JP2005108366A - Actuator,optical pickup device and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the thickness reduction and the miniaturization of an actuator while maintaining driving accuracy of an objective lens. <P>SOLUTION: In this actuator, driving means which drive a lens holder are arranged across the lens holder as to a tracking direction. As a result, since space is formed at least at one side of the tangential direction of the lens holder, the space is set to the optical path of a light beam LB which is made incident to the objective lens. Thus, the thinning of a device is attained as compared with the case where configuration of the device in which the light beam is made incident to the objective from the bottom of a lens holding member like the conventional practice, is adopted. Moreover, since line springs (elastic members) which support the lens holder 81 are provided at parts where driving means are provided in the conventional device, that is, at the side of the tangential direction of the holder, increase of a width to the tracking direction of the actuator is suppressed as much as possible. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an actuator, an optical pickup device, and an optical disc device, and more specifically, an actuator for driving an objective lens of an optical pickup device, a recording surface of an optical disc is irradiated with a light beam, and reflected light from the recording surface is emitted. The present invention relates to an optical pickup device that receives light and an optical disk device including the optical pickup device.

  In recent years, with the rapid progress of digital technology and the improvement of performance of information devices such as personal computers (hereinafter referred to as “PCs”) and video devices, the amount of information (data amount) handled by information devices has increased rapidly. Yes. For this reason, optical discs such as CDs (Compact Discs) and DVDs (Digital Versatile Discs) capable of recording data equivalent to about 7 times the CDs on discs having the same diameter as CDs have been attracting attention as information recording media. Along with the lowering of the price, an optical disk device as a drive device for accessing the optical disk has come into wide use.

  In an optical disc apparatus, information is recorded and erased by irradiating a laser beam onto a recording surface of an optical disc on which spiral or concentric tracks are formed, and information is reproduced based on reflected light from the recording surface. Yes. The optical disc apparatus includes an optical pickup device as a device for irradiating a recording surface of the optical disc with laser light to form a light spot and receiving reflected light from the recording surface.

  Usually, the optical pickup device includes an objective lens, and guides the light beam emitted from the light source to the recording surface of the optical disc and guides the return light beam reflected by the recording surface to a predetermined light receiving position, which is disposed at the light receiving position. The detected optical detector and the objective lens are in the optical axis direction (hereinafter also referred to as “focus direction”) and in the direction orthogonal to the track tangential direction (diameter direction of the optical disk orthogonal to the optical axis of the objective lens) (hereinafter “ A lens driving device (actuator) for driving in the tracking direction). From the photodetector, a signal including not only reproduction information of data recorded on the recording surface but also information (servo information) necessary for position control of the objective lens is output.

  In the optical disc apparatus, the focus error signal and the track error signal are detected based on the signal including the servo information from the photodetector, and when the light spot has a defocus, the objective lens is connected via the lens driving device. Is shifted in the focus direction to correct focus shift (focus control). When there is a track shift in the light spot, the objective lens is shifted in the tracking direction via the lens driving device to correct the track shift (tracking control).

  Recently, personal computers have been drastically reduced in size and weight, and so-called notebook computers that can be easily carried and sub-notebook computers smaller than that (hereinafter collectively referred to as "notebook computers") are commercially available. It became so. In addition, notebook personal computers with built-in optical disk devices (including removable cases) are becoming mainstream. And the thickness of notebook computers has become one of the important specifications (specifications), and it has come to influence sales.

  Therefore, various objective lens driving devices corresponding to thinning have been devised (see, for example, Patent Documents 1 to 4). However, in the objective lens driving devices disclosed in Patent Documents 1 to 4, the external dimensions are large, and there is a possibility that further downsizing of the notebook personal computer may be difficult.

Japanese Patent Application Laid-Open No. 11-167736 JP-A-11-175992 JP 2000-155966 A JP 2002-133688 A

  The present invention has been made under such circumstances, and a first object of the invention is to provide an actuator that can be reduced in thickness and size while maintaining the driving accuracy of the objective lens.

  A second object of the present invention is to provide an optical pickup device that can be reduced in thickness and size while maintaining the position control accuracy of the objective lens.

  A third object of the present invention is to provide an optical disc apparatus that can be reduced in thickness and size while maintaining access accuracy to the optical disc.

  The invention according to claim 1 is an actuator for driving an objective lens for condensing light on a recording surface of an optical disc, the base; a lens holding for holding the objective lens between the base and the optical disc A first drive unit and a second drive unit respectively disposed on one side and the other side of the lens holding member with respect to a first direction that is a diameter direction of the optical disc perpendicular to the optical axis of the objective lens; Driving means for driving the lens holding member in at least two directions of the optical axis direction and the first direction; only between the first driving portion and the second driving portion with respect to the first direction; One end of the lens holding member is connected to the lens holding member and extends in a second direction orthogonal to the optical axis direction and the first direction. The lens holding member is supported in a non-contact manner with respect to the base. An actuator comprising; support mechanism and the.

  According to this, the objective lens is held between the base and the optical disk by the lens holding member, and the driving means for driving the lens holding member in at least two directions of the optical axis direction and the first direction is an objective. With respect to a first direction which is a diameter direction of the optical disc perpendicular to the optical axis of the lens, the first and second drive units are disposed on one side and the other side of the lens holding member, respectively. Therefore, since a space is formed on at least one side of the lens holding member in the second direction orthogonal to the optical axis direction and the first direction, the space can be set as an optical path of light incident on the objective lens. it can. As a result, it is possible to reduce the thickness of the device as compared with the case where a device configuration in which light enters from the lower side of the lens holding member (opposite side of the optical disk in the optical axis direction) as in the past. It becomes. Further, the support mechanism for supporting the lens holding member in a non-contact manner with respect to the base is only connected between the first driving unit and the second driving unit in the first direction, and one end thereof is connected to the lens holding member. And a plurality of elastic members extending in the second direction. Therefore, since the support mechanism is arranged at the portion where the driving means is provided in the conventional apparatus, it is possible to suppress the increase in the width of the actuator in the first direction as much as possible. That is, it is possible to reduce the thickness and size of the actuator while maintaining the driving accuracy of the objective lens.

  In this case, as in the actuator according to claim 2, the support mechanism can be provided on each of the one side and the other side of the lens holding member in the second direction.

  In the actuator according to claim 2, as in the actuator according to claim 3, the driving means further includes at least a rotation direction with the second direction as an axis and a rotation direction with the first direction as an axis. On the other hand, the lens holding member can be rotated.

  In each of the actuators according to claims 1 to 3, as in the actuator according to claim 4, the drive means includes a magnetic circuit and a coil, and includes a plurality of elastic members constituting the support mechanism. A drive signal may be supplied to the coil via each.

  In each of the actuators according to claims 1 to 4, as in the actuator according to claim 5, each of the plurality of elastic members is disposed in a predetermined plane perpendicular to the optical axis of the objective lens. can do.

  In this case, as in the actuator according to claim 6, the position of the predetermined surface in the optical axis direction is set in the vicinity of the position of the principal point of the objective lens in the optical axis direction. Can do.

  In each of the actuators according to claims 1 to 4, as in the actuator according to claim 7, the plurality of elastic members are arranged closer to the optical disc side closer to the optical axis of the objective lens. The actuator according to any one of claims 1 to 4.

  In each of the actuators according to claims 1 to 7, as in the actuator according to claim 8, the plurality of elastic members are such that a distance between adjacent elastic members in the first direction is equal to an optical axis of the objective lens. It can be assumed that it is arranged so as to become wider as it approaches.

  The invention according to claim 9 is an optical pickup device that irradiates a recording surface of an optical disc with laser light and receives reflected light from the recording surface, and a light source that emits the laser light; An optical system that includes an objective lens that focuses the laser beam to be recorded on the recording surface, and that guides the returned light beam reflected by the recording surface to a predetermined light receiving position; and drives the objective lens An optical pickup device comprising: the actuator according to claim 1; and a photodetector arranged at the light receiving position.

  According to this, since the actuator according to any one of claims 1 to 8 in which there is almost no increase in outer dimensions and the thickness is reduced, while maintaining the position control accuracy of the objective lens, As a whole, the optical pickup device can be reduced in thickness and size.

A tenth aspect of the present invention is an optical disc apparatus that performs at least reproduction among information recording, reproduction, and erasure with respect to the optical disc, and the optical pickup device according to the ninth aspect;
And a processing device that controls the actuator based on an output signal of the pickup device and performs at least one of recording, reproduction, and erasing of the information using the output signal of the optical pickup device. is there.

  According to this, since the thin optical pickup device according to claim 9 in which an increase in the outer dimension is suppressed is provided, the entire optical disc device is reduced in thickness and size while maintaining the access accuracy to the optical disc. Can be achieved.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an optical disc apparatus according to an embodiment of the present invention.

  The optical disk apparatus 20 shown in FIG. 1 includes a spindle motor 22, an optical pickup apparatus 23, a laser control circuit 24, an encoder 25, a motor driver 27, a reproduction signal processing circuit 28, a servo controller 33, and the like. A buffer RAM 34, a buffer manager 37, an interface 38, a flash memory 39, a CPU 40 as a processing device, a RAM 41, a tilt sensor 42, and the like are provided. In addition, the connection line in FIG. 1 shows the flow of a typical signal and information, and does not represent all the connection relationships of each block. In the present embodiment, as an example, an information recording medium compliant with the DVD standard is used as the optical disc 15.

  The optical pickup device 23 is a device for irradiating the recording surface of the optical disk 15 on which spiral or concentric tracks are formed with laser light and receiving reflected light from the recording surface. The configuration of the optical pickup device 23 will be described later.

  The tilt sensor 42 outputs a signal including information on the tilt of the optical disc 15 with respect to an objective lens of the optical pickup device 23 described later. Here, information relating to the tangential direction of the track (the direction perpendicular to the tracking direction and the optical axis of the objective lens 60) (hereinafter also referred to as “tangential direction”) (hereinafter also referred to as “tangential tilt”), and A signal including information related to a tilt (hereinafter also referred to as “radial tilt”) in a direction orthogonal to the tangential direction of the track (coincident with the tracking direction) (hereinafter also referred to as “radial direction”) is output.

  As shown in FIG. 2, the reproduction signal processing circuit 28 includes two I / V amplifiers (28a, 28f), a servo signal detection circuit 28b, a wobble signal detection circuit 28c, an RF signal detection circuit 28d, a decoder 28e, and It is composed of a tilt detection circuit 28g and the like.

  The I / V amplifier 28a converts a current signal, which is an output signal of the optical pickup device 23, into a voltage signal and amplifies it with a predetermined gain. The servo signal detection circuit 28b detects a servo signal (such as a focus error signal and a track error signal) based on the output signal of the I / V amplifier 28a. The servo signal detected here is output to the servo controller 33. The wobble signal detection circuit 28c detects a wobble signal based on the output signal of the I / V amplifier 28a. The RF signal detection circuit 28d detects an RF signal based on the output signal of the I / V amplifier 28a. The decoder 28e extracts address information and synchronization information from the wobble signal detected by the wobble signal detection circuit 28c. The address information extracted here is output to the CPU 40, and the synchronization information is output to the encoder 25. The decoder 28e performs a decoding process and an error detection process on the RF signal detected by the RF signal detection circuit 28d. When an error is detected, the decoder 28e performs an error correction process. The data is stored in the buffer RAM 34. The RF signal includes address information, and the address information extracted from the RF signal is output to the CPU 40.

  The I / V amplifier 28f converts a current signal, which is an output signal of the tilt sensor 42, into a voltage signal and amplifies it with a predetermined gain. The tilt detection circuit 28g detects information related to tangential tilt and radial tilt based on the output signal of the I / V amplifier 28g. Information on the detected tangential tilt is output to the servo controller 33 as a tangential tilt information signal. Further, information regarding the radial tilt is output to the servo controller 33 as a radial tilt information signal.

  Returning to FIG. 1, the servo controller 33 generates various control signals for controlling the optical pickup device 23 based on various signals from the reproduction signal processing circuit 28, and outputs them to the motor driver 27. The configuration of the servo controller 33 will be described in detail later.

  The motor driver 27 outputs a drive signal to the optical pickup device 23 based on a control signal from the servo controller 33. The motor driver 27 outputs a drive signal to the spindle motor 22 based on an instruction from the CPU 40.

  The buffer RAM 34 is a buffer area for temporarily storing data to be recorded on the optical disk 15 (recording data) and data reproduced from the optical disk 15 (reproduction data), and a variable area for storing various program variables. And have.

  The buffer manager 37 manages data input / output to / from the buffer RAM 34. Then, the CPU 40 is notified when the amount of data stored in the buffer area reaches a predetermined amount.

  The encoder 25 takes out the recording data stored in the buffer RAM 34 based on an instruction from the CPU 40 via the buffer manager 37, modulates the data, adds an error correction code, and the like, and outputs a write signal to the optical disc 15. Generate. The write signal generated here is output to the laser control circuit 24.

  The laser control circuit 24 controls the output of the laser light applied to the optical disc 15 based on a write signal from the encoder 25 and an instruction from the CPU 40.

  The interface 38 is a bidirectional communication interface with a host (for example, a personal computer), and is compliant with the ATAPI (AT Attachment Packet Interface) standard as an example.

  The flash memory 39 includes a program area and a data area, and a program written in a code readable by the CPU 40 is stored in the program area. The data area stores information related to the seek operation of the optical pickup device 23 (hereinafter abbreviated as “seek information”), recording conditions, and the like.

  The CPU 40 controls the operation of each unit in accordance with a program stored in the program area of the flash memory 39, and stores data necessary for the control in the variable area of the buffer RAM 34 and the RAM 41.

  Here, the configuration and the like of the optical pickup device 23 will be described with reference to FIGS. 3 to 8 as an example.

  The optical pickup device 23 shown in FIG. 3 irradiates the recording surface of the optical disk 15 rotated by the spindle motor 22 with laser light and receives reflected light from the recording surface, and the pickup body 101. Two seek rails 102 that guide the movement of the pickup body 101 in the X-axis direction (left and right direction on the paper surface), a seek motor (not shown) for driving the pickup body 101 in the X-axis direction, and the like It is comprised including. Here, the tracking direction and the radial direction are the X-axis direction, the tangential direction is the Y-axis direction, and the focus direction is the Z-axis direction.

  The pickup main body 101 is disposed on the housing 71, the light flux emitting system 12 that emits a light flux having a wavelength of 660 nm toward the recording surface of the optical disk 15, and the light flux from the light flux emitting system 12. And a condensing system 11 that condenses light at a predetermined position on the recording surface.

  As shown in FIG. 4 as an example, the light beam emission system 12 includes a light source unit 51 as a light source, a collimating lens 52, a beam splitter 54, a detection lens 58, a cylindrical lens 57, a light receiver 59 as a light detector, and the like. I have.

  The light source unit 51 includes a semiconductor laser (not shown) as a light source that emits a light beam having a wavelength of 660 nm. The light source unit 51 is fixed to the housing 71 such that the maximum intensity emission direction of a light beam emitted from the light source unit 51 (hereinafter also referred to as “emitted light beam”) is the −Y direction.

  The collimating lens 52 is disposed on the −Y side of the light source unit 51 and makes the emitted light beam substantially parallel light. The beam splitter 54 is disposed on the −Y side of the collimating lens 52, transmits the outgoing light beam that has been made substantially parallel light by the collimating lens 52, and transmits the light beam (returned light beam) reflected by the recording surface of the optical disk 15. Branch in the -X direction. The outgoing light beam transmitted through the beam splitter 54 enters the light collecting system 11.

  The detection lens 58 is disposed on the −X side of the beam splitter 54 and condenses the return light beam branched in the −X direction by the beam splitter 54. The cylindrical lens 57 is disposed on the −X side of the detection lens 58 and shapes the return light beam collected by the detection lens 58. The light receiver 59 is disposed on the −X side of the cylindrical lens 57 and receives the return light beam shaped by the cylindrical lens 57 at its light receiving surface. This light receiver 59 uses a four-divided light receiving element in which the light receiving area is divided into four as in the case of a normal optical disk apparatus, and a signal corresponding to the amount of received light is reproduced from each light receiving area. It is output to the processing circuit 28.

The condensing system 11 includes an objective lens 60, a lens holder 81 as a lens holding member, and a rising mirror 83, as shown in FIGS. four tracking coils _{(82a 1, 82a 2, 82b} 1, 82b 2), 4 single focusing coil _{(84a 1, 84a 2, 84b} 1, 84b 2), 4 single radial tilt coils (88a _1, 88a ₂ , 88 b ₁ , 88 b ₂ ), four permanent magnets (91 a ₁ , 91 a ₂ , 91 b ₁ , 91 b ₂ ), a base plate 85 as a base, two stems (87 a, 87 b), and eight conductive materials A wire spring (92a ₁ , 92a ₂ , 92a ₃ , 92a ₄ , 92b ₁ , 92b ₂ , 92b ₃ , 92b ₄ ) and two elastic substrates (93a, 93b) are formed.

The base plate 85 is a member having a bottom wall and two side walls (+ Y side and −Y side) rising in the + Z direction from the bottom wall. The bottom wall is fixed at a predetermined position on the housing 71. In the following, the side wall on the + Y side is referred to as a first side wall 85e, and the side wall on the −Y side is referred to as a second side wall 85f. The first side wall 85e is formed with an opening for preventing interference with the _four wire springs (92a ₁ , 92a ₂ , 92a ₃ , 92a ₄ ) and transmitting the emitted light beam from the light beam emitting system 12. ing. Further, cutout portions in order to prevent interference with the four wire spring _{(92b 1, 92b 2, 92b} 3, 92b 4) are formed in the second side wall 85f. Note that four prismatic projections 85a to 85d are formed on the upper surface of the base plate 85, and these projections 85a to 85d serve as yokes for forming a magnetic circuit.

The permanent magnets 91a ₁ , 91b ₁ , 91a ₂ , 91b ₂ are block-shaped permanent magnets having substantially the same magnetic characteristics. The permanent magnet 91a ₁ and the permanent magnet 91a ₂ are respectively attached to the −Y side surface of the first side wall 85e. Here, the permanent magnet 91a ₁ is disposed at the + X side end portion of the −Y side surface of the first side wall 85e, and the permanent magnet 91a ₂ is disposed at the −X end portion. The permanent magnet 91b ₁ and the permanent magnet 91b ₂ are respectively attached to the + Y side surface of the second side wall 85f. Here, the permanent magnet 91b ₁ is disposed at the + X side end of the + Y side surface of the second side wall 85f, and the permanent magnet 91b ₂ is disposed at the −X end. That is, the −Y side surface of the permanent magnet 91a ₁ and the + Y side surface of the permanent magnet 91b ₁ face each other in the Y-axis direction. Further, the −Y side surface of the permanent magnet 91a ₂ and the + Y side surface of the permanent magnet 91b ₂ are opposed to each other in the Y-axis direction.

  The stems 87a and 87b are block-like members, respectively, and are fixed at predetermined positions on the housing 71 (see FIG. 3). The stem 87a is disposed on the + Y side of the first side wall 85e, and the stem 87b is disposed on the −Y side of the second side wall 85f. Each stem is formed with a through hole extending in the Y-axis direction.

  A part of the elastic substrate 93a is fixed to the surface on the + Y side of the stem 87a, and includes a plurality of input terminals and output terminals. A part of the elastic substrate 93b is fixed to the surface on the −Y side of the stem 87b, and includes a plurality of input terminals and output terminals. A signal line from the motor driver 27 is connected to each input terminal. Each elastic substrate can be slightly elastically deformed in the Y-axis direction in order to absorb vibration in the Y-axis direction.

  The lens holder 81 is a member whose outer shape is similar to a cube, and is disposed at substantially the center of the stem 87a and the stem 87b in the Y-axis direction. Further, as shown in FIG. 7, a through-hole extending in the Z-axis direction is formed in the central portion of the lens holder 81 as an optical path of the emitted light beam from the light beam emitting system 12. At the end of the through hole on the + Z side, the objective lens 60 is disposed so that the optical axis thereof substantially coincides with the central axis of the through hole. Furthermore, as shown in FIG. 6, the tracking coil, the focus coils, and the radial tilt coils are integrated with the lens holder 81 in a predetermined positional relationship. Since the objective lens 60, the lens holder 81, and each coil move and rotate as a unit, a unit in which these units are integrated will be referred to as a “movable part” for convenience.

The eight wire springs (92a ₁ , 92a ₂ , 92a ₃ , 92a ₄ , 92b ₁ , 92b ₂ , 92b ₃ , 92b ₄ ) have substantially the same spring characteristics. Each wire spring is located on a predetermined XY plane (arranged in the same plane) with its longitudinal direction substantially coincident with the Y-axis direction. Of the four wire springs (92a ₁ , 92a ₂ , 92a ₃ , 92a ₄ ), one end of each is embedded in the + Y side surface of the lens holder 81 (hereinafter also referred to as “+ Y side surface” for convenience). The other end is connected to a predetermined output terminal of the elastic substrate 93a by soldering or the like through the opening formed in the first side wall 85e of the base plate 85 and the through hole formed in the stem 87a. Yes. The other four wire springs (92b ₁ , 92b ₂ , 92b ₃ , 92b ₄ ) have one ends on the surface on the −Y side of the lens holder 81 (hereinafter also referred to as “−Y side surface” for convenience). The other end is embedded in the predetermined output terminal of the elastic substrate 93b by soldering or the like through the notch formed in the second side wall 85f of the base plate 85 and the through hole formed in the stem 87b. It is connected. That is, the movable part is elastically supported by each stem via the eight wire springs. The through-holes formed in the stems 87a and 87b are filled with a viscoelastic material such as silicon gel, for example, so that a damping effect of vibration generated in each wire spring is achieved.

  In the present embodiment, as shown in FIG. 7, the support center of the movable part by each line spring is set so as to substantially coincide with the center of inertia of the movable part and the principal point O of the objective lens 60.

Here, a wire spring 92a ₁ is disposed on the + X side end of the + Y side surface of the lens holder 81, and a wire spring 92a ₂ is disposed on the −X side thereof. In addition, a wire spring 92a ₄ is disposed at the −X side end of the + Y side surface of the lens holder 81, and a wire spring 92a ₃ is disposed on the + X side thereof. As can be seen from FIG. 8 schematically showing the positional relationship among the wire springs 92a _{1 to} 92a ₄ , the emitted light beam LB, and the objective lens 60, the distance (d ₁₎ between the wire springs 92a ₁ and 92a _{2 in} the X-axis direction. Is substantially equal to the distance between the wire spring 92a ₃ and the wire spring 92a _{4 in} the X-axis direction, and is smaller than the distance between the wire spring 92a ₂ and the wire spring 92a _{3 in} the X-axis direction (referred to as d ₂ ). Is arranged. As a result, as shown in FIGS. 7 and 8, the optical path of the emitted light beam LB from the light beam emitting system 12 can be brought closer to the objective lens 60 in the Z-axis direction. It is possible to reduce the thickness.

The focusing coils are coils having substantially the same shape, and are connected so that substantially the same drive current is supplied to each. In the present embodiment, each focus coil is used not only for focus control but also for tangential tilt control. Therefore, as an example, a focus control drive current (hereinafter referred to as “focus control drive current”) is provided via the line spring 92a ₁ and the line spring 92b ₁ . For convenience, it is also referred to as “focus drive current”), and a drive current for tangential tilt control (hereinafter also referred to as “tangential tilt drive current” for convenience) via the wire springs 92a ₂ and 92b _2. Shall be supplied. Each focusing coil has a size and a shape corresponding to a required driving force.

The focusing coil 84a ₁ and the focusing coil 84b ₁ are fixed to the + X side surface of the lens holder 81, respectively. The focusing coil 84a ₁ is disposed at a position facing the permanent magnet 91a ₁ , and the focusing coil 84b ₁ is disposed at a position facing the permanent magnet 91b ₁ .

The focusing coil 84a ₂ and the focusing coil 84b ₂ are fixed to the −X side surface of the lens holder 81, respectively. The focusing coil 84a ₂ is disposed at a position facing the permanent magnet 91a ₂ , and the focusing coil 84b ₂ is disposed at a position facing the permanent magnet 91b ₂ .

Here, the case where the focus driving current through the wire springs 92a ₁ and wire spring 92b ₁ is supplied to each focusing coil. When the focus drive current is supplied, a force (referred to as force Ff) is generated in the + Z direction (or −Z direction) based on the current flowing through the focus coil 84a ₁ and the magnetic flux from the permanent magnet 91a ₁ . A force is generated in the same direction as the force Ff based on the current flowing through the focusing coil 84a ₂ and the magnetic flux from the permanent magnet 91a ₂ . Further, a force is generated in the same direction as the force Ff on the basis of the magnetic flux from the current and the permanent magnet 91b ₁ through the focusing coil 84b _1, and the flux from the current and the permanent magnet 91b ₂ through the focusing coil 84b ₂ Is generated in the same direction as the force Ff. Here, since the respective forces are set to have substantially the same magnitude, the movable portion is slightly driven in the + Z direction (or −Z direction) in accordance with the magnitude of the focus drive current. The drive direction (+ Z direction or −Z direction) can be controlled by the direction of the focus drive current.

Next, a case where a tangential tilt drive current is supplied to each focusing coil via the wire spring 92a ₂ and the wire spring 92b ₂ will be described. When the tangential tilt driving current is supplied, a force (Ftan) is generated in the + Z direction (or −Z direction) based on the current flowing through the focusing coil 84a ₁ and the magnetic flux from the permanent magnet 91a _1. , a force is generated in the same direction as the force Ftan based on the magnetic flux from the current and the permanent magnets 91a ₂ through the focusing coil 84a _2. Further, a force is generated in the force Ftan opposite direction based on the magnetic flux from the current and the permanent magnet 91b ₁ through the focusing coil 84b _1, and the flux from the current and the permanent magnet 91b ₂ through the focusing coil 84b ₂ The force is generated in the direction opposite to the force Ftan. Here, since each force is set to have the same magnitude, the movable portion rotates around the rotation axis in the X-axis direction passing through the support center in accordance with the magnitude of the tangential tilt drive current. It will be. The rotation direction (clockwise or counterclockwise) can be controlled by the direction of the tangential tilt drive current.

Each of the tracking coils is a coil having substantially the same shape, and is connected so that substantially the same drive current is supplied thereto. In the present embodiment, as an example, it is assumed that a driving current for tracking control (hereinafter also referred to as “tracking driving current” for convenience) is supplied via the wire spring 92a ₃ and the wire spring 92b ₃ . Each tracking coil has a size and a shape corresponding to the required driving force.

The tracking coil 82a ₁ is attached to the focusing coil 84a ₁ so as to face the permanent magnet 91a ₁ . The tracking coil 82a ₂ is attached to the focusing coil 84a ₂ so as to face the permanent magnet 91a ₂ . The tracking coil 82a ₃ is attached to the focusing coil 84a ₃ so as to face the permanent magnet 91a ₃ . The tracking coil 82a ₄ is attached to the focusing coil 84a ₄ so as to face the permanent magnet 91a ₄ .

When a tracking drive current is supplied to each tracking coil via the wire spring 92a ₃ and the wire spring 92b ₃ , the + X direction is based on the current flowing through the tracking coil 82a ₁ and the magnetic flux from the permanent magnet 91a _1. (or -X direction) (a Ftr) force is generated, a force is generated in the same direction as the force Ftr based on the magnetic flux from the current and the permanent magnets 91a ₂ through the tracking coils 82a _2. Further, a force is generated in the same direction as the force Ftr based on the magnetic flux from the current and the permanent magnet 91b ₁ through the tracking coils 82b _1, and the flux from the current and the permanent magnet 91b ₂ through the tracking coil 82b ₂ Is generated in the same direction as the force Ftr. Here, since the respective forces are set to have substantially the same magnitude, the movable portion is slightly driven in the + X direction (or -X direction) according to the magnitude of the tracking drive current. The driving direction (+ X direction or −X direction) can be controlled by the direction of the tracking driving current.

The radial tilt coils are coils having substantially the same shape, and are connected so that substantially the same drive current is supplied thereto. In this embodiment, as an example, it is assumed that a drive current for radial tilt control (hereinafter also referred to as “radial tilt drive current” for convenience) is supplied via the wire spring 92a ₄ and the wire spring 92b ₄ . Further, each radial tilt coil has a size and a shape corresponding to a required driving force.

The radial tilt coil 88a ₁ is disposed inside the focusing coil 84a ₁ , and the radial tilt coil 88a ₂ is disposed inside the focusing coil 84a ₂ . Further, the radial tilt coil 88b ₁ is disposed inside the focusing coil 84b ₁ , and the radial tilt coil 88b ₂ is disposed inside the focusing coil 84b ₂ . Each radial tilt coil (88a ₁ , 88a ₂ , 88b ₁ , 88b ₂ ) is disposed so as to surround the protrusions 85a to 85d of the base plate 85 described above.

When the radial tilt driving current through the wire springs 92a ₄ and wire spring 92b ₄ are supplied to the respective radial tilt coils, based on the magnetic flux from the current and the permanent magnets 91a ₁ through the radial tilt coils 88a ₁ force Te + Z direction (or the -Z direction) (the FRAD) is generated, a force in the direction opposite to the force FRAD based on the magnetic flux from the current and the permanent magnets 91a ₂ through the radial tilt coils 88a ₂ occurs To do. Further, a force is generated in the same direction as the force Frad based on the magnetic flux from the current and the permanent magnet 91b ₁ through the radial tilt coils 88b _1, from the current and the permanent magnet 91b ₂ through the radial tilt coil 88b ₂ A force is generated in the direction opposite to the force Frad based on the magnetic flux. Here, since each force is set to have the same magnitude, the movable part rotates around the rotation axis in the Y-axis direction passing through the support center in accordance with the magnitude of the radial tilt drive current. It becomes. The rotation direction (clockwise or counterclockwise) can be controlled by the direction of the radial tilt drive current.

  Next, the configuration and the like of the servo controller 33 will be described with reference to FIG. As shown in FIG. 9, the servo controller 33 includes a focus control signal generation circuit 33a, a tracking control signal generation circuit 33b, a tangential tilt control signal generation circuit 33c, a radial tilt control signal generation circuit 33d, a power amplifier 33e, and the like. It is configured to include.

  The focus control signal generation circuit 33a generates a focus control signal Sfc for correcting a focus shift based on the focus error signal from the reproduction signal processing circuit 28. The tracking control signal generation circuit 33b generates a tracking control signal Str for correcting the track deviation based on the track error signal from the reproduction signal processing circuit 28. The tangential tilt control signal generation circuit 33 c generates a tangential tilt control signal Stan for correcting the tangential tilt based on the tangential tilt information signal from the reproduction signal processing circuit 28. The radial tilt control signal generation circuit 33d generates a radial tilt control signal Srad for correcting the radial tilt based on the radial tilt information signal from the reproduction signal processing circuit 28. The power amplifier 33e amplifies the control signal generated by each control signal generation circuit and outputs it to the motor driver 27.

  Here, the operation of the optical pickup device 23 configured as described above will be described.

  The light beam emitted from the light source unit 51 in the −Y direction becomes substantially parallel light by the collimator lens 52 and then enters the beam splitter 54. The light beam that has passed through the beam splitter 54 enters the light collecting system 11. The light beam incident on the condensing system 11 is reflected in the + Z direction by the rising mirror 83, enters the objective lens 60 through the through hole of the lens holder 81, and is formed as a minute spot on the recording surface of the optical disk 15 by the objective lens 60. Focused.

  The reflected light reflected by the recording surface of the optical disk 15 is made into a substantially parallel light again by the objective lens 60 as a return light beam and enters the rising mirror 83. The return light beam incident on the rising mirror 83 is reflected in the + Y direction and enters the beam splitter 54. The returned light beam branched in the −X direction by the beam splitter 54 is received by the light receiver 59 through the detection lens 58 and the cylindrical lens 57. The light receiver 59 performs photoelectric conversion for each light receiving region, and the photoelectric conversion signals are output to the reproduction signal processing circuit 28, respectively.

  Here, control of the position and orientation of the objective lens 60 in the optical disc apparatus 20 will be described.

<Focus control>
1. The reproduction signal processing circuit 28 converts the output signal of the light receiver 59 into a voltage signal by the I / V amplifier 28 a, detects the focus error signal by the servo signal detection circuit 28 b, and outputs it to the servo controller 33.
2. The servo controller 33 generates a focus control signal based on the focus error signal in the focus control signal generation circuit 33a, amplifies it with the power amplifier 33e, and outputs it to the motor driver 27.
3. The motor driver 27 outputs a focus drive current corresponding to the focus control signal to the optical pickup device 23.
4). In the optical pickup device 23, the focus drive current from the motor driver 27 is input to a predetermined input terminal of each elastic substrate, and the focus coils (84a ₁ , 84a) are connected via the wire springs 92a ₁ and 92b _{1. 2} , 84b ₁ , 84b ₂ ).
5). When a focus drive current flows through each focus coil, a drive force corresponding to the magnitude and direction of the current is generated, thereby driving the movable portion in the focus direction. As a result, the objective lens 60 is shifted in the focus direction, and the focus shift is corrected.

<Tracking control>
1. The reproduction signal processing circuit 28 converts the output signal of the light receiver 59 into a voltage signal by the I / V amplifier 28 a, detects the track error signal by the servo signal detection circuit 28 b, and outputs it to the servo controller 33.
2. The servo controller 33 generates a tracking control signal based on the track error signal in the tracking control signal generation circuit 33b, amplifies it by the power amplifier 33e, and outputs it to the motor driver 27.
3. The motor driver 27 outputs a tracking drive current corresponding to the tracking control signal to the optical pickup device 23.
4). In the optical pickup device 23, the tracking drive current from the motor driver 27 is input to a predetermined input terminal of each elastic substrate, and each tracking coil (82a ₁ , 82a is passed through the wire spring 92a ₃ and the wire spring 92b _{3. 2} , 82 b ₁ , 82 b ₂ ).
5). When a tracking driving current flows through each tracking coil, a driving force corresponding to the magnitude and direction of the current is generated, thereby driving the movable portion in the tracking direction. As a result, the objective lens 60 is shifted in the tracking direction, and the track deviation is corrected.

《Tangential tilt control》
1. The reproduction signal processing circuit 28 converts the output signal of the tilt sensor 42 into a voltage signal by the I / V amplifier 28f, detects information related to the tangential tilt by the tilt detection circuit 28g, and outputs the tangential tilt information signal as the servo controller 33. Output to.
2. The servo controller 33 generates a tangential tilt control signal based on the tangential tilt information signal in the tangential tilt control signal generation circuit 33 c, amplifies it by the power amplifier 33 e, and outputs it to the motor driver 27.
3. The motor driver 27 outputs a tangential tilt driving current corresponding to the tangential tilt control signal to the optical pickup device 23.
4). In the optical pickup device 23, the tangential tilt driving current from the motor driver 27 is input to a predetermined input terminal of each elastic substrate, and each focusing coil (84a _{1) is} passed through the wire spring 92a ₂ and the wire spring 92b _2. , 84a ₂ , 84b ₁ , 84b ₂ ).
5). When a driving current for tangential tilt flows through each focusing coil, a driving force is generated according to the magnitude and direction of the current, and the movable part rotates about the X axis rotation axis passing through the support center. To do. As a result, the objective lens 60 rotates around the rotation axis in the X-axis direction passing through the principal point, and the tangential tilt is corrected. Here, since the principal point of the objective lens 60 is on the rotation axis, no cross action occurs.

《Radial tilt control》
1. The reproduction signal processing circuit 28 converts the output signal of the tilt sensor 42 into a voltage signal by the I / V amplifier 28f, detects information related to the radial tilt by the tilt detection circuit 28g, and outputs the information to the servo controller 33 as a radial tilt information signal. To do.
2. The servo controller 33 generates a radial tilt control signal based on the radial tilt information signal by the radial tilt control signal generation circuit 33d, amplifies it by the power amplifier 33e, and outputs it to the motor driver 27.
3. The motor driver 27 outputs a radial tilt drive current corresponding to the radial tilt control signal to the optical pickup device 23.
4). In the optical pickup device 23, the radial tilt drive current from the motor driver 27 is input to a predetermined input terminal of each elastic substrate, and each radial tilt coil (88a _{1) is} passed through the wire spring 92a ₄ and the wire spring 92b _4. , 88a ₂ , 88b ₁ , 88b ₂ ).
5). When a radial tilt driving current flows through each radial tilt coil, a driving force corresponding to the magnitude and direction of the current is generated, and the movable part rotates around the rotation axis in the Y-axis direction passing through the support center. To do. As a result, the objective lens 60 rotates around the rotation axis in the Y-axis direction passing through the principal point, and the radial tilt is corrected. Here, since the principal point of the objective lens 60 is on the rotation axis, no cross action occurs.

<Recording process>
Next, processing (recording processing) in the optical disc apparatus 20 when a recording request command from the host is received will be briefly described with reference to FIG. The flowchart of FIG. 10 corresponds to a series of processing algorithms executed by the CPU 40. When a recording request command is received from the host, the start address of the program corresponding to the flowchart of FIG. Starts.

  In the first step 501, a control signal for controlling the rotation of the spindle motor 22 based on the recording speed is output to the motor driver 27, and the reproduction signal processing circuit 28 is notified that a recording request command has been received from the host. . Further, the buffer manager 37 is instructed to store the data (recording data) received from the host in the buffer RAM 34.

  In the next step 503, when it is confirmed that the optical disk 15 is rotating at a predetermined linear velocity, servo-on is set for the servo controller 33. As a result, focus control, tracking control, tangential tilt control, and radial tilt control are performed as described above. Note that focus control, tracking control, tangential tilt control, and radial tilt control are performed as needed until the recording process is completed.

  In the next step 505, OPC (Optimum Power Control) is performed based on the recording speed to obtain the optimum recording power. That is, while changing the recording power stepwise, predetermined data is trial-written in a trial writing area called PCA (Power Calibration Area), and then the data is sequentially reproduced. For example, the asymmetry detected from the RF signal When the value almost coincides with a target value obtained in advance through experiments or the like, it is determined that the recording quality is the highest, and the recording power at that time is set as the optimum recording power.

  In the next step 507, the current address is obtained based on the address information from the decoder 28e.

  In the next step 509, a difference (address difference) between the current address and the target address extracted from the recording request command is calculated.

  In the next step 511, it is determined whether seek is necessary based on the address difference. Here, the threshold stored in the flash memory 39 is referred to as one of the seek information, and if the address difference exceeds the threshold, the determination here is affirmed and the routine proceeds to step 513.

  In step 513, a seek motor control signal corresponding to the address difference is output to the motor driver 27. As a result, the seek motor is driven to perform a seek operation. Then, the process returns to step 507.

  If the address difference does not exceed the threshold value in step 511, the determination in step 511 is denied and the process proceeds to step 515.

  In step 515, it is determined whether or not the current address matches the target address. If the current address does not match the target address, the determination here is denied and the routine proceeds to step 517.

  In this step 517, the current address is acquired based on the address information from the decoder 28e. Then, the process returns to step 515.

  Thereafter, the processing from step 515 to step 517 is repeated until the determination at step 515 is affirmed.

  If the current address matches the target address, the determination at step 515 is affirmed, and the routine proceeds to step 519.

  In step 519, the encoder 25 is allowed to write. As a result, the recording data is written to the optical disk 15 via the encoder 25, the laser control circuit 24, and the optical pickup device 23. When all the recording data is written, a predetermined end process is performed, and then the recording process is ended.

《Reproduction processing》
Further, processing (reproduction processing) in the optical disc apparatus 20 when a reproduction request command is received from the host will be described with reference to FIG. The flowchart of FIG. 11 corresponds to a series of processing algorithms executed by the CPU 40. When a reproduction request command is received from the host, the start address of the program corresponding to the flowchart of FIG. Starts.

  In the first step 701, a control signal for controlling the rotation of the spindle motor 22 based on the reproduction speed is output to the motor driver 27, and the reproduction signal processing circuit 28 is notified that a reproduction request command has been received from the host. .

  In the next step 703, when it is confirmed that the optical disk 15 is rotating at a predetermined linear velocity, servo-on is set for the servo controller 33. As a result, focus control, tracking control, tangential tilt control, and radial tilt control are performed as described above. Note that focus control, tracking control, tangential tilt control, and radial tilt control are performed as needed until the reproduction process is completed.

  In the next step 705, the current address is acquired based on the address information from the decoder 28e.

  In the next step 707, a difference (address difference) between the current address and the target address extracted from the reproduction request command is calculated.

  In the next step 709, it is determined whether or not seeking is necessary in the same manner as in step 511. If a seek is necessary, the determination here is affirmed and the routine proceeds to step 711.

  In step 711, a seek motor control signal corresponding to the address difference is output to the motor driver 27. Then, the process returns to step 705.

  On the other hand, if no seek is necessary in step 709, the determination in step 709 is denied and the process proceeds to step 713.

  In this step 713, it is determined whether or not the current address matches the target address. If the current address does not match the target address, the determination here is denied and the routine proceeds to step 715.

  In this step 715, the current address is acquired based on the address information from the decoder 28e. Then, the process returns to step 713.

  Thereafter, the processing from step 713 to 715 is repeated until the determination in step 713 is affirmed.

  If the current address matches the target address, the determination at step 713 is affirmed, and the routine proceeds to step 717.

  In step 717, the reproduction signal processing circuit 28 is instructed to read. Thus, the reproduction data is acquired by the reproduction signal processing circuit 28 and stored in the buffer RAM 34. This reproduced data is transferred to the host via the buffer manager 37 and the interface 38 in units of sectors. When the reproduction of the data designated by the host is completed, a predetermined termination process is performed and the reproduction process is terminated.

As is clear from the above description, in the optical disk apparatus according to the present embodiment, the four tracking coils (82a ₁ , 82a ₂ , 82b ₁ , 82b ₂ ) and the four focus coils (84a ₁ , 84a ₂ , 84b). ₁ , 84b ₂ ), four radial tilt coils (88a ₁ , 88a ₂ , 88b ₁ , 88b ₂ ) and four permanent magnets (91a ₁ , 91a ₂ , 91b ₁ , 91b ₂ ) constitute drive means. ing. Further, an actuator is constituted by the drive means, each wire spring, the lens holder 81, and the stems 87a and 87b.

  Further, the processing device is realized by the CPU 40 and a program executed by the CPU 40. However, it goes without saying that the present invention is not limited to this. That is, the above embodiment is merely an example, and at least a part of the processing device realized by the processing according to the program by the CPU 40 may be configured by hardware, or all may be configured by hardware. good.

The wire springs 92a _{1 to} 92a ₄ , 92b _{1 to} 92b ₄ and the stems 87a and 87b constitute a support mechanism.

As described above in detail, according to the actuator according to the present embodiment, the plurality of wire springs (92a _{1 to} 92a ₄ ) extend in the tangential direction, and one end thereof is connected to the first side wall 85e of the base plate 85. The other end is connected to the lens holder 81, the plurality of wire springs (92b _{1 to} 92b ₄ ) extend in the tangential direction, one end is connected to the second side wall 85f of the base plate 85, and the other The end is connected to the lens holder 81. Further, driving means (82a ₁ , 82a ₂ , 82b ₁ , 82b ₂ , 84a ₁ , 84a ₂ , 84b ₁ , 84b ₂ ) for driving the lens holding member 81 at least in the optical axis direction (focus direction) and the tracking direction of the objective lens. , 88a ₁ , 88a ₂ , 88b ₁ , 88b ₂ , 91a ₁ , 91a ₂ , 91b ₁ , 91b ₂ ) are arranged with the lens holder 81 in between in the tracking direction. Accordingly, it is possible to secure a space as an optical path of light incident on the objective lens 60 on the tangential direction side of the lens holder 81, and thus an apparatus configuration in which light is incident from the tangential direction of the lens holder 81. Can be adopted. By doing so, it is possible to reduce the thickness of the device as compared with the conventional case where a device configuration in which light enters from below the lens holder 81 is employed. Further, by connecting the wire springs (92a _{1 to} 92a ₄ ) to the portion where the driving means is provided in the conventional apparatus, that is, the surface on the tangential direction side of the reticle holder 81, the width in the tracking direction of the actuator can be increased. It is possible to suppress the increase as much as possible. That is, according to the actuator according to the present embodiment, it is possible to reduce the thickness and size of the actuator while maintaining the driving accuracy of the objective lens.

  In the actuator according to the present embodiment, a current as a drive signal is supplied to each of the coils constituting the drive means via each of the wire springs that hold the lens holder 81. Accordingly, since it is not necessary to connect the external power source and the coil with different wirings, the apparatus can be simplified, and the deterioration of the position control accuracy of the lens holder due to dragging of the wirings can be avoided. be able to.

  Further, since all of the plurality of wire springs are arranged in the same plane, the movability of the lens holder in the tangential tilt direction can be improved.

  Further, since the plane on which the plurality of wire springs are arranged is located in the vicinity of the principal point O of the objective lens 60 with respect to the optical axis direction of the objective lens 60, the principal point of the objective lens 60 is set near the rotation axis. The occurrence of cross action can be suppressed as much as possible.

  In addition, since the plurality of line springs are arranged such that the distance between the line springs adjacent to each other in the tracking direction becomes larger as the distance from the optical axis of the objective lens becomes closer, the laser beam is made closer to the objective lens 60. Is possible.

  In addition, according to the optical pickup device and the optical disk device of the present embodiment, since the actuator of the present invention is provided, the overall thickness can be reduced with little increase in outer dimensions.

  In addition, according to the present embodiment, since the optical pickup device itself and the position of the objective lens can be controlled with high accuracy, at least reproduction of information recording, reproduction and erasure on the optical disk is included. Access can be performed accurately and stably.

In the above embodiment, as shown in FIG. 12 as an example, leaf springs 192a _{1 to} 192b ₄ may be employed instead of the wire springs 92a _{1 to} 92b ₄ . In this case, a plurality of leaf springs in which the width and the interval between the leaf springs are reproduced as designed values can be created by penetrating a single plate in a lattice shape. That is, by forming the plate spring and the lens holder 81 formed of a resin material in this way by integral molding, the plate spring can be assembled to the lens holder 81 as designed. Therefore, by adopting such a configuration, it is possible to reduce the cross action that has occurred due to the assembly error.

In this case, as shown in FIG. 13A and FIG. 13B which is an enlarged view of the leaf spring 192a ₁ , a bent portion 191 may be provided in the middle of each leaf spring. By doing so, as shown in FIG. 13C, the rigidity of the leaf spring in the longitudinal direction (Y-axis direction) can be reduced, so that a decrease in sensitivity when the frequency of the control signal is low is suppressed. can do. Note that the bent portion 191 is not limited to the shape in FIG. 13B, and various shapes can be employed.

In the present embodiment, a case has been described in which the wire spring 92a ₁ ~92b ₄ is disposed in the same plane, the present invention is not limited to such an arrangement, for example, as shown in FIG. 14, a wire spring 92a ₁ and wire spring 92a ₂ , wire spring 92a ₃ and wire spring 92a ₄ (and wire spring 92b ₁ and wire spring 92b ₂ , wire spring 92b ₃ and wire spring 92b ₄ ) have the same position in the X-axis direction. Further, it may be arranged at a predetermined interval in the Z-axis direction.

Furthermore, as shown in FIG. 15A as an example, from the configuration of FIG. 14, the wire spring 92 a ₁ is arranged in the + X direction with respect to the wire spring 92 a ₂ , and the wire spring 92 a ₄ is less than the wire spring 92 a _3. A configuration arranged in the X direction may be adopted.

  The left figure of FIG. 15 (B) is the schematic diagram which looked at the state which employ | adopted arrangement | positioning of the wire spring of FIG. 15 (A) from + X direction, and the right figure of FIG. 15 (B) is the above-mentioned FIG. It is the schematic diagram which looked at the state which employ | adopted arrangement | positioning of a wire spring from the + Y direction. As can be seen from these drawings, by arranging the wire spring as shown in FIG. 15A, the interference between the wire spring and the incident light beam LB does not occur, and the Z-axis direction between the incident light beam LB and the objective lens 60 can be obtained. Therefore, the size of the condensing system 11 in the Z-axis direction can be reduced as compared with the case where the arrangement of FIG. 14 is adopted.

Of course, even when the leaf springs 192a _{1 to} 192b ₄ are employed, the same arrangement as that shown in FIGS. 14 and 15A can be employed.

  Further, in the above embodiment, when the tangential tilt is small, the tangential tilt control may not be performed. In this case, only the radial tilt information signal is generated in the tilt detection circuit 28g. In the servo controller 33, the tangential tilt control signal generation circuit 33c may be omitted.

  In the above embodiment, for example, an optical element including an electro-optic crystal or a liquid crystal exhibiting an electro-optic effect and imparting an optical phase difference to the light beam is disposed on the optical path between the light source unit 51 and the objective lens. In order to cancel the wavefront aberration caused by the tangential tilt, the motor driver 27 applies a driving voltage to the optical element that gives the optical phase difference according to the tangential tilt control signal. .

In the above embodiment, for example, an optical element including an electro-optic crystal or a liquid crystal exhibiting an electro-optic effect and imparting an optical phase difference to the light beam is disposed on the optical path between the light source unit 51 and the objective lens. In order to cancel the wavefront aberration caused by the radial tilt, the motor driver 27 applies a driving voltage to the optical element that gives the optical phase difference in accordance with the radial tilt control signal. That is, the radial tilt coils may not be provided. In this case, as shown in FIG. 16 as an example, the movable part may be held by _four wire springs 92 _{1 to} 924.

  In the above embodiment, the case where the tilt sensor is arranged separately from the optical pickup device has been described. However, the present invention is not limited to this, and the tilt sensor may be mounted in the optical pickup device.

  In the above embodiment, the power amplifier 33 e in the servo controller 33 may be provided in the motor driver 27.

  In the embodiment described above, the elastic substrates 93a and 93b that can be slightly elastically deformed in the Y-axis direction in order to absorb the vibration in the Y-axis direction are used as the substrate. In the case where the influence of axial vibration is small, a normal substrate may be used.

  In the above embodiment, the optical disk apparatus capable of recording and reproducing information has been described as the optical disk apparatus. However, the present invention is not limited to this, and the optical disk apparatus capable of reproducing at least information among recording, reproducing, and erasing of information. If it is good.

  In the above embodiment, the optical disk apparatus corresponding to the optical disk conforming to the DVD system standard has been described as the optical disk apparatus. However, the present invention is not limited to this, and for example, a laser beam having a wavelength of about 405 nm or about 780 nm. An optical disc apparatus corresponding to an optical disc using a laser beam having a wavelength may be used.

  Further, in the above-described embodiment, the case where a single semiconductor laser is provided as the optical disk device has been described. However, the present invention is not limited thereto, and for example, an optical disk device including a plurality of semiconductor lasers that emit light beams having different wavelengths may be used. good. In this case, for example, at least one of a semiconductor laser that emits a light beam with a wavelength of about 405 nm, a semiconductor laser that emits a light beam with a wavelength of about 660 nm, and a semiconductor laser that emits a light beam with a wavelength of about 780 nm may be included. . That is, the optical disk apparatus may be an optical disk apparatus that supports a plurality of types of optical disks that conform to different standards.

  In the above embodiment, the case where the interface 38 conforms to the ATAPI standard has been described. However, the present invention is not limited to this. For example, ATA (AT Attachment), SCSI (Small Computer System Interface), USB (Universal Serial Bus) 1 , USB 2.0, IEEE 1394, IEEE 802.3, serial ATA, and serial ATAPI.

1 is a block diagram showing a configuration of an optical disc device according to an embodiment of the present invention. FIG. 2 is a block diagram for explaining a configuration of a reproduction signal processing circuit in FIG. 1. It is a figure for demonstrating the structure of the optical pick-up apparatus in FIG. It is a figure for demonstrating the detailed structure of the light beam emission system in FIG. It is a perspective view of the condensing system in FIG. It is a figure for demonstrating the detailed structure of the condensing system in FIG. It is the sectional view on the AA line of FIG. It is a figure for demonstrating arrangement | positioning of a wire spring. It is a block diagram for demonstrating the structure of the servo controller in FIG. It is a flowchart for demonstrating the recording process in the optical disk device performed according to the recording request command from a host. 10 is a flowchart for explaining a reproduction process in the optical disc apparatus performed in response to a reproduction request command from a host. It is a perspective view of a condensing system using a leaf spring. 13A is a perspective view of a condensing system in which a bent portion is provided in the leaf spring, and FIG. 13B is an enlarged view of the bent portion of the leaf spring, and FIG. These are figures for demonstrating the effect | action of a bending part. It is FIG. (1) for demonstrating the other example of arrangement | positioning of a wire spring. FIG. 15A is a diagram (part 2) for explaining another arrangement example of the wire spring, and FIG. 15B is an operation when the wire spring arrangement of FIG. 15A is adopted. It is a figure for demonstrating. It is a perspective view of the condensing system corresponding to biaxial control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Light-beam emission system (optical system), 15 ... Optical disk, 20 ... Optical disk apparatus, 23 ... Optical pick-up apparatus, 40 ... CPU (processing apparatus), 51 ... Light source unit (light source), 59 ... Light receiver (light detector) , 60 ... objective lens, 81 ... lens holder (lens holding member), 82a ₁ , 82a ₂ , 82b ₁ , 82b ₂ ... tracking coil (a part of driving means), 84a ₁ , 84a ₂ , 84b ₁ , 84b ₂ ... Coil for focusing (part of driving means), 85 ... Base plate (base), 88a ₁ , 88a ₂ , 88b ₁ , 88b ₂ ... Coil for radial tilt (part of driving means), 91a ₁ , 91a ₂ , 91b ₁ , 91b ₂ ... Permanent magnet (part of driving means), 92a _{1 to} 92a ₄ , 92b _{1 to} 92b ₄ ... Wire spring (elastic member).

Claims (10)

An actuator that drives an objective lens that focuses light on a recording surface of an optical disc,
With the base;
A lens holding member for holding the objective lens between the base and the optical disc;
A first driving unit and a second driving unit disposed on one side and the other side of the lens holding member with respect to a first direction which is a diameter direction of the optical disc perpendicular to the optical axis of the objective lens, and the lens Drive means for driving the holding member in at least two directions of the optical axis direction and the first direction;
With respect to the first direction, only one end of the lens holding member is connected between the first driving unit and the second driving unit, and the second direction is orthogonal to the optical axis direction and the first direction. An actuator having a plurality of extending elastic members and supporting the lens holding member in a non-contact manner with respect to the base.   The actuator according to claim 1, wherein the support mechanism is provided on each of one side and the other side of the lens holding member in the second direction.   The said drive means further rotates the said lens holding member in at least one of the rotation direction centering on the said 2nd direction, and the rotation direction centering on the said 1st direction. Actuator. The driving means includes a magnetic circuit and a coil,
The actuator according to any one of claims 1 to 3, wherein a drive signal is supplied to the coil via each of a plurality of elastic members constituting the support mechanism.   The actuator according to claim 1, wherein each of the plurality of elastic members is disposed in a predetermined plane orthogonal to the optical axis of the objective lens.   6. The actuator according to claim 5, wherein a position of the predetermined surface in the optical axis direction is set in the vicinity of a position of the principal point of the objective lens in the optical axis direction.   5. The actuator according to claim 1, wherein the plurality of elastic members are arranged closer to the optical disc as being closer to the optical axis of the objective lens.   The plurality of elastic members are arranged such that the distance between the elastic members adjacent to each other in the first direction increases as the distance from the optical axis of the objective lens decreases. The actuator according to claim 1. An optical pickup device that irradiates a recording surface of an optical disc with laser light and receives reflected light from the recording surface,
A light source that emits the laser light;
An optical system that includes an objective lens that condenses the laser light emitted from the light source on the recording surface, and guides the return light beam reflected by the recording surface to a predetermined light receiving position;
The actuator according to any one of claims 1 to 8, which drives the objective lens;
An optical pickup device comprising: a photodetector disposed at the light receiving position. An optical disc apparatus that performs at least reproduction of information recording, reproduction, and erasure on an optical disc,
An optical pickup device according to claim 9;
An optical disk apparatus comprising: a processing device that controls the actuator based on an output signal of the pickup device and performs at least reproduction of recording, reproduction, and erasure of the information using an output signal of the optical pickup device.

Images