found that an 80 mm diameter disk is set, a detour operation taking into account the protruding amount of the adapter is performed regardless of the presence or absence of the adapter. You may make it carry out uniformly. This makes it possible to omit the configuration and processing for adapter detection.

  The optical disc apparatus according to the present invention can avoid a part of the optical pickup from colliding with the optical disc when performing the focus-on process after the focus servo is released, and the reliability is improved.

(A) is a figure which shows a mode that the space | interval of the optical disk 100 and the objective lens 22 becomes small gradually, (b) is a figure which shows the waveform of a focus error (FE) signal, (c) is. FIG. 5 is a waveform diagram showing the amplitude of a reproduction signal (RE). It is a figure which shows the structure of DVD-RAM prescribed | regulated to Standard ECMA-330. (A) to (c) are diagrams showing how an overrun occurs during a seek operation in a conventional optical disc apparatus. (A) And (b) is a figure which shows a mode that the overrun generate | occur | produced during the seek operation | movement, when the 80 mm diameter disk with an adapter is set to the conventional optical disk apparatus. (A) to (c) are diagrams showing a state in which defocusing occurs in the vicinity of a rim region of an optical disc in a conventional optical disc apparatus. (A) And (b) is a figure which shows a mode that the overrun generate | occur | produced during seek operation | movement in the optical disk apparatus of this invention. (A) to (c) are diagrams showing a state in which defocusing occurs in the vicinity of the rim region of the optical disc in the optical disc apparatus of the present invention. It is a block diagram which shows the structure of embodiment of the optical disk device by this invention. It is a flowchart which shows the operation | movement process procedure in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement process procedure in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement process procedure in the 3rd Embodiment of this invention. It is a figure which shows the arrangement | positioning relationship between the objective lens 9 for DVD, and the objective lens 22 for BD. FIG. 3 is a diagram showing an arrangement relationship between a DVD objective lens 9, a BD objective lens 22, and an optical disc 100. It is a block diagram which shows the structure of embodiment of the optical disk apparatus in the 4th Embodiment of this invention. It is a flowchart which shows the procedure of 80 mm adapter detection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Disc motor 3 Rotation control part 4 Rotation number detection part 5 Controller 6 Optical pick-up 7 Red semiconductor laser 8 Light beam (red)
9 Objective lens (red)
DESCRIPTION OF SYMBOLS 10 Red laser drive part 11 Transfer stand 13 Transfer control part 14 Focus control part 15 Tracking control part 16 Optical detection part 17 Preamplifier 18 Reproduction signal processing part 19 Seek control part 21 Light beam (blue)
22 Objective lens (blue)
23 Blue semiconductor laser 24 Blue laser drive unit 30 Rim detection unit 31 80 mm adapter detection unit 40 Control unit 100 Optical disk 101 Rim region 102 Projection unit 150 Adapter 230 Lens protection unit

Claims (12)

Light having a light source that emits a light beam for irradiating an optical disc, at least one objective lens that focuses the light beam, and an actuator that can move the objective lens in a direction perpendicular to the optical disc With a pickup,
Transfer means for moving the optical pickup in the radial direction of the optical disc;
For the seek operation, when the optical pickup is moved from the inner circumference side of the optical disk to the outer circumference side by the transfer means, the detection means for detecting that the irradiation position of the light beam has passed the end of the optical disk;
When it is detected that the irradiation position of the light beam has passed the end of the optical disc, the actuator retracts the objective lens away from the optical disc by the actuator, and the optical pickup is moved to the optical disc by the transfer means. An optical disc apparatus comprising control means for moving the inner peripheral side.   When it is detected that the irradiation position of the light beam has passed the end of the optical disc, the control means moves the objective lens in a direction away from the optical disc. 2. The optical disc apparatus according to claim 1, wherein the optical pickup is retracted in a direction away from the optical disc by a distance longer than a distance corresponding to a height.   The optical disk apparatus according to claim 2, wherein the control means performs a focus-on process after moving the optical pickup to an inner peripheral side with respect to a protruding portion of the optical disk.   The optical disk apparatus according to claim 1, wherein the control unit changes a distance for retracting the objective lens in a direction away from the optical disk in accordance with a diameter of the optical disk.   2. The optical disc apparatus according to claim 1, wherein when the optical disc has a diameter of 80 mm, a distance for retracting the optical pickup in a direction away from the optical disc is set to be larger than a protruding amount of the protruding portion of the adapter.   The optical disc apparatus according to claim 1, wherein the detection unit is capable of detecting whether or not the objective lens is located in a region facing a protruding portion of the optical disc.   If the objective lens is located in a region facing the protruding portion of the optical disk when the focus servo is removed during a recording or reproducing operation, the control means retracts the objective lens in a direction away from the optical disk by the actuator. The optical disc apparatus according to claim 6, wherein the optical pickup is moved to an inner peripheral side of the protrusion.   8. The optical disc apparatus according to claim 7, wherein the control means performs a focus-on process after moving the optical pickup to the inner peripheral side.   The at least one objective lens includes a first objective lens that exhibits a first numerical aperture and a second objective lens that exhibits a second numerical aperture higher than the first numerical aperture. Optical disk device.   The optical disk apparatus according to claim 9, wherein the second numerical aperture is 0.8 or more. A method of driving an optical disc apparatus including an optical pickup having an objective lens for focusing a light beam on the optical disc,
For the seek operation, the step of moving the optical pickup from the inner periphery side of the optical disc to the outer periphery side;
If the irradiation position of the light beam exceeds the end of the optical disc during the seek operation, the objective lens is moved away from the optical disc, and the optical pickup is moved to the inner peripheral side of the optical disc. Step to
A method for driving an optical disc device including:   When it is detected that the irradiation position of the light beam has passed the end of the optical disc, the objective lens in the optical pickup is moved away from the optical disc by an actuator in the optical pickup, and the optical pickup is moved to the optical disc. A control device for an optical disk device, which is moved to the inner peripheral side of the optical disk device.

Images