JP4228514B2 - Optical head device and optical recording / reproducing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical recording / reproducing apparatus such as an optical disk recording / reproducing apparatus and a magneto-optical disk recording / reproducing apparatus, an optical recording / reproducing apparatus, and an optical head used in the optical recording / reproducing apparatus.
[0002]
[Prior art]
FIG. 12 is a block diagram of a magneto-optical recording / reproducing apparatus as a first conventional example of an optical recording / reproducing apparatus.
A magneto-optical recording / reproducing apparatus 100 illustrated in FIG. 12 includes a magneto-optical disk (MO) 110 such as a mini disk (MD), a magneto-optical pickup 120 as an optical pickup of the first prior art, and a control processing unit. 130.
[0003]
The magneto-optical pickup 120 includes a substrate 121, a spindle motor 122, a biaxial actuator 123, an optical unit 124, a screw and screw feed mechanism 126, and a feed motor 127.
A spindle motor 122, a screw and screw feed mechanism 126, and a feed motor 127 are mounted on the substrate 121.
The overwrite magnetic head 125, the biaxial actuator 123, and the optical unit 124 are moved in parallel with the surface of the magneto-optical disk 110 by a screw and screw feed mechanism 126 as a whole.
[0004]
When the magneto-optical disk 110 is introduced in the direction of the arrow and the center hole 112 of the magneto-optical disk 110 is fitted into the spindle motor 122, the spindle motor 122 rotates the magneto-optical disk 110.
The control device 130 positions the tip of the magneto-optical pickup 120 on which the overwrite magnetic head 125 is mounted at a predetermined position (address) on the magneto-optical disk 110.
[0005]
The biaxial actuator 123 performs tracking control by a servo unit 134 described later.
A screw and screw feed mechanism 126 and a feed motor 127 that rotationally drives the screw and screw feed mechanism 126 perform tracking control of the biaxial actuator 123 in response to a control command of the servo unit 134.
[0006]
The optical unit 124 includes a laser diode (LD), a beam splitter, an objective lens, a photo detector, and the like. When parallel light is used, a collimator lens that collimates the light emitted from the laser diode (LD) is provided in the optical unit 124.
[0007]
In the magneto-optical pickup 120, an optical unit 124, a biaxial actuator 123, and an overwrite magnetic head 125 are integrally configured. In this specification, such a configuration is integrated feed-type optical pickup or MD. This is called a type optical pickup.
[0008]
The control processing unit 130 includes a head driving unit 131, a laser driving unit 132, a photodetector (PD) detection signal processing unit 133, a servo unit 134, a pre-demodulation processing unit 135, a demodulation unit 136, and a system controller 137. A modulation unit 138, a memory controller 139, and a RAM 140.
[0009]
An outline of the operation of the magneto-optical recording / reproducing apparatus 100 illustrated in FIG. 12 will be described.
The spindle motor 122 rotates the magneto-optical disk 110 loaded on the spindle motor at a predetermined rotational speed.
The beam light emitted from the laser diode in the optical unit 124 passes through the beam splitter and is further converged by the objective lens to focus on the recording surface of the magneto-optical disk 110. The reflected light from the magneto-optical disk 110 enters the beam splitter through the objective lens, is deflected by the beam splitter, and enters the photodetector. The photo detector is, for example, a quadrant detector.
[0010]
The PD detection signal processing unit 133 receives the detection signal from the quadrant detector and calculates a tracking error signal, a focus error signal, an RF signal, and the like by a known method.
The calculated tracking error signal, focus error signal, and the like are input to the servo unit 134 and used for tracking control, focus control, and the like.
[0011]
The pre-demodulation processing unit 135 demodulates the address from the calculation result in the PD detection signal processing unit 133, and the demodulated address is input to the servo unit 134 and the system controller 137.
[0012]
When a data write request to the magneto-optical recording / reproducing apparatus 100 is issued from an external device such as a host computer via an interface (I / F), the system controller 137 causes the servo unit 134, the modulation unit 138, and the memory controller 139 to operate. Control. Details are described below.
[0013]
The system controller 137 positions (tracks) the magneto-optical pickup 120 at a specified address of the magneto-optical disk 110 via the servo unit 134, and the objective lens mounted on the magneto-optical pickup 120 is the magneto-optical disk 110. Focus control is performed so as to be positioned at a predetermined position.
In the on-track state and the on-focus state, the system controller 137 sends the write data recorded in the RAM 140 to the modulation unit 138 via the memory controller 139.
[0014]
The modulation unit 138 performs modulation processing (encoding processing) such as error correction processing, run length restriction (RLL) processing, NRZ or NRZI modulation on the input write data.
[0015]
The head drive unit 131 drives the overwrite magnetic head 125 based on the modulation result in the modulation unit 138, and the laser drive unit 132 drives the laser diode in the optical unit 124 based on the modulation result in the modulation unit 138 to generate a magneto-optical disk. Data is written to 110.
[0016]
When a data read request is issued to the magneto-optical recording / reproducing apparatus 100 from an external device via an interface (I / F), the system controller 137 includes a servo unit 134, a pre-demodulation processing unit 135, a demodulation unit 136, and a memory controller. 139 is controlled. Details are described below.
[0017]
The system controller 137 positions (tracking control) the magneto-optical pickup 120 at the address where data reading of the magneto-optical disk 110 is designated via the servo unit 134, and the objective lens mounted on the magneto-optical pickup 120 is magneto-optical. Focus control is performed so that the disk 110 is positioned at a predetermined position.
In the on-track state and the on-focus state, the system controller 137 records the data demodulated by the demodulator 136 in the RAM 140 via the memory controller 139.
[0018]
In the above read processing, the analog RF signal calculated by the photodetector detection signal processing unit 133 is converted to a digital signal by the pre-demodulation processing unit 135, is signal equalized, and is phase-synchronized (PLL) processed to generate a clock signal. Reproduction is performed, and decoding processing, for example, Viterbi decoding processing is performed using the reproduction clock.
Further, the demodulation unit 136 performs error correction processing (ECC) on the signal processed by the pre-demodulation processing unit 135, demodulation processing reverse to that of the modulation unit 138, and the like, and decodes original data before encoding.
The data demodulated by the demodulator 136 is temporarily stored in the RAM 140 via the memory controller 139. When the predetermined data is read, the memory controller 139 transfers the data recorded in the RAM 140 to the external device via the interface. Output to.
[0019]
FIG. 13 is a block diagram of an optical head as a second prior art.
The magneto-optical head 220 illustrated in FIG. 13 uses wind pressure resulting from the rotation of the magneto-optical disk 210 in order to overcome the difficulty of performing focus control using the electromagnetic actuator described above with reference to FIG. This is a “flying head type magneto-optical head” in which the head portion is lifted to secure a predetermined distance in the focus direction.
[0020]
A magneto-optical head 220 illustrated in FIG. 13 has an optical block 221 for writing data on a magneto-optical disk 210 such as an MD rotated by a spindle motor 205 or reading data from the magneto-optical disk 210. A single-axis actuator 222, a voice coil motor (VCM) 223, a galvano mirror 224, and an overwrite magnetic head 225 mounted on the single-axis actuator 222 are included.
[0021]
In the optical block 221, a laser diode (LD), a beam splitter photo detector, and the like are integrally configured. However, the objective lens is provided at the tip of the head near the overwrite magnetic head 225 and is separated from the optical block 221.
[0022]
The single-axis actuator 222 is moved in one direction by a voice coil motor (VCM) 223.
Tracking control of the magneto-optical pickup 220 is performed by the voice coil motor 223 and the galvanometer mirror 224.
Focus control is performed by a single-axis actuator 222.
The distance is maintained when the overwrite magnetic head 225 floats from the surface of the magneto-optical disk 210 by a predetermined gap due to the wind pressure accompanying the rotation of the magneto-optical disk 210.
[0023]
The light beam emitted from the laser diode (LD) in the optical block 221 passes through the beam splitter, is deflected by the galvanometer mirror 224, and is guided to the objective lens located at the tip of the head.
The objective lens converges the beam light and irradiates the recording surface of the magneto-optical disk 210.
The reflected light from the magneto-optical disk 210 passes through the objective lens toward the galvano mirror 224, and the return light deflected by the galvano mirror 224 is incident on the beam splitter, deflected by the beam splitter, and incident on the photodetector. The photo detector is, for example, a quadrant detector.
[0024]
In the magneto-optical pickup 220, the optical system of the optical block 221 and the objective lens are optically connected via a galvano mirror 224.
Thus, since only the objective lens including the uniaxial actuator, the 45-degree mirror, and the flying head are used as the movable part, there is an advantage that the movable part becomes small.
The problem of this magneto-optical pickup 220 will be described later.
[0025]
FIG. 14 is a block diagram of a magneto-optical head device as a third prior art.
The magneto-optical head device 320 illustrated in FIG. 14 is a flying head type magneto-optical head device proposed by TeraStor.
This magneto-optical head device writes data to and reads data from a magneto-optical disk 310 such as an MD rotated by a spindle motor (not shown).
Therefore, the magneto-optical head device 320 includes a swing arm 321, a flying head type magneto-optical head 322 attached to one end of the arm 321, an objective lens 327 mounted on the magneto-optical head 322, and magnetic field modulation. Tracking control by rotating a coil (not shown), a first mirror 323 provided on the top of the magneto-optical head 322, a second mirror 324 provided on the arm 321 and the arm 321 in the horizontal direction. A voice coil motor 325 and a light source module 326.
[0026]
The light source module 326 includes a laser diode (LD), a beam splitter, a photo detector, and the like. The photo detector is, for example, a quadrant detector.
[0027]
The objective lens 327 is mounted on the magneto-optical head 322 and is separated from the light source module 326.
[0028]
The second mirror 324 and the first mirror 323 guide the light beam from the laser diode in the light source module 326 to the objective lens 327 mounted on the magneto-optical head 322. That is, the light beam emitted from the laser diode (LD) in the light source module 326 passes through the beam splitter and is deflected by the second mirror 324 toward the first mirror 323. The first mirror 323 deflects incident light toward the objective lens 327. The objective lens 327 converges the incident light and irradiates the recording surface of the magneto-optical disk 310.
[0029]
The reflected light from the magneto-optical disk 310 passes through the objective lens 327 mounted on the magneto-optical head 322, passes through the second mirror 324 from the first mirror 323 through the reverse path to the above, and the light source module 326. Enter the beam splitter inside and reach the photo detector.
[0030]
Tracking control of the magneto-optical head 322 is performed by driving the voice coil motor 325 and swinging the arm 321 in the horizontal direction (a surface parallel to the surface of the magneto-optical disk) within a predetermined angle range. The magneto-optical head 322 floats from the surface of the magneto-optical disk 310 by a distance necessary for access by wind pressure accompanying the rotation of the magneto-optical disk 310, so that focus control is unnecessary.
[0031]
Since the first mirror 323 or the second mirror 324 is driven by a microactuator, there is an advantage that two-step tracking control of coarse movement and fine movement is facilitated together with the swing arm 321.
The problem of the third prior art will be described later.
[0032]
FIG. 15 is a block diagram of a magneto-optical head device as a fourth prior art.
The magneto-optical head device 420 illustrated in FIG. 15 is a flying head type magneto-optical head device proposed by QUINTA.
[0033]
The magneto-optical head device includes an arm 421, a gimbal 422 formed of a flexible elastic member fixed to the tip of the arm 421, and a fixed distance from the magneto-optical disk 410 fixed to the tip of the gimbal 422. Slider 423, objective lens 424 mounted on slider 423, electrostatic mirror 425, optical system 426 disposed between electrostatic mirror 425 and objective lens 424, optical block 427, and optical block 427 And an optical fiber 428 disposed between the electrostatic mirror 425 and the electrostatic mirror 425.
The optical block 427 includes a laser diode (LD), a beam splitter, a photo detector, and the like. The photo detector is, for example, a quadrant detector.
[0034]
The beam light emitted from the laser diode in the optical block 427 passes through the beam splitter, enters the optical fiber 428, propagates in the optical fiber 428, is irradiated on the electrostatic mirror 425, and is deflected by the electrostatic mirror 425. Then, the light passes through the optical system 426, enters the objective lens 424, is converged by the objective lens 424, and is irradiated onto the recording surface of the magneto-optical disk 410.
The reflected light from the magneto-optical disk 410 passes through the opposite optical path, enters the beam splitter in the optical block 427, is deflected by the beam splitter, and enters the photodetector.
[0035]
In the tracking control of the magneto-optical head 420, the arm 421 is moved in a predetermined angle range (perpendicular to the paper surface) by a surface parallel to the surface of the magneto-optical disk by an actuator such as a voice coil motor (not shown) and an electrostatic mirror. 425 is also used for positioning on a predetermined track of the magneto-optical disk 410.
Since the slider 423 floats by a predetermined distance from the magneto-optical disk 410 by the wind pressure accompanying the rotation of the magneto-optical disk 410, the objective lens 424 is separated from the magneto-optical disk 410 by a predetermined distance, so that focus control is unnecessary. .
The problem of the fourth prior art will be described later.
[0036]
[Problems to be solved by the invention]
The problem of the first prior art described with reference to FIG. 12 will be described.
In recent years, magneto-optical disks have become increasingly dense, and there is a demand for miniaturization and cost reduction of magneto-optical heads or magneto-optical pickups. However, it is difficult to miniaturize the above-mentioned integral feed magneto-optical pickup 120. There is a problem that it is difficult to reduce the price. In particular, the magneto-optical pickup 120 and the magneto-optical disk 110 are close to each other, and the limit that the electromagnetic actuator cannot properly control the focus control is encountered.
[0037]
Furthermore, when it is assumed to be applied to a “multi-layer” optical recording / reproducing apparatus in which a plurality of magneto-optical disks are stacked along the same rotation axis in order to increase the recording capacity, FIG. It is difficult to apply the integrated feed type magneto-optical pickup described above with reference to the multi-plate optical recording / reproducing apparatus.
[0038]
The problem of the second prior art described with reference to FIG. 13 will be described.
The structure of the magneto-optical pickup 220 for driving the uniaxial actuator 222 by the voice coil motor (VCM) 223 is complicated, and the size of the magneto-optical pickup 220 is still large.
Further, since the optical path from the optical block 221 to the objective lens is too long, the reliability is low, miniaturization is difficult, and it is difficult to reduce the price.
Further, it is practically difficult to apply to a “multi-layer” optical recording / reproducing apparatus in which a plurality of magneto-optical disks 210 having such a complicated structure are stacked along the same rotation axis.
[0039]
The problem of the third prior art described with reference to FIG. 14 will be described.
(1) In the magneto-optical head 320, the arm 321 and the light source module 326 move together during near-field recording operation, so that the inertial mass when moving the arm 321 increases, and the seek time is increased. There is a disadvantage of becoming longer. In addition, a voice coil motor 325 that outputs a considerably large power is used. As a result, the apparatus configuration becomes large, it is difficult to reduce the price, and there is a limit to downsizing.
[0040]
(2) In addition to the objective lens 327 and the magnetic field modulation coil, since the first mirror 323 is mounted on the magneto-optical head 322 that floats in response to the rotation of the magneto-optical disk 310, the mass of the magneto-optical head 322 is large. Therefore, a sufficient flying height may not be obtained.
[0041]
(3) In the magneto-optical head 320, since the optical path between the first mirror 323 and the second mirror 324 is open, the reliability of light propagating through this optical path is not guaranteed. In place of the first mirror 323 and the second mirror 324, a method using a polarization-maintaining optical fiber is also conceivable. However, in this case, a decrease in signal quality becomes a problem.
Since the magneto-optical head 320 has a large apparatus configuration, it is not suitable for a “multi-layered” multi-plate magneto-optical recording / reproducing apparatus in which a plurality of magneto-optical disks are stacked along the same rotation axis.
[0042]
The problem of the fourth prior art described with reference to FIG. 15 will be described.
Since the magneto-optical head 420 illustrated in FIG. 15 uses the optical fiber 428, there is a problem that the optical fiber 428 becomes a load with respect to the rotation operation of the arm 421 and deteriorates the rotation operation characteristic of the arm 421. is there.
Further, since optical coupling is performed between the optical fiber 428 and the electrostatic mirror 425, there is a disadvantage that the optical coupling efficiency (coupling efficiency) is lowered.
In addition, since the magneto-optical head 420 cannot obtain a push-pull signal, tracking control must be performed by a sample servo.
[0043]
The various conventional magneto-optical head devices or magneto-optical pickups described above encounter unique problems.
As described above, the magneto-optical head or the magneto-optical pickup used for the magneto-optical disk has been described as a prior art. However, the same problem as described above is also encountered in an optical pickup that performs signal reading only with an optical signal.
[0044]
In particular, there is a demand for a compact optical head applicable to recent miniaturization of magneto-optical recording media, near-field recording, and the like, and an optical recording / reproducing apparatus using the optical head. .
[0045]
Furthermore, an increase in recording capacity is desired. As one of the methods, there is a demand for a “multi-layered” magneto-optical recording / reproducing apparatus in which a plurality of magneto-optical disks and the like are stacked along the same rotation axis. There is a demand for an optical head such as a magneto-optical head and a magneto-optical pickup suitable for a magnetic recording / reproducing apparatus.
[0046]
An object of the present invention is to provide an optical head device that can be manufactured in a small size and at a low cost.
Another object of the present invention is to provide a small-sized optical head device that can be suitably used for near-field recording, has no restrictions on signal detection, and has high reliability.
Still another object of the present invention is to provide an optical head device suitable for a multi-plate optical recording / reproducing apparatus.
[0047]
Still another object of the present invention is to provide an optical recording / reproducing apparatus using the above-described optical head device.
[0048]
[Means for Solving the Problems]
  According to the present invention, there is provided an optical head device for optically writing and / or reading data on an optical rotary recording medium,
  An arm, an elastic suspension member having one end fixed to the lower surface of the arm, a slider mounted on the free end of the suspension member and mounted with an objective lens, a light emitting device, a beam splitter device, and a light receiving device An optical unit mounted on the arm, and an optical unit mounted on the arm so that an optical axis of the optical unit coincides with an optical axis of the objective lens mounted on the slider.The optical unit is displaced to move in a direction perpendicular to the surface of the optical rotary recording medium, or the optical unit is moved to move in a direction parallel to the surface of the optical rotary recording medium. And a piezo element or an electromagnetic actuator for adjusting the optical path length between the objective lens and the optical unit.And an optical path length adjusting actuator,
  The slider isAccording to the change in the atmospheric pressure accompanying the rotation of the optical rotary recording medium by a predetermined distance that does not require focus controlLevitating from the surface of the optical rotary recording medium,
  An optical head device is provided.
[0049]
This optical head device is a flying head type magneto-optical head, and a slider on which an objective lens is mounted floats a predetermined distance from the optical rotary recording medium in accordance with the rotation of the optical rotary recording medium. This eliminates the need for focus control and only requires tracking control.
[0050]
If the slider is only an objective lens, or if the optical rotary recording medium is a magneto-optical disk, etc., it is only equipped with magnetic field application means such as a magnetic field modulation coil. The ascending response is quick.
[0051]
The optical unit is attached to a fixed part of an arm that moves during tracking control, and is close to the objective lens. Therefore, the decrease in optical coupling efficiency is also low.
[0052]
The optical head device of the present invention is small and lightweight.
[0053]
Specifically, the optical unit is mounted at the position of the arm that directly faces the objective lens mounted on the slider.
The focus distance adjustment actuator moves the optical unit in a direction orthogonal to the surface of the optical rotary recording medium (that is, moves in the focus direction) or parallel to the surface of the optical rotary recording medium. It is an actuator that is displaced to move in a direction (that is, to move in the tracking direction). When the optical unit is moved in the focus direction, the optical path length changes. When the optical unit is moved in the tracking direction, the optical path in the tracking direction changes. In this specification, the change in the optical path length in the focus direction and the change in the optical path in the tracking direction are handled in the same manner, and these are collectively referred to as substantially adjusting the optical path length.
[0054]
More specifically, the optical unit is mounted on the upper surface on the free end side of the arm so that the optical axis is oriented in the horizontal direction. In this case, the focus distance adjusting actuator is fixed to the upper surface of the arm so as to move the optical system in the horizontal direction, and the horizontal light from the optical unit is applied to the upper surface of the arm at the lower portion of the arm. There is provided a deflecting means for directing the objective lens located at the position.
An opening may be provided in the arm at a portion along the optical axis between the optical unit and the objective lens via the deflecting unit.
[0056]
The optical rotary recording medium is an optical rotary recording medium of a type in which data is written in a magnetic field application state or a magnetic field modulation state. In that case, an objective lens and magnetic application means or magnetic field modulation means are mounted on the slider.
[0057]
Alternatively, the optical rotary recording medium is an optical rotary recording medium of a type in which data is read in a no magnetic field state. In that case, only the objective lens is mounted on the slider.
[0058]
Furthermore, it may further include an arm drive actuator that drives the arm to move the slider in a track direction of the optical rotary recording medium.
[0059]
Furthermore, according to the present invention, (1) an optical rotary recording medium, (2) an optical head device for optically writing and / or reading data on the optical rotary recording medium, and (3 There is provided an optical recording / reproducing apparatus having a control device for driving the optical head device to write data to and / or read data from the optical rotary recording medium.
The optical head device has the above-described configuration.
The control device drives a tracking servo control means for controlling the track position by driving the arm drive actuator and an optical path length of an optical system of the optical head device by driving the optical path length adjusting actuator, specifically, And an optical path length adjusting unit that adjusts a distance (optical path length) between the objective lens and the optical unit.
[0060]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an optical head device and an optical recording / reproducing apparatus using the optical head device of the present invention will be described.
Hereinafter, a magneto-optical head will be described as an exemplary embodiment of the optical head device of the present invention. However, the optical head of the present invention is meant to include both a magneto-optical head and an optical head.
Similarly, a magneto-optical recording / reproducing apparatus will be described below as an embodiment of the optical recording / reproducing apparatus of the present invention. The optical recording / reproducing apparatus of the present invention includes a magneto-optical recording / reproducing apparatus and an optical recording / reproducing apparatus. It is meant to include devices.
In this specification, the optical recording / reproducing apparatus is used in a broad sense that means one of an optical recording apparatus, an optical reproducing apparatus, and an optical recording and reproducing apparatus.
[0061]
First embodiment
FIG. 1 is a cross-sectional configuration diagram of a magneto-optical head device as a first embodiment of an optical head device of the present invention. FIG. 1 also shows a cross-sectional configuration of a magneto-optical (MO) disk as an embodiment of an optical recording medium.
FIG. 2 is an enlarged view showing an example of an optical unit mounted on the magneto-optical head device illustrated in FIG.
FIG. 3 is a block diagram of a control device that drives and controls the magneto-optical head device illustrated in FIG.
When the magneto-optical head apparatus illustrated in FIG. 1, the MO disk, and the control apparatus illustrated in FIG. 2 are combined, the magneto-optical recording / reproducing apparatus of the first embodiment of the optical recording / reproducing apparatus of the present invention is Become.
[0062]
MO disk
The present embodiment shows an example in which the MO disk 3 is used as the optical rotary recording medium of the present invention.
The MO disk 3 is a bonded MO disk in which two MO disks 3A and 3B are bonded together, and a recording film 32 is formed below the top coat 31 in each of the MO disks 3A and 3B.
[0063]
Magneto-optical head device
The magneto-optical head device 1 will be described with reference to FIGS.
The magneto-optical head device 1 has an arm 11. The arm 11 has a thick part 11A and a thin part 11B.
The magneto-optical head device 1 is fixed to a suspension (suspending member) 12 having one end fixed to the lower surface of the thick portion 11A of the arm 11 and the other end being a free end, and a free end of the suspension 12. And a magnetic field modulation coil 14 mounted on the slider 13 and an objective lens 15 mounted on the slider 13 in the vicinity of the magnetic field modulation coil 14.
The magneto-optical head device 1 is further positioned at the end of the thin portion 11B of the arm 11 and is fixed to the lower surface of the thin portion 11B facing the objective lens 15 as a piezo as an example of the optical path length adjusting actuator of the present invention. It has the element 16 and the optical part 17 fixed to the lower surface of the piezo element 16.
[0064]
Since the objective lens 15 and the magnetic field modulation coil 14 need to be close to the MO disk 3, they are mounted on the slider 13 close to the MO disk 3.
On the other hand, since the slider 13 floats with respect to the MO disk 3 by the flying head method, the slider 13 needs to be as light as possible. For this reason, the optical unit 17 is not mounted on the slider 13 and the mass of the slider 13 is reduced.
[0065]
That is, the slider 13 floats from the upper surface of the MO disk 3 by a predetermined distance d by the wind pressure (or atmospheric pressure, also referred to as an air bearing) of the MO disk 3 rotated by a spindle motor (not shown). That is, the magneto-optical head device 1 is a flying head type (head floating type) magneto-optical head device.
Thus, since the slider 13 is levitated by the wind pressure accompanying the rotation of the MO disk 3, the mass of the slider 13, the magnetic field modulation coil 14 and the objective lens 15 needs to be as small as possible and the dimensions thereof must be reduced. Manufactured with a soft and elastic material, or manufactured into a shape that exhibits elasticity.
[0066]
In particular, the mass of the slider 13, the magnetic field modulation coil 14, and the objective lens 15 needs to be as small as possible and small in size in order to adapt to the recent high-density and small MO disk 3.
The dimensions of the slider 13 are, for example, about 2.85 × 2.24 × 0.86 (mm), and the weight of the suspension 12 is 7 g.
When the magneto-optical head device 1 is manufactured under such conditions, the slider 13 can easily float and the flying height of the slider 13 can be appropriately secured.
[0067]
Therefore, when the magneto-optical head device 1 of the present embodiment is used, focus control is unnecessary. The distance between the optical unit 17 and the objective lens 15 is directly adjusted using a piezo element 16 as an example of an optical path length adjusting actuator, and finally the magneto-optical head device 1 is adjusted. Adjust the optical path length of the entire optical system.
In the present specification, the entire optical system of the magneto-optical head device 1 includes a glass layer on the surface of the MO disk 3, and includes the objective lens 15, the optical unit 17, and various optical elements not illustrated in FIG. Is a generic term. Therefore, in this specification, the optical system does not mean only the optical unit 17.
[0068]
Of course, the piezo element 16 as an optical path length adjusting actuator is used to move (displace) the optical unit 17 and directly adjust the distance between the optical unit 17 and the objective lens 15. By this position adjustment, the optical path length of the entire optical system of the magneto-optical head device 1 can be adjusted.
[0069]
FIG. 2 is a diagram illustrating a configuration example of the optical unit 17 illustrated in FIG. For convenience of illustration, the optical unit 17 is illustrated upside down from the state illustrated in FIG.
The optical unit 17 is an optical unit (package) including a micro-prism 171 functioning as a beam splitter, a laser diode (LD) 172, and a photo detector (PD) IC 17A integrated with a photo detector 173, and a quarter wavelength plate and the like. 17B.
[0070]
In the optical unit 17, the beam light emitted from the LD 172 is deflected on the slope of the microprism 171, travels upward in FIG. 2 and downward in FIG. 1, enters the objective lens 15, and is converged by the objective lens 15. The recording film 32 of the MO disk 3A is irradiated.
The light reflected from the recording film 32 of the MO disk 3 </ b> A passes through the objective lens 15, enters the inclined surface of the microprism 171, enters the microprism 171, and enters the photodetector 173.
Thus, the optical axis of the optical unit 17 and the optical axis of the objective lens 15 coincide with each other.
[0071]
The photo detector 173 is, for example, a known quadrant photo detector, and detects signals used for generating a tracking error signal, a focus error signal, an RF signal, and the like.
[0072]
The optical part 17 in this Embodiment has illustrated about the case where finite light is used. However, a collimator can be inserted after the LD 172 to generate parallel light.
In the following description, the case where finite light is used will be exemplified.
[0073]
The piezo element 16 illustrated in FIG. 1 is an element that causes a minute displacement when a voltage is applied. Further, the magnitude and direction of displacement of the piezo element 16 are defined by the crystal structure and the direction of the applied voltage.
In the present embodiment illustrated in FIG. 1, by applying a voltage to the piezo element 16, the piezo element 16 is displaced in a direction perpendicular to the MO disk 3, and in the illustrated vertical direction VV. The distance of the optical unit 17 with respect to is changed.
The distance between the optical unit 17 and the objective lens 15 changes due to the displacement of the optical unit 17. Therefore, the optical path length of the optical system of the magneto-optical head device 1 including the optical unit 17 and the objective lens 15 can be changed.
As described above, the piezo element 16 directly changes the distance (optical path length) between the optical unit 17 and the objective lens 15 in accordance with the applied voltage, and finally the magneto-optical head device. It is used as an optical path length adjusting actuator for adjusting the optical path length of the optical system 1.
[0074]
In the tracking control, the arm 11 is driven by the voice motor coil 19. In the tracking control, the piezoelectric element 16 and the optical unit 17 mounted on the thin portion 11B of the arm 11, the slider 13 mounted on the suspension 12 fixed to the thick portion 11A, and the magnetic field modulation mounted on the slider 13 The coil 14 and the objective lens 15 move together.
In particular, in the illustrated magneto-optical head device 1, since the distance between the objective lens 15 and the optical unit 17 is short and a mirror, an optical fiber, and the like are unnecessary, the optical coupling efficiency is high and the reliability is high.
[0075]
When tracking control is performed by rotating the arm 11 in a plane parallel to the surface of the MO disk 3 (or in a direction perpendicular to the paper surface), the right side of the thick portion 11A of the arm 11 is rotatable about the shaft 18. The arm 11 is rotated around a shaft 18 by a rotary actuator, for example, a voice motor coil 19 in a range of a predetermined angle in a direction perpendicular to the paper surface. Tracking of the track of the MO disk 3 can be performed by such rotation of the arm 11.
[0076]
Control device
The control device 4 illustrated in FIG. 3 includes a magnet drive unit 41, a laser drive unit 42, a detection signal processing unit 43, a tracking servo controller 44, an optical path length adjustment unit 45, a pre-demodulation processing unit 46, and a demodulation unit. A unit 47, a system controller 48, a modulation unit 49, a memory controller 50, and a RAM 51 are included. The control device 4 further includes interfaces 52 and 53 that perform signal transfer with the host computer, for example.
Since the slider 13 of the magneto-optical head device 1 is floated by the wind pressure generated by the rotation of the MO disk 3, the distance of the objective lens 15 to the surface of the MO disk 3 is normally maintained at a predetermined value. There is no section.
However, an optical path length adjustment unit 45 is added to finely adjust the optical path length between the objective lens 15 and the optical unit 17 using the piezo element 16.
[0077]
When the system controller 48 receives a read or write command from an external device such as a host computer via the interface 53, the memory controller 50, the modulation unit 49, the pre-demodulation processing unit 46, and the demodulation unit 47 according to the read or write. The tracking servo controller 44 and the optical path length adjusting unit 45 are controlled.
When writing data, data to be written to the MO disk 3 is recorded in the memory controller 50 via the interface 52 and temporarily stored in the RAM 51. Conversely, when data is read, the data read from the MO disk 3 by the photodetector 173, the detection signal processing unit 43, the pre-demodulation processing unit 46, and the demodulation unit 47 and temporarily reproduced is stored in the RAM 51 via the memory controller 50. And sent to the host computer via the interface 52.
[0078]
The modulation unit 49 is driven from the system controller 48 at the time of data writing, and adds data for error correction code (ECC), run length restriction (RLL), modulation processing such as NRZI or NRZ (code) for the data read from the RAM 51. Process).
[0079]
The magnet drive unit 41 drives the magnetic field modulation coil 14 in accordance with a signal from the modulation unit 49 when writing data to the MO disk 3.
[0080]
The laser driving unit 42 drives a laser diode (LD) 172 in the optical unit 17.
[0081]
The detection signal processing unit 43 receives a detection signal from the photo detector 173 in the optical unit 17 and calculates a tracking error signal, a focus error signal, an RF signal, and the like.
[0082]
The tracking servo controller 44 drives the voice motor coil 19 with reference to the tracking error signal detected by the detection signal processing unit 43 to perform tracking control of the magneto-optical head 1.
[0083]
The optical path length adjustment unit 45 drives the piezo element 16 with reference to the focus error signal detected by the detection signal processing unit 43 and adjusts the position of the optical unit 17 in the vertical direction VV. The optical path length of the optical system of the magneto-optical head device 1 is adjusted by changing the distance from the objective lens 15.
[0084]
The demodulation preprocessing unit 46 includes an A / D conversion circuit, an equalizer circuit, a phase synchronization circuit (PLL), a Viterbi decoding circuit, and the like. The demodulation preprocessing unit 46 operates when reading data.
The A / D conversion circuit converts the analog signal calculated by the detection signal processing unit 43 into a digital signal.
The equalizer circuit equalizes the signal converted into a digital signal.
The PLL reproduces the clock signal.
The Viterbi decoding circuit decodes the signal recorded on the MO disk 3 from the RF signal using the reproduced clock.
The pre-demodulation processing unit 46 also has an address decoder, and calculates the address of the magneto-optical head 1 from the signal from the detection signal processing unit 43.
[0085]
The demodulator 47 operates at the time of data reading. The data demodulated by the demodulator 47 is processed in reverse to the process modulated by the modulator 49 to reproduce the original data and send it to the memory controller 50. To do.
[0086]
Operation of magneto-optical recording / reproducing device
The operation of the magneto-optical recording / reproducing apparatus of this embodiment will be described.
The MO disk 3 is rotated at a predetermined rotational speed by a spindle motor (not shown). Due to the rotation of the MO disk 3, the slider 13 of the magneto-optical head apparatus 1 floats a predetermined distance from the surface of the MO disk 3.
[0087]
When a data write request is issued from the host computer to the system controller 48 via the interface 53, the system controller 48 operates the memory controller 50 and records it in the RAM 51 to be written transferred via the interface 52. In parallel with this operation, the demodulator 47 controls the tracking servo controller 44, the optical path length adjuster 45, and the modulator 49. Details are described below.
[0088]
The system controller 48 drives the tracking servo controller 44 to position the magneto-optical head 1 at a designated address on the MO disk 3 (tracking control is performed).
At the time of this tracking operation, all components mounted on (attached to) the arm 11 driven by the voice motor coil 19, that is, the piezo element 16, the optical unit 17, the suspension 12, the slider 13, the magnetic field modulation coil 14, and the objective. The lens 15 integrally moves in a direction parallel to the surface of the MO disk 3.
[0089]
In the on-track state, the system controller 48 sends the data to be written recorded in the RAM 51 to the modulation unit 49 via the memory controller 50.
The modulation unit 49 performs the various modulation processes described above on the input data to be written.
The magnet drive unit 41 drives the magnetic field modulation coil 14 based on the modulation result in the modulation unit 49, and the laser drive unit 42 drives the laser diode 172 in the optical unit 17 based on the modulation result in the modulation unit 49.
As a result, the magnetic field modulation coil 14 mounted on the slider 13 that floats a predetermined distance d from the MO disk 3 modulates the magnetic field of the recording film 32 of the lower MO disk 3.
The laser beam emitted from the laser diode 172 illustrated in FIG. 2 toward the microprism 171 is deflected by the slope of the microprism 171 and enters the objective lens 15, where it converges and is recorded on the recording film 32 of the MO disk 3. The data is written by irradiation.
[0090]
The slider 13 floats from the surface of the MO disk 3 by a distance d due to the wind pressure accompanying the rotation of the MO disk 3.
The optical path length adjustment unit 45 drives the piezo element 16 to adjust the distance (optical path length) between the objective lens 15 and the optical unit 17 when the focus error signal calculated by the tracking servo controller 44 exceeds a predetermined value. To do.
[0091]
When a data read request is sent from the host computer to the system controller 48 via the interface 53, the system controller 48 drives the tracking servo controller 44 so that the magneto-optical head 1 is positioned at the designated address of the MO disk 3. Let
In the on-track state, the system controller 48 drives the demodulator 47 to demodulate the data recorded on the MO disk 3 restored by the pre-demodulation processor 46 to the original data that is not modulated or encoded.
The demodulated data is temporarily recorded in the RAM 51 via the memory controller 50, and when a predetermined amount of data is accumulated, it is sent to the host computer via the interface 52.
Also in this case, the optical path length adjustment unit 45 adjusts the optical path length of the optical system by adjusting the distance of the optical unit 17 with respect to the objective lens 15 using the piezo element 16 as described above.
[0092]
As an example of the present embodiment, the flying distance d of the slider 13, the voltage V applied to the piezo element 16, and the displacement amount when the voltage is applied, that is, the optical path length adjustment amount δ are shown below.
[0093]
[Table 1]
Table 1
d: Near field (NFR): 20 mm to 60 mm
In the case of high NA (0.85 to 0.95), 0.1 μm to 0.4 μm
V: Several V to several tens V
δ: about several μm to 100 μm (DC adjustment, etc.)
[0094]
As described above, when the magneto-optical head device 1 according to the present embodiment is used, the objective lens 15 and the magnetic field modulation coil 14 mounted on the slider 13 are appropriately levitated from the MO disk 3, so that basically the focus Control becomes unnecessary. Therefore, time spent for focus control is unnecessary, and responsiveness is high.
[0095]
Further, the piezo element 16 is driven under the control of the optical path length adjustment unit 45 to displace the optical unit 17 mounted on the thick portion 11A of the arm 11 so that the distance between the objective lens 15 and the optical unit 17 is increased. The optical path length of the optical system can be adjusted by adjusting the distance.
[0096]
Since the optical unit 17 that houses the microprism 171, the laser diode (LD) 172, and the photodetector 173 of the present embodiment is located immediately above the objective lens 15 mounted on the slider 13, The length is short, the optical coupling efficiency is high, and the magneto-optical head device 1 can be manufactured in a small size.
[0097]
Furthermore, since the present embodiment integrally moves during tracking control, the present embodiment overcomes the problems associated with the separation of the optical unit, the objective lens, and the magnetic field modulation coil in the prior art described above.
[0098]
Since the optical unit 17 is mounted not on the slider 13 on which the optical unit 17 floats but on the thin portion 11B that is a fixed unit of the arm 11, the optical unit 17 does not affect the focus control. That is, in the magneto-optical head device 1 of the present embodiment, there are few restrictions on the weight, restrictions, dimensions, etc. of the optical unit 17. Therefore, the configuration of the optical unit 17 can be made arbitrary.
[0099]
Since the magneto-optical head 1 can be made very small, it can be applied as a magneto-optical head such as a recent magneto-optical disk such as a MO disk of 5 inches or less.
[0100]
Modification of the first embodiment
Further, modifications of the magneto-optical head device 1 and the control device 4 of the first embodiment will be described.
[0101]
First modification of the first embodiment
Although the optical unit 17 described above is exemplified for the case where finite light is used, in the present embodiment, for example, a collimator lens is positioned behind the laser diode (LD) 172 to be parallel light, and parallel light is used. The optical unit 17 can also be used.
[0102]
Second modification of the first embodiment
In the embodiment described above, the case where the arm 11 is rotated by the voice motor coil 19 to perform the tracking control has been described. However, the arm 11 is moved forward or backward in the axial direction by using the voice motor coil or other actuator. It is also possible to adopt a configuration in which tracking control is performed by performing a straight movement. Therefore, in the present invention, the driving method of the arm 11 is not limited to the rotation method.
Various known techniques such as a configuration using one axis, a configuration using two axes, and the like can be applied as a configuration for performing such a linear movement.
[0103]
Third modification of the first embodiment
In the embodiment described above, an example in which the magnetic field modulation coil 14 is mounted on the optical unit 17 is shown. However, other magnetic field applying means may be appropriately mounted according to the rotary recording medium and the recording method. it can.
[0104]
Fourth modification of the first embodiment
In the above-described embodiment, the case where the piezo element 16 is used as the optical path length adjusting actuator has been described. However, as the optical path length adjusting actuator, for example, a known microactuator or electromagnetic actuator may be used instead of the piezo element 16. Can be used.
[0105]
FIG. 4 is a diagram showing a cross-sectional configuration of a magneto-optical head device 1A in which an electromagnetic actuator 21 is mounted on a thin portion 11B of an arm 11 as an optical path length adjusting actuator. The optical unit 17 is disposed at a position surrounded by the electromagnetic actuator 21, and the optical unit 17 moves up and down perpendicular to the surface of the MO disk 3 by the operation of the electromagnetic actuator 21. The other parts are the same as described above with reference to FIG.
[0106]
FIG. 5 is an enlarged diagram illustrating the positional relationship among the electromagnetic actuator 21, the optical unit 17, the magnetic field modulation coil 14, and the objective lens 15 as a more specific example of the embodiment illustrated in FIG. 4. It is.
Electromagnets 17a and 17b are attached to both sides of the optical unit 17, and by passing an electric current to these electromagnets, the optical unit is caused by the attraction and exclusion forces with the permanent magnets 21a and 21b fixed to the thin portion 11B of the arm 11. 17 is moved up and down in the vertical direction VV. As a result, it is possible to adjust the distance from the objective lens 15 located at the lower portion mounted on the slider 13.
In this example, the magnetic field modulation coil 14 is a thin film coil.
[0107]
The deformation modes described above can be combined as appropriate.
Even in the above-described modification, the same effect as described above can be obtained.
[0108]
Second embodiment
FIG. 6 is a sectional view of a magneto-optical head device as a second embodiment of the optical head device of the present invention.
FIG. 7 is a diagram showing the configuration of the control device 4A.
When the magneto-optical head device illustrated in FIG. 6, the MO disk, and the control device illustrated in FIG. 7 are combined, the magneto-optical recording / reproducing device of the second embodiment of the optical recording / reproducing device of the present invention is Become.
[0109]
The magneto-optical head apparatus of FIG. 6 corresponds to the magneto-optical head apparatus of FIG. However, in the magneto-optical head device 1B illustrated in FIG. 6, the piezo element 16A mounted at the tip of the thin portion 11B of the arm 11 is placed in the horizontal direction HH parallel to the surface of the MO disk 3, that is, the MO disk 3 Displace in the radial direction. As a result, the optical unit 17 mounted on the piezo element 16A is moved in the tracking direction of the MO disk 3.
[0110]
As described above, the piezoelectric element 16A is an element that causes a minute displacement when a voltage is applied. Further, the magnitude and direction of displacement of the piezo element 16A are defined by the crystal structure and the direction of the applied voltage.
In the present embodiment illustrated in FIG. 6, a voltage is applied to the piezo element 16A to displace the piezo element 16A in a direction parallel to the surface of the MO disk 3, that is, in the radial direction of the MO disk 3. The amount of displacement changes according to the value of the voltage applied to the piezo element 16A.
[0111]
The optical unit 17 moves in the tracking direction of the MO disk 3 according to the displacement of the piezo element 16A.
Due to the displacement of the optical unit 17 in the horizontal direction, the center of the optical axis between the optical unit 17 and the objective lens 15 is shifted, and the “optical path in the tracking direction” changes. In this way, the “optical path in the tracking direction” between the objective lens 15 and the optical unit 17 can be adjusted by displacing the optical unit 17 along the surface of the MO disk 3.
In this specification, not only adjusting the optical path length in the focus direction but also adjusting the optical path in the tracking direction in this way is called optical path length adjustment in a broad sense.
[0112]
In this way, the piezo element 16A directly changes the “optical path in the tracking direction” between the optical unit 17 and the objective lens 15 according to the applied voltage, and finally the magneto-optical head. Since the optical path length of the optical system of the apparatus 1 is adjusted, it is called an optical path length adjusting actuator in a broad sense.
[0113]
The configuration of the optical unit 17 is the same as that illustrated in FIG. 2, but the direction of displacement by the piezo element 16 is different, so that the optical unit 17 of FIG. The direction has also changed. However, the operating principle is the same as in the first embodiment.
[0114]
The MO disk 3 is the same as that described with reference to FIG.
[0115]
The control device 4A in FIG. 7 is substantially the same as the control device 4 illustrated in FIG. However, the optical path length adjustment unit 45A is also slightly different from the optical path length adjustment unit 45 in response to the direction of displacement of the piezo element 16A. However, the principle of the method for adjusting the optical path length is the same as in the first embodiment.
Also in this case, the optical path length adjustment unit 45A adjusts the “optical path in the tracking direction”. However, in the present specification, in the broad sense, the optical path length adjustment unit 45A adjusts the optical path length in the focus direction. Called the adjustment unit.
[0116]
As described above, the optical path length of the flying head type magneto-optical head apparatus 1 can also be adjusted by the second embodiment described with reference to FIGS.
When the magneto-optical head device 1 illustrated in FIG. 1 is compared with the magneto-optical head device 1A illustrated in FIG. 6, the magneto-optical head device 1A illustrated in FIG. 6 is not displaced in the vertical direction VV. This is advantageous when the vertical dimension is limited.
[0117]
Modification of the second embodiment
FIG. 8 is a block diagram of a magneto-optical head apparatus 1C as a modification of the second embodiment of the present invention.
The magneto-optical head device 1C illustrated in FIG. 8 has a configuration similar to that of the magneto-optical head device 1A illustrated in FIG. However, in the magneto-optical head apparatus 1C illustrated in FIG. 8, the electromagnetic actuator 21 mounted on the thin part 11B of the arm 11A as an optical path length adjusting actuator is configured so that the optical part 17 is parallel to the surface of the MO disk 3. That is, the optical path length of the optical system of the magneto-optical head apparatus 1C is adjusted by displacing in the tracking direction. The rest is the same as the magneto-optical head apparatus 1A illustrated in FIG.
Note that adjusting the optical path length of the optical system of the magneto-optical head apparatus 1C by displacing the optical unit 17 in the tracking direction is substantially the same as the magneto-optical head apparatus 1B illustrated in FIG.
[0118]
Third embodiment
FIG. 9 is a sectional view of a magneto-optical head device as a third embodiment of the optical head device of the present invention.
The magneto-optical head device 1D illustrated in FIG. 9 uses an arm 11a having a uniform thickness, and fixes the mirror 23 on the upper surface in the vicinity of the free end of the arm 11a while maintaining an angle of 45 degrees with the upper surface of the arm 11a. Further, a piezo element 16 is fixed on the upper surface of the arm 11 a, and an optical unit 17 is fixed on the piezo element 16. Other configurations are basically the same as those of the first embodiment described with reference to FIG.
[0119]
This magneto-optical head device 1D is also a flying head type magneto-optical device in which the slider 13 part is levitated by the wind pressure of the MO disk 3 as in the magneto-optical head devices 1, 1A, B, and C of the first and second embodiments. It is a head device.
[0120]
The piezo element 16D can move the optical unit 17 along the upper surface of the arm 11a in the axial direction of the arm 11a (direction parallel to the paper surface) in response to voltage application. Unlike the arrangement described with reference to FIG. 2, the optical unit 17 is arranged so that the beam light emitted from the laser diode (LD) 172 is incident on the mirror 23 when deflected by the slope of the microprism 171. is there.
The mirror 23 deflects the incident beam light to the objective lens 15 directly below. Therefore, a hole 1a1 through which beam light passes is formed below the mirror 23 of the arm 11a.
[0121]
The beam light incident on the objective lens 15 is converged and applied to the recording film 32 of the MO disk 3.
The light reflected by the recording film 32 passes through the objective lens 15 and enters the mirror 23, is deflected toward the optical unit 17 by the mirror 23, and enters the photodetector 173 in the optical unit 17.
[0122]
In the magneto-optical head apparatus 1D illustrated in FIG. 9, the optical unit 17 moves forward or backward toward the mirror 23 by the piezo element 16D. As a result, the “optical path in the tracking direction” between the objective lens 15 and the optical unit 17 changes, and the optical path length of the magneto-optical head device 1D changes. That is, also in the third embodiment, as in the first embodiment, the distance between the objective lens 15 and the optical unit 17 (“optical path in the tracking direction”) is adjusted to provide a flying head type magneto-optical head device. Complements focus control.
[0123]
When comparing the magneto-optical head device 1D of the third embodiment illustrated in FIG. 9 with the magneto-optical head device 1 of the first embodiment, the magneto-optical head device 1D illustrated in FIG. This is suitable for application when there is a spatial margin above. That is, the magneto-optical head apparatus 1D is mounted only in comparison with the magneto-optical head apparatus 1 of the first embodiment that moves in the vertical direction because the optical unit 17 only moves in the horizontal direction on the arm 11a. Etc. are advantageous.
[0124]
The control device 4 of FIG. 3 can also be used when the magneto-optical head device 1D of the third embodiment is used. Therefore, the operation as the magneto-optical recording / reproducing apparatus is the same as that of the first embodiment.
[0125]
The control device of the third embodiment basically has the same configuration as the control device illustrated in FIG. 3 and performs the same operation.
[0126]
Modification of the third embodiment
As a modification of the third embodiment, the optical path length adjusting actuator is replaced with the above-described piezo element 16D, and an electromagnetic actuator corresponding to the electromagnetic actuator 21A that displaces the optical unit 17 in the horizontal direction HH illustrated in FIG. Can be used.
[0127]
Fourth embodiment
FIG. 10 is a cross-sectional configuration diagram of a magneto-optical head device as a fourth embodiment of the optical head device of the present invention.
The magneto-optical head device 1E illustrated in FIG. 10 has a configuration similar to that of the magneto-optical head device 1D illustrated in FIG. 9, but the piezo element 16E is perpendicular to the piezo element 16 illustrated in FIG. Displacement to V-V.
[0128]
Due to the displacement of the piezo element 16E in the vertical direction VV, the vertical position of the optical unit 17 changes, so that the optical path length of the optical system by the mirror 23 and the objective lens 15 changes. Therefore, also in the magneto-optical head apparatus 1E of FIG. 10, the optical path length of the optical system of the magneto-optical head apparatus 1E can be adjusted using the piezo element 16E.
[0129]
Modification of the fourth embodiment
As a modification of the fourth embodiment, an electromagnetic actuator corresponding to the electromagnetic actuator 21 that displaces the optical unit 17 in the vertical direction VV illustrated in FIG. 4 by changing the optical path length adjusting actuator to the above-described piezo element 16E. Can be used.
[0130]
Fifth embodiment
FIG. 11 shows, as a fifth embodiment of the present invention, a magneto-optical recording in which a plurality of magneto-optical disks are stacked and multilayered along the rotation axis, and data is written to and read from the plurality of magneto-optical disks simultaneously. -It is a fragmentary perspective view of a reproducing | regenerating apparatus.
The magneto-optical head used for one magneto-optical disk is the one described in the above embodiment. Since the above-described magneto-optical head is small and lightweight, a magneto-optical recording / reproducing apparatus can be used even when a plurality of magneto-optical heads are used for data writing and reading of a plurality of multi-layered magneto-optical disks illustrated in FIG. The overall apparatus configuration can be reduced in size. As a result, such a magneto-optical recording / reproducing apparatus can be manufactured at low cost or light weight, and can be applied to various applications.
[0131]
Sixth embodiment
In the above-described embodiment, the case where the MO disk 3 is used as the optical rotary recording medium has been illustrated. However, the present invention is not limited to the application to the MO disk, and various optical disks, CDs, and the like that do not involve magnetic action. The present invention can also be applied to the optical rotating recording medium. In the case of reading data from the optical disk, it is not necessary to mount magnetic field applying means such as the magnetic field modulation coil 14 on the slider 13.
[0132]
The optical head device, the control device, and the optical recording / reproducing device combining these in accordance with the present invention are not limited to the above-described embodiments and variations thereof, and the technical idea of the above-described flying head type optical head device is used. It can be applied to take various forms.
[0133]
【The invention's effect】
According to the present invention, it is possible to provide a compact, lightweight and low-cost optical head device. As a result, the optical head device of the present invention is not only applied to a single optical rotating recording medium, but also suitably used for an optical recording / reproducing apparatus in which a plurality of optical rotating recording media are multilayered. be able to. In other words, when the optical head apparatus of the present invention is used, an optical recording / reproducing apparatus in which a plurality of sheets and a plurality of small optical rotating recording media are stacked along the rotation axis to be multilayered can be effectively realized. .
[0134]
Further, according to the present invention, an optical head device having good response in tracking control can be provided.
[0135]
Furthermore, according to the present invention, it is possible to provide a light-weight and small-sized optical head device capable of adjusting the optical path length between the objective lens and the optical unit, although it is a flying head type optical head device.
[0136]
The optical recording / reproducing apparatus of the present invention using the optical head device described above exhibits quick response and high reliability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram of a magneto-optical head device as a first embodiment of an optical head device of the present invention.
FIG. 2 is an enlarged view showing an example of an optical unit mounted on the magneto-optical head device illustrated in FIG. 1;
FIG. 3 is a block diagram of a control device that drives and controls the magneto-optical head device illustrated in FIG. 1;
FIG. 4 is a cross-sectional configuration diagram of a magneto-optical head device as a modification of the first embodiment of the optical head device of the present invention.
FIG. 5 is an enlarged view illustrating the positional relationship among an electromagnetic actuator, an optical unit, a magnetic field modulation coil, and an objective lens as a more specific example of the embodiment illustrated in FIG. 4; is there.
FIG. 6 is a cross-sectional configuration diagram of a magneto-optical head device as a second embodiment of the optical head device of the present invention.
7 is a block diagram of a control device that drives and controls the magneto-optical head device illustrated in FIG. 6. FIG.
FIG. 8 is a cross-sectional configuration diagram of a magneto-optical head device as a modification of the second embodiment of the optical head device of the present invention.
FIG. 9 is a sectional structural view of a magneto-optical head device as a third embodiment of the optical head device of the present invention.
FIG. 10 is a cross-sectional configuration diagram of a magneto-optical head device as a fourth embodiment of the optical head device of the present invention.
FIG. 11 shows an optical recording / reproducing method in which optical rotating recording media are multilayered and data is written to and read from a plurality of optical rotating recording media simultaneously as a fifth embodiment of the present invention. It is a fragmentary perspective view of an apparatus.
FIG. 12 is a block diagram of a magneto-optical recording / reproducing apparatus as a first conventional example.
FIG. 13 is a block diagram of a magneto-optical head as a second prior art.
FIG. 14 is a block diagram of a magneto-optical head as a third prior art.
FIG. 15 is a block diagram of a magneto-optical head as a fourth prior art.
[Explanation of symbols]
1, 1A, 1B ... Magneto-optical head device
11, 11A · · Arm
11A ・ ・ Thick part
11B ... Thin section
12. Suspension (suspending member)
13. Slider
14. Magnetic field modulation coil
15. Objective lens
16. Piezo element
17. Optical part
17A Photodetector (PD) IC
171 ・ ・ Microprism
172..Laser diode (LD)
173. Photodetector
17B ・ ・ Optical unit (package)
18. Axis
19.Voice motor coil
21 .. Electromagnetic actuator
23. Mirror
3. Magneto-optical (MO) disk
31. Top coat
32..Recording film
4. Control device
41 .. Magnet drive part
42..Laser drive section
43..Detection signal processor
44 ・ ・ Tracking servo controller
45 .. Optical path length adjustment section
46 .. Pre-demodulation processor
47 .. Demodulator
48 ・ ・ System controller
49..Modulation section
50..Memory controller
51..RAM
52,52 ・ Interface
100 .. Magneto-optical recording / reproducing apparatus
110 .. Magneto-optical disk
120 .. Magneto-optical pickup
121 .. Board
122 .. Spindle motor
123 ・ ・ Two-axis actuator
124 ..Optical part
125 ・ ・ Overwrite magnetic head
126 .. Screw and screw feed mechanism
127 ... Feed motor
230 .. Control processing section
231 .. Head drive
232 ... Laser drive
233 .. Signal processor
234 .. Servo section
235 .. Pre-demodulation processor
236 .. Demodulator
237 .. System controller
238 .. Modulation section
239 .. Memory controller
240 ... RAM

Claims (15)

An optical head device that optically writes data to and / or reads data from an optical rotary recording medium,
Arm,
An elastic suspension member having one end fixed to the lower surface of the arm;
A slider mounted on the free end of the suspension member and mounted with an objective lens;
An optical unit mounted on the arm so that the optical axis of the optical unit coincides with the optical axis of the objective lens mounted on the slider;
Mounted on the arm and displaced so as to move the optical unit in a direction perpendicular to the surface of the optical rotary recording medium, or in a direction parallel to the surface of the optical rotary recording medium An optical path length adjustment actuator having a piezo element or an electromagnetic actuator that adjusts the optical path length of the objective lens and the optical unit by being displaced so as to move ;
The slider floats from the surface of the optical rotary recording medium according to a change in atmospheric pressure accompanying the rotation of the optical rotary recording medium by a predetermined distance that does not require focus control .
Optical head device. The optical unit is mounted on the free end side of the arm so that the optical axis is oriented in a direction parallel to the surface of the optical rotary recording medium,
The optical path length adjusting actuator is an actuator that displaces the optical unit to move in a direction parallel to the surface of the optical rotary recording medium,
In the vicinity of the position where the optical unit of the arm is mounted, there is provided a deflecting means for directing light in the horizontal direction from the optical unit to the objective lens located at the lower part of the arm,
The optical head device according to claim 1. The optical unit is mounted on the free end side of the arm so that the optical axis is oriented in the horizontal direction,
The optical path length adjusting actuator is an actuator that displaces the optical unit so as to move in a direction orthogonal to the surface of the optical rotary recording medium,
Deflection means for directing light in a direction parallel to the surface of the optical rotary recording medium from the optical unit to the objective lens positioned below the arm, in the vicinity of the position where the optical unit of the arm is mounted. Provided,
The optical head device according to claim 1. The optical unit, the front optical path length adjusting actuator, and the deflecting unit are mounted on the upper surface of the free end side of the arm,
An opening for establishing an optical path between the deflection unit and the objective lens is provided at a lower portion of the arm on which the deflection unit is mounted.
The optical head device according to claim 1 . The optical rotary recording medium is an optical rotary recording medium of a type in which data is written in a magnetic field application state or a magnetic field modulation state,
The objective lens and magnetic application means or magnetic field modulation means are mounted on the slider,
The optical head device according to claim 1. The optical rotary recording medium is an optical rotary recording medium of a method in which data is read in a magnetic field state,
Only the objective lens is mounted on the slider,
The optical head device according to claim 1. An arm driving actuator that drives the arm to move the slider in a track direction of the optical rotary recording medium;
The optical head device according to claim 1. An optical rotary recording medium;
An optical head device for optically writing and / or reading data on the optical rotary recording medium;
An optical recording / reproducing device having a control device for driving the optical head device to write data to the optical rotary recording medium and / or to read data,
The optical head device includes:
Arm,
An elastic suspension member having one end fixed to the lower surface of the arm;
A slider mounted on the free end of the suspension member and mounted with an objective lens;
An optical unit mounted on the arm so that the optical axis of the optical unit coincides with the optical axis of the objective lens mounted on the slider;
Mounted on the arm and displaced so as to move the optical unit in a direction perpendicular to the surface of the optical rotary recording medium, or in a direction parallel to the surface of the optical rotary recording medium An optical path length adjusting actuator having a piezo element or an electromagnetic actuator that adjusts an optical path length between the objective lens and the optical unit by being displaced so as to move, and driving the arm to move the slider to the optical rotation recording An arm drive actuator that moves in the track direction of the medium,
The slider is configured to float from the surface of the optical rotary recording medium according to a change in atmospheric pressure accompanying the rotation of the optical rotary recording medium by a predetermined distance that does not require focus control,
The controller is
Tracking servo control means for controlling the track position by driving the arm drive actuator;
Optical path length adjusting means for driving the optical path length adjusting actuator to adjust the optical path length of the optical system in the optical head device;
Optical recording / reproducing device. The optical unit is mounted on the free end side of the arm so that its optical axis is oriented in the horizontal direction,
The optical path length adjusting actuator is an actuator that displaces the optical unit to move in a direction parallel to the surface of the optical rotary recording medium,
Deflection means for directing light in the horizontal direction from the optical unit to the objective lens positioned below the arm is provided in the vicinity of the position where the optical unit of the arm is mounted;
The optical recording / reproducing apparatus according to claim 8 . The optical unit is mounted on the free end side of the arm so that its optical axis is oriented in a direction parallel to the optical rotary recording medium,
The optical path length adjustment actuator is an actuator that displaces the optical unit so as to move in a direction orthogonal to the surface of the optical rotary recording medium,
Deflection means for directing light from the optical unit to the objective lens positioned below the arm is provided in the vicinity of the position where the optical unit of the arm is mounted;
The optical recording / reproducing apparatus according to claim 8 . The optical unit, the front optical path length adjusting actuator, and the deflecting unit are mounted on the upper surface of the free end side of the arm,
An opening for establishing an optical path between the deflection unit and the objective lens is provided at a lower portion of the arm on which the deflection unit is mounted.
The optical recording / reproducing apparatus according to claim 8 . The optical unit, the front optical path length adjusting actuator, and the deflecting unit are mounted on the upper surface of the free end side of the arm,
An opening for establishing an optical path between the deflection unit and the objective lens is provided at a lower portion of the arm on which the deflection unit is mounted.
The optical recording / reproducing apparatus according to claim 8 . The optical rotary recording medium is an optical rotary recording medium of a type in which data is written in a magnetic field application state or a magnetic field modulation state,
The objective lens and magnetic application means or magnetic field modulation means are mounted on the slider,
The optical recording / reproducing apparatus according to claim 8 . The optical rotary recording medium is an optical rotary recording medium of a method in which data is read in a magnetic field state,
Only the objective lens is mounted on the slider,
The optical recording / reproducing apparatus according to claim 8 . An arm driving actuator that drives the arm to move the slider in a track direction of the optical rotary recording medium;
The optical recording / reproducing apparatus according to claim 8 .

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