JP2003085768A - Optical information recording apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately record a hologram at each information recording position of an information recording area while moving a recording medium having a plurality of information recording areas using a low-power laser light source. . When recording a hologram at each information recording position of an information recording area of an optical information recording medium, the information recording position moving with the movement of the optical information recording medium is set at a predetermined time required for exposure for a predetermined time. It is required that the irradiation positions of the light and the recording reference light follow. Therefore, in the present invention, the servo control in the moving direction of the optical information recording medium is performed by detecting a positional shift between at least one lock-up pit disposed in the information recording area and the optical head, and during the recording of the hologram. The hologram is recorded on the optical information recording medium by continuously irradiating the information recording position with the information light and the recording reference light accurately without causing a positional shift.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
An optical information recording device, an optical information recording method, and an optical information recording medium for recording information at an ultrahigh density by using holography on an optical information recording medium having a servo area and an information recording area, and more specifically, TECHNICAL FIELD The present invention relates to an optical information recording apparatus and an optical information recording method for recording information with high density and high accuracy by aligning an interference fringe pattern by holography with each information recording position of an information recording area by using a low output light beam. ..

[0002]

2. Description of the Related Art Holographic recording in which information is recorded in an optical information recording medium at a super high density by means of a hologram causes information light carrying image information and recording reference light to overlap each other inside the optical information recording medium to cause interference. Writing is performed by generating a fringe pattern and fixing the interference fringe pattern in the optical information recording medium. When reproducing information from the recorded interference fringe pattern, the interference fringe pattern in the optical information recording medium is irradiated with reproduction reference light, and the interference fringe pattern causes diffraction to reproduce image information. There is.

In order to perform ultra-high density optical recording, recently, volume holography in which an interference fringe pattern of information light and recording reference light is three-dimensionally generated in an optical information recording medium to perform information recording, In particular, the development of digital volume holography has attracted attention. Volume holography actively utilizes the thickness direction of the optical information recording medium,
This is a method of writing an interference fringe pattern by holography in a recording layer of an optical information recording medium three-dimensionally, that is, three-dimensionally.
There is a feature that the thickness of the recording layer is increased and the interference fringe pattern is three-dimensionally recorded to improve the diffraction efficiency, and the multiple recording is performed to dramatically increase the information recording capacity.

Further, the digital volume holography, in principle, employs the same optical information recording medium and recording method as the volume holography, but the image information recorded on the optical information recording medium is binarized by computer processing. Then, it is digitally patterned and then recorded using holography. Therefore, in digital volume holography, analog image information is also binarized and converted into digital pattern information, and then recorded as digital image information on an optical information recording medium by using holography.

A recording / reproducing system based on such a conventional volume holography is applied to recording / reproducing on a moving (rotating) optical information recording medium, and a plurality of interference fringe patterns are sequentially formed on an information recording area of the optical information recording medium. It is possible to dramatically increase the recording density by performing multiple recording. FIG. 16 shows an example of such an optical information recording medium, and an information recording area 7 is provided between the address servo areas 6 adjacent to each other in the circumferential direction of the optical information recording medium 1. In the address servo area 6, information for performing focus servo and tracking servo and address information for the information recording area 7 are recorded in advance by embossed pits. In the volume holographic recording, the change in the interference fringe pattern in the thickness direction of the recording layer of the information recording area 7 of the optical information recording medium is positively utilized, and the interference fringes are three-dimensionally formed on the recording layer of the optical information recording medium 1. This is a method of writing a pattern, and is characterized in that the diffraction efficiency can be increased by increasing the thickness, and the recording capacity can be dramatically increased by performing multiple recording.

An apparatus and method for recording and reproducing information on an optical information recording medium by volume holography is disclosed in International Publication No. WO99 / 44195. In order to understand the present invention, a configuration of a recording / reproducing apparatus using volume holography described in the publication will be briefly described. FIG. 17 shows an example of an optical information recording medium 1 to which the present invention is applied. It is an outline,
The optical information recording medium 1 is provided with a hologram recording layer 3, a reflection film 5 and a substrate 4 on a circular transparent substrate 2, and a plurality of address servos are provided in a radial direction on a boundary surface between the hologram recording layer 3 and the substrate 4. The areas 6 are arranged at predetermined angular intervals, and an information recording area 7 is provided between the address / servo areas 6 adjacent in the circumferential direction. In the address / servo area 6, information for performing focus / servo control and tracking / servo control and address information for the information recording area 7 are recorded in advance by embossed pits. As information for performing tracking / servo control, for example, wobble pits can be used.

The specific configuration of the optical information recording medium 1 is such that the transparent substrate 2 has an appropriate thickness of, for example, 0.6 mm or less, and the hologram recording layer 3 has an appropriate thickness of, for example, 10 μm or more. Have The hologram recording layer 3 is formed of a hologram recording material whose optical properties such as a refractive index, a dielectric constant, and a reflectance change according to the intensity of the laser beam when irradiated with the laser beam for a predetermined time. ) Photopolymers
HRF-600 (product name) or the like is used.

One example of recording on the hologram recording layer by volume holography is the transparent substrate 2 side so that the information light carrying the information to be recorded and the recording reference light produce interference fringes in the thickness direction in the hologram recording layer. Information is recorded as a three-dimensional hologram by simultaneously irradiating the hologram recording layer for a predetermined time to stereoscopically fix the interference fringe pattern in the hologram recording layer.

That is, the volume holography positively utilizes the change of the interference fringe pattern in the thickness direction of the hologram recording layer of the optical information recording medium to make a three-dimensional interference fringe on the hologram recording layer of the optical information recording medium. This is a method of writing a pattern, and is characterized in that the diffraction efficiency can be increased by increasing the thickness, and the recording capacity can be dramatically increased by performing multiple recording.

In the digital volume holography, image information is converted into binary data by the same optical information recording medium and recording method as in volume holography, and recorded as a digital interference fringe pattern on the optical information recording medium. Then, it is a computer-oriented hologram recording system in which an interference fringe pattern of digital image information is stereoscopically recorded on a recording layer of an optical information recording medium.

According to this digital volume holography, even analog image information such as a picture is once converted into binary information, then developed into digital pattern information and recorded as image information. During reproduction, the digital pattern information is read and decoded to restore the original analog image information for display. According to this hologram recording method, the binarized data is coded at the time of recording and an error correction code is added, or differential detection is performed even if the signal-to-noise ratio (SN ratio) is slightly bad during reproduction. , It becomes possible to reproduce the original information extremely faithfully.

[0012]

By the way, in a general recording apparatus for optically recording information on a disk-shaped optical information recording medium, an optical beam for information recording is applied to a rotating optical information recording medium. It is equipped with an optical head for irradiation. In such a recording apparatus, while rotating the optical information recording medium, the optical head irradiates the optical information recording medium with a light beam for information recording so that information is recorded on the optical information recording medium. Has become. Further, in such a recording apparatus, a semiconductor laser is generally used as a light source for generating a light beam for recording information.

Also in holographic recording, as in the case of the general optical recording apparatus as described above, the optical information recording medium is irradiated with the information light and the recording reference light while rotating the optical information recording medium. Then, information is sequentially recorded as holograms at predetermined information recording positions in a plurality of information recording areas on the optical information recording medium. Also in recording using such holography, it is desirable to use a practical semiconductor laser as a light source for the information light and the recording reference light, as in a general optical recording apparatus.

That is, a currently used hologram photosensitive material is used for the recording layer of an optical information recording medium for holographic recording, and while the optical information recording medium is rotated, information light and recording are performed by a semiconductor laser beam. When irradiating the optical reference recording light onto the optical information recording medium to record the interference fringe pattern on the recording layer, the energy of the semiconductor laser beam causes a predetermined information recording position in the information recording area of the moving optical information recording medium. However, there is a problem that the exposure energy is insufficient for instantaneously recording the interference fringe pattern, and satisfactory recording cannot be performed. Therefore, in order to give sufficient exposure energy to the recording layer at the information recording position in the information recording area, it is conceivable to use a laser beam having a large output or to extend the exposure time and integrate the exposure amount.

However, in the case of the former, the equipment becomes large-scaled and the cost of the equipment investment increases, and in the case of the latter, the information recording position of the information recording area during the exposure time by the laser beam is the exposure position. It becomes impossible to fix a sharp interference fringe pattern on the recording layer by deviating from it, and the accuracy of information is lowered. That is, if information is recorded as a hologram on the recording layer of the optical information recording medium by using a high-output light source such as a pulse laser instead of a semiconductor laser as the light source, the maximum output is 500 W and 20 ns.
Although information can be recorded with the exposure time of, it is not practical to use such a high-power pulse laser.

On the other hand, if information is to be recorded as a hologram on the recording layer of the optical information recording medium by a semiconductor laser having a maximum output of 20 mW, it is 200 μse for the integration of the exposure amount.
Requires an exposure time of c. However, if an attempt is made to record a hologram at the information recording position of the rotating optical information recording medium by a laser beam emitted from a semiconductor laser beam source that does not move in the moving direction of the optical information recording medium, the optical information recording medium will be Since it moves at a peripheral velocity of s, the information recording position of the information recording area is 400 μm during the exposure time from the initial irradiation position of the semiconductor laser beam.
Also moves, and the information cannot be recorded at the information recording position of the rotating optical information recording medium as a hologram by the low output semiconductor laser beam.

An object of the present invention is to provide a technique for solving such a problem at the time of recording, by using a laser beam from a low output laser beam source such as a semiconductor laser,
By providing a means capable of accurately irradiating a laser beam until a sufficient amount of irradiation for exposure is provided at a predetermined information recording position of an information recording area of a moving optical information recording medium, information by a hologram is recorded. To provide an optical information recording apparatus and method capable of recording on a recording layer at a predetermined information recording position, and to provide an optical information recording medium in which information is recorded at high density as a hologram by the apparatus and method. It is in.

[0018]

A recording apparatus embodying the present invention records a hologram at each information recording position in an information recording area of an optical information recording medium having a plurality of address / servo areas and information recording areas. An optical information recording device for recording information on an optical information recording medium such that a hologram is formed at each information recording position of the optical information recording medium by an interference fringe pattern of the information light and the recording reference light. Irradiation means for irradiating light and recording reference light, optical information recording medium moving means for moving the optical information recording medium, each information recording position of the moving optical information recording medium, and the information light and recording reference light Positional deviation detecting means provided with at least one positioning information (lock-up pit) for detecting positional deviation in the moving direction of the optical information recording medium from the irradiation position, and each information recording position An irradiation position moving means for moving the irradiation means back and forth in the moving direction of the optical information recording medium based on the output of the positional deviation detection means so that the irradiation position accurately follows the predetermined time. is there.

According to the present invention, the optical information recording medium is moved by the optical information recording medium moving means, and the optical information recording medium is irradiated with the information light and the recording reference light by the irradiation means and the irradiation position. By the moving means, the irradiation positions of the information light and the recording reference light are moved so that the irradiation positions of the information light and the recording reference light accurately follow the respective information recording positions of the moving information recording area. , Thereby, the information recording position of the information recording area of the optical information recording medium is continuously irradiated with the information light and the recording reference light for a sufficient time for exposure for recording without causing positional deviation, and information by the hologram is recorded. Will be recorded.

According to the present invention, in the information recording area of the optical information recording medium, in order to make the irradiation positions of the information light and the recording reference light follow each other, the respective information recording positions are moved. At least one lock-up pit is provided in the area, and the optical information recording device has means for detecting a positional deviation between each lock-up pit and the irradiation position of the position detection light beam in the moving direction of the optical information recording medium. Is equipped with.

In one example of the optical information recording apparatus for carrying out the present invention, the light beam irradiating means coaxially supplies the information light and the recording reference light to the information recording layer of the optical information recording medium from the same surface side. Further, the irradiation is performed while converging the optical information recording medium so that the diameter becomes the smallest at different positions in the thickness direction.

The recording method embodying the present invention is an optical information recording method for recording information by holograms at a plurality of information recording positions of each information recording area in an optical information recording medium having a plurality of address / servo areas and information recording areas. A method for moving an optical information recording medium, wherein information is recorded at each information recording position of an information recording area by an interference fringe pattern of the information light and a recording reference light. The optical information recording medium is moved so that each information recording position in the moving information recording area is irradiated with the information light and the recording reference light and the irradiation position of the information light and the recording reference light does not deviate by a predetermined time. The irradiation means is made to follow and move.

In the present invention, the moving optical information recording medium is irradiated with the information light and the recording reference light, and the irradiation position of the information light and the recording reference light is set at each information recording position of the moving information recording area. The irradiation positions of the information light and the recording reference light are moved so that they follow each other without shifting for a predetermined time. Accordingly, while the hologram is recorded at one information recording position in the information recording area, there is no displacement between the information recording position and the irradiation position of the information light and the recording reference light, and therefore the information Since one information recording position in the recording area can be continuously exposed by the information light and the recording reference light for a sufficient time for recording the hologram,
Even if a low-power semiconductor laser beam source is adopted, it is possible to record information on the optical information recording medium by means of a hologram.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. As shown in FIG. 1 and FIG. 2 which is a partially enlarged view of the optical information recording medium of the present invention, a disc-shaped optical information recording medium 1 and a plurality of recording tracks T on its recording surface are shown.
Shows a part of one track in R, each track TR
Is provided with a plurality of address / servo areas 6 provided at equal intervals and an information recording area 7 between adjacent address / servo areas 6 in the moving direction of the optical information recording medium.

In each address / servo area 6, basic clock information serving as a timing reference for various operations in the optical information recording / reproducing apparatus, information for performing focus servo by the sampled servo system, sampled servo Information for performing tracking servo by the method and address information for the information recording area are recorded in advance by embossed pits or the like.

The basic clock information recorded in the address servo area is information for providing the basic clock of the optical information recording / reproducing apparatus, and the information for performing the focus servo and the information for performing the tracking servo are: Information for focusing the information light, the recording reference light and the reproducing reference light for each subsequent information recording area 7 and for accurately tracking the irradiation position on the track, once in the address servo area 6. When focus servo and tracking servo are performed, the state is maintained until the next address servo area 6 via the information recording area.

Further, in the address / servo area 6, address information for identifying each subsequent information recording area 7 is recorded, and in recording a hologram, it is recorded in the address / servo area. The information is used as positioning information for aligning the irradiation position of the information light, the recording reference light and the reproduction reference light with respect to the information recording position of each information recording area 7, and the optical information is used. The recording / reproducing apparatus detects the address information recorded in the address / servo area 6 to identify each information recording area 7, and detects the information recorded in the address / servo area 6 to detect each information recording area. The irradiation positions of the information light, the recording reference light and the reproducing reference light in No. 7 were aligned. Therefore, even when the irradiation positions of the information light, the recording reference light and the reproducing reference light with respect to the information recording position of each information recording area 7 are aligned, the servo control state in the address / servo area passes through the information recording area. Next address
It was maintained up to the servo area 6.

1 and 2, the optical information recording medium embodying the present invention is characterized in that at least one lock-up pit 8 is previously embossed in the information recording area 7 of each track TR on the recording surface thereof. Recorded by pits,
Even when the optical head is scanning the information recording area 7, the positional deviation between the lock-up pit 8 and the irradiation position of the tracking servo light beam is detected, and the information recording position 7 ′ of each information recording area 7 is detected. The position of the information light for tracking the information recording position 7 ', the reference light for recording, and the irradiation position of the reference light for reproduction can be adjusted by the tracking servo control.

At least one lock-up pit 8 is provided corresponding to each information recording position 7 ', and the tracking servo is always performed during hologram recording at the information recording position 7', so that the information recording position It is possible to record a hologram of extremely high quality without any positional deviation between 7'and the irradiation position of the laser beam for hologram formation. Of course, the irradiation position of the laser beam for hologram formation irradiated on the optical information recording medium 7 is displaced by a predetermined distance in the circumferential direction from the lock-up pit every time the recording of the hologram is completed at each information recording position 7 '. By irradiating it. It is also possible to perform tracking servo for a plurality of information recording positions 7'by one lock-up pit.

That is, according to the present invention, when recording the information by the hologram in the information recording position 7'of the information recording area 7 of the optical information recording medium 1 by using the low output semiconductor laser beam, for example, in FIG. In order to record a hologram by the interference of the information light and the recording reference light at each information recording position 7 ′ of the information recording area 7 of the optical information recording medium that moves (rotates) in the direction indicated by the symbol R, The relative positions of the information recording position 7 ′ of the optical information recording medium 1 and the irradiation positions of the information light and the recording reference light are displaced from each other so that the exposure amount by the forming laser beam is integrated to obtain a sufficient exposure amount. It is necessary to continue to maintain exactly so that there is no.

However, in the conventional optical recording method, the position control for detecting the information recorded in the address / servo area and adjusting the beam irradiation position by the optical head to the information recording position in the subsequent information recording area 7 is performed. Although it has been performed, the plurality of information recording positions 7 ′ in the information recording area 7 are accurately aligned with the irradiation positions of the information light and the recording reference light, and the predetermined time required for the sequential exposure is followed. At the very least, the position control means for sequentially recording the information by the hologram at each information recording position 7 ′ of the information recording area 7 of the optical information recording medium is insufficient, and therefore, in the present invention, the moving optical information recording is performed. An index (especially for detecting a relative positional deviation in the moving direction of the optical information recording medium between each information recording position 7 ′ in the information recording area 7 of the medium and the irradiation positions of the information light and the recording reference light. Click up pit) is provided,
The tracking servo control in the moving direction of the optical information recording medium with respect to the optical head is always performed in the information recording area even during the recording of the hologram based on the position shift signal detected by the index portion.

That is, according to the present invention, it is at least as shown in FIG. 2 that the tracking servo control of the movement of the optical head in the moving direction of the optical information recording medium 1 is always accurately performed even in the information recording area 7. Since this is possible by providing one lock-up pit 8, the irradiation position of the information light and the recording reference light can follow each information recording position 7 ′ of the information recording area 7 without displacement, and the hologram can be displayed. It is possible to secure the exposure time required for recording.

More specifically, in the present invention, the lock-up pit 8 provided as an index for performing the tracking servo control by the optical head has a wavelength λ ₁ different from the wavelength λ ₂ of the laser beam for hologram formation. By irradiating with the laser beam for servo, even if the irradiation positions of both laser beams overlap on the optical recording medium, interference can be avoided, and the information recording position 7'of the optical information recording medium 1 by the lock-up pit And a tracking servo circuit described later for detecting the positional deviation detection signal in the moving direction of the optical information recording medium 1 without hindering the relative positional deviation between the irradiation position of the hologram forming laser beam and the irradiation position. To accurately track the irradiation positions of the information light and the recording reference light on the information recording position 7'of the optical information recording medium 1 during the recording of the hologram. It is characterized by performing servo control.

According to the present invention, each information recording position 7'in the information recording area 7 is irradiated with the information light and the recording reference light, that is, the laser beam for hologram formation accurately for a predetermined time, so that even if Even with the laser beam from the output semiconductor laser beam source, the hologram can be surely recorded at each information recording position 7 ′ of the information recording area 7 of the optical information recording medium 1. That is, according to the present invention, during recording of the hologram, there is no deviation between each information recording position 7 ′ of the information recording area 7 and the irradiation position of the information light and the recording reference light, and the information recording area It is possible to continue irradiating the information light and the recording reference light until the light quantity (integral value) sufficient to record the hologram at the information recording position 7'of No. 7 is reached.

FIG. 3 schematically shows an optical information recording / reproducing apparatus 10 for carrying out the present invention. The optical information recording / reproducing apparatus 10 includes a spindle 81 to which the optical information recording medium 1 is attached and the spindle 81. And a spindle servo circuit 83 for controlling the spindle motor 82 so as to keep the number of rotations of the optical information recording medium 1 at a predetermined value. The optical information recording / reproducing apparatus 10 further irradiates the optical information recording medium 1 with the information light and the recording reference light to record a hologram, and at the same time, reproduces the optical information recording medium 1 on which the hologram is recorded for reference. An optical head 40 for irradiating light, detecting reproduction light, and reproducing the original information from the hologram recorded in the optical information recording medium 1, and the optical head 40.
And a driving device 84 for driving the same in the radial direction.

The optical information recording / reproducing apparatus 10 includes an optical head 40.
Focus error signal FE, tracking error signal TE, tracking error signal CE, and reproduction signal R from the output signal of
A detection circuit 85 for detecting F, and this detection circuit 85
Based on the focus error signal FE detected by the controller and a command from the controller 90, while the optical head 40 passes through the address / servo area, the optical head main body, which will be described later, is moved in a direction perpendicular to the surface of the optical information recording medium 1. Focus servo circuit 86 for moving focus servo control
Based on the tracking error signal TE detected by the detection circuit 85 and the command from the controller 90,
While the optical head 40 passes through the address servo area, it is detected by a detection servo 85 and a tracking servo circuit 87 that performs tracking servo control by moving the optical head body in the radial direction of the optical information recording medium 1. Based on the tracking error signal CE and the command from the controller 90, while the optical head 40 passes through the information recording area, the optical head main body is moved in the moving direction of the optical information recording medium 1 to record the information in the information recording area. Based on a tracking servo circuit 95 that performs tracking servo control so that the irradiation positions of the information light and the recording reference light follow the position for a predetermined time without displacement, and a tracking error signal TE and a command from the controller 90, the driving device 84. And a slide for performing servo control to move the optical head 40 in the radial direction of the optical information recording medium 1 by controlling A servo circuit 88, the controller 9
Based on a command from 0, the optical head 40 has a tracking control circuit for tracking the optical head to a desired recording position while passing through the address servo area.

The optical information recording / reproducing apparatus 10 also decodes output data of a CCD array, which will be described later, in the optical head 40 and records the data at each information recording position 7'in the information recording area 7 of the optical information recording medium 1. A signal processing circuit 89 for reproducing a hologram, reproducing a basic clock from a reproduction signal RF from the detection circuit 85, and determining an address,
A controller 90 that controls the overall operation of the optical information recording / reproducing apparatus 10 and an operation unit 91 that gives various instructions to the controller 90 are provided.

Further, the optical information recording / reproducing apparatus 10 uses the optical information recording medium 1 based on the output signal of the signal processing circuit 89.
And an optical head main body in a direction in which the inclination of the optical head main body with respect to the surface of the optical information recording medium 1 changes based on an output signal of the inclination detection circuit 92. An inclination correction circuit 93 is provided which corrects the relative inclination between the optical information recording medium 1 and the optical head main body by changing the position of the main body.

In the optical information recording / reproducing apparatus 10, during recording of the hologram, the optical head 40 is moved for a predetermined time by moving the optical head main body in a direction substantially along the track while the optical head 40 passes through the address / servo area. A tracking control circuit 94 for controlling the irradiation positions of the information light and the recording reference light so that the irradiation positions of the information light and the recording reference light follow one information recording position 7 ′ of the information recording area 7.
However, in the present invention, in order to perform the tracking servo control so that the irradiation positions of the information light and the recording reference light track the information recording position 7 ′ more precisely and accurately, the detection roundabout 85 is used. Each information recording position 7'in the information recording area 7
A positional deviation in the moving direction of the optical information recording medium 1 between the irradiation positions of the information light and the recording reference light is detected by irradiating the lock-up pit with a laser beam for tracking servo as a tracking error signal CE, and the tracking is performed. A tracking servo circuit 95 is provided for performing tracking servo (Asking Servo) by moving the optical head main body in the moving direction of the optical information recording medium 1 even within the information recording area based on the error signal CE. .

The controller 90 inputs the basic clock and address information output from the signal processing circuit 89, and also the optical head 40, the spindle servo circuit 83, the slide servo circuit 88, the focus servo circuit, and the tracking servo circuit. The tracking servo circuit and the tracking control circuit 94 are controlled. The basic clock output from the signal processing circuit 89 is input to the spindle servo circuit 83. The controller 90 is C
The controller has a PU (central processing unit), a ROM (read only memory) and a RAM (random access memory), and the CPU executes the program stored in the ROM by using the RAM as a work area. 90 functions are realized.

Next, an example of the optical head 40 used in the optical information recording / reproducing apparatus for carrying out the present invention will be described with reference to FIG. 4 showing a plan view of the optical head 40. The optical head 40 has an optical head main body 41 that records information on the optical information recording medium 1 and reproduces information from the optical information recording medium 1. The optical head main body 41 is an objective that faces the optical information recording medium 1. It has a lens 11. Optical head body 4
Elastic arm fixing portions 140a and 140b are provided at both ends in the tangential direction of the track in FIG.
Is provided. This elastic arm fixing part 140a, 1
40b includes elastic arms 149 formed of elastic members such as rubber, leaf springs, coil springs, and wires.
One end of is fixed. The other end of each elastic arm 149 is fixed to the arm support 150. The arm supporting part 150 is attached to a piezoelectric actuator 170 capable of moving the arm supporting part 150 in the radial direction (vertical direction in FIG. 4) of the optical information recording medium 1 within a predetermined range.

Coils 151 and 152 for focus / servo and tilt adjustment and coils 155 and 156 for tracking irradiation position are attached to one end of the optical head main body 41 in the radial direction of the optical information recording medium 1. ing. Similarly, coils 153 and 154 for focus / servo and tilt adjustment and coils 157 and 158 for tracking irradiation positions are attached to the other end of the optical head main body 41 in the radial direction of the optical information recording medium 1. ing.

The optical head 40 further includes coils 1
51, 152, 153, 154 and magnets 161, 162, 163, 164 provided so as to penetrate the coil 1
55, 156 magnets 165 arranged at positions facing each other
And a magnet 166 arranged at a position facing the coils 157 and 158.

In the optical head 40, the coils 151 to 1 are used.
54 and the magnets 161 to 164, in the direction perpendicular to the surface of the optical information recording medium 1 (direction perpendicular to the paper surface in FIG. 4) and the direction in which the inclination of the optical head main body 41 with respect to the surface of the optical information recording medium 1 changes. The position of the optical head body 41 can be changed. Further, in the optical head 40,
By the piezoelectric actuator 170, the optical information recording medium 1
The position of the optical head main body 41 can be changed in the radial direction of. In the optical head 40, the elastic arm 14
9, the coils 155 to 158 and the magnets 165 and 166 allow the optical head body 4 to move in the moving direction of the optical information recording medium.
The position of 1 can be changed. Elastic arm 14
9, coils 155 to 158 and magnets 165 and 166
Corresponds to the irradiation position moving means in the present invention.

The coils 151 to 154 are driven by the focus / servo circuit 86 and the tilt correction circuit 93 in FIG. 3, and the coils 155 to 158 are driven by the follow-up control circuit 94 in FIG. . Further, in the present invention, the additional coil 160 is provided along with the coils 155 to 158, and the additional coil 160 is supplied with the output signal of the tracking servo circuit 95 to which the tracking error signal CE detected by the detection circuit 85 is supplied to add the additional coil 160. By the coil 160 and the magnets 165 and 166, precise tracking servo by the optical head main body 41 is performed along the moving direction of the optical information recording medium 1, that is, along the track TR. The piezoelectric actuator 170 capable of changing the position of the optical head body 41 in the radial direction of the optical information recording medium 1 is
It is driven by the output of the tracking servo circuit 87 in FIG.

In the optical head 40 shown in FIG. 4, a piezoelectric actuator 170 is used to change the position of the optical head main body 41 in the radial direction of the optical information recording medium 1 and faces the coils 155, 156 and the additional coil 160. Magnet 165 arranged at a position where the magnet 166 is arranged, and a magnet 166 arranged at a position facing the coils 157, 158 and the additional coil 160.
Although the case where the position of the optical head main body 41 is changed in the moving direction of the optical information recording medium is shown by, the relative position obtained by rotating the optical head 40 shown in FIG. 4 by 90 ° is shown in FIG. The optical head 40 is arranged on the optical actuator 40, and the piezoelectric actuator 1
70, and a magnet 165 arranged at a position facing the coils 155 and 156 without adding the additional coil 160.
And the magnet 166 arranged at a position facing the coils 157 and 158, the position can be changed in the radial direction of the optical information recording medium.

In the optical head 40 shown in FIG. 5, the position change of the optical head main body 41 by the piezoelectric actuator has a faster response speed than the position change of the head main body 41 by the combination of the coil and the magnet. Therefore, the arrangement of the optical head shown in FIG. 5 is more preferable than the arrangement of FIG. 4 for the present invention.

Next, with reference to FIG. 6, an example of the optical system 11 of the optical head for recording / reproducing according to the present invention will be described. The optical information recording medium 1 according to the present invention is
It is composed of a disk-shaped transparent substrate 2 made of polycarbonate or the like, an information recording layer 3 laminated in order from the transparent substrate 2, a transparent substrate 2 ', and a substrate 4 having a reflective film 5. On the boundary surface between the information recording layer 3 and the substrate 4, a plurality of address / servo areas 6 aligned in the radial direction are preliminarily provided as embossed pits at predetermined angular intervals. A sector-shaped information recording area 7 is provided, and holograms are sequentially recorded at a plurality of information recording positions in the information recording area 7. According to the present invention,
At least one lock-up pit for tracking servo control, which is a feature of the present invention, is provided in each information recording area 7, and in one example, corresponds to each information recording position 7 ′ in the radial direction of the optical information recording medium. It is provided as an embossed pit in advance so as to be aligned (see FIGS. 1 and 2).

Information recording layer 3 laminated on transparent substrate 2
Is a layer in which a hologram is recorded three-dimensionally, and is formed of a material whose optical properties such as refractive index, dielectric constant, and reflectance change according to the intensity of the laser beam when the laser beam is irradiated. A transparent substrate 2'is provided on the information recording layer 3, and a substrate 4 made of, for example, a plastic in which an aluminum film is formed as a reflective film 5 is provided on the transparent substrate 2 '. .

To record a hologram on the optical information recording medium 1, a divergent laser beam emitted from a laser source 25 is converged by a lens 24 to form a laser beam, and this laser beam is split into two beams using a half mirror. It is divided into laser beams, one of which is used as information light modulated by recording information, and the other of which is used as recording reference light for forming an interference pattern. That is, in recording the hologram, the information light and the recording reference light are recorded on the optical information recording medium 1 so that a three-dimensional interference fringe pattern is formed in the information recording layer 3 by the interference between the information light and the recording reference light. This is performed by irradiating the information recording layer 3 for a predetermined time. In order to irradiate one of the information recording positions on the information recording layer 3 of the optical information recording medium 1 with the information light and the recording reference light for a predetermined time, the movement of the optical information recording medium 1 and the irradiation position of the optical head are changed. The movement and the movement are synchronized for a predetermined time.

That is, it is necessary to move in synchronization with the time required for exposure accurately. Therefore, in the present invention, by providing at least one lock-up pit 8 in the information recording area and irradiating the lock-up pit 8 with a tracking laser beam having a wavelength different from the wavelength of the laser beam for hologram recording, The positional deviation between the information recording position and the irradiation position of the information light and the recording reference light is detected, and at the time of recording the hologram, the information recording position 7'of the information recording area 7 '
Tracking servo control for accurately aligning and moving the irradiation position of the information light and the recording reference light for a predetermined time is performed. Reproduction of the recorded hologram is performed by irradiating the information recording layer 3 with reproduction reference light in place of the recording reference light for forming the interference pattern.

Further, an example of the optical system shown in FIG. 6 is a schematic view showing the principle of the optical part of the optical head used in the optical information recording / reproducing apparatus for carrying out the present invention, and the recording / reproducing optical system in this example. That is, the optical head 11 includes the objective lens 12 facing the optical information recording medium 1 and the objective lens 1
An actuator 13 for moving the optical information recording medium 1 in the thickness direction and the radial direction of the optical information recording medium 1, and on the light source side of the objective lens 12, a two-divided optical rotation plate 14 and a prism block 15 are arranged in this order from the objective lens. The optical rotation plate 14 is composed of an optical rotation plate 14L arranged on the left side portion of the optical axis and an optical rotation plate 14R arranged on the right side portion of the optical axis. The optical rotation plate 14L changes the polarization direction of the laser beam to +45.
The optical rotation plate 14R rotates the polarization direction of the laser beam by −45 °. The prism block 15 has a half mirror 15a and a total reflection mirror 15b in order from the side of the two-part optical rotation plate 14. Both the half mirror 15a and the total reflection mirror 15b are arranged such that their normal directions are inclined by 45 ° in the same direction with respect to the optical axis of the objective lens 12.

Another prism block 19 is further arranged in parallel to the side of the prism block 15, and the total reflection mirror 19a of the prism block 19 is arranged in parallel so as to face the half mirror 15a of the prism block 15. To be done. Similarly, the half mirror 19b of the prism block 19 is arranged in parallel to face the total reflection mirror 15b of the prism block 15. Prism block 1
A prism block 23 having a half mirror 23a and a prism block 30 having a half mirror 30a are further arranged on the side of 9 respectively.

Half mirror 15 of prism block 15
The convex lens 16 and the light modulator 17 are arranged between a and the total reflection mirror 19a of the prism block 19, and the light is provided between the total reflection mirror 15b of the prism block 15 and the half mirror 19b of the prism block 19. Modulator 18
Are arranged. The optical modulator 17 has a large number of minute sections arranged in a lattice, and is configured to change the phase of the passing laser beam for each minute section and spatially modulate the phase of the passing laser beam. The reference light is generated when the hologram is formed or the hologram is read, and can be easily realized by using a liquid crystal element.

On the other hand, the optical modulator 18 functions as an information light generating means, and its structure is made up of a large number of minute sections arranged in a grid like the optical modulator 17, and a laser beam is supplied to each minute section. By selecting the passing state and the blocking state according to the information to be recorded, it is possible to spatially modulate the intensity of the laser beam and generate information light carrying information. Like the optical modulator 17, a liquid crystal element can be used for the optical modulator 18.

The light source of the optical head 11 converges the coherent divergent laser light from the laser light source 25 for hologram recording / reproducing, the laser light source 33 for tracking servo, and the laser light sources 25, 33 into a parallel light beam to form a laser beam. The half mirrors 23a and 30a provided with the collimator lenses 24 and 32, respectively, and provided on the prism blocks 23 and 30, respectively, are inclined by 45 ° with respect to the optical axes of the collimator lenses 24 and 32 in the normal direction. . Laser light source 2 that transmits through the half mirrors 23a and 30a
A part of the projected light from 5, 33 is generated by the photo detector 2.
The outputs of the photodetectors 26, 31 are directed to 6, 31 and automatically adjust the light output from the light sources 25, 33.

The return beam from the optical information recording medium 1 is reflected by the half mirror 23a, passes through the convex lens 27 and the cylindrical lens 28 provided on the side opposite to the photodetector 26, and then is divided into four photodetectors 29.
And the focus error signal FE and the tracking error signal TE are respectively detected and the reproduction signal RF is derived while the optical head passes through the address servo area. The detected focus error signal FE is used for focus / servo control of the optical head, and the tracking error signal TE is used for performing tracking / servo control of the optical head.

According to the present invention, when the optical head passes through the information recording area, the tracking error signal CE is detected to perform the tracking servo control of the optical head. The irradiation position of can be moved by displacing the emission position of the laser light source for tracking servo from the optical axis of the collimator lens 32 according to the recording mode of the hologram. Therefore, the laser beam for tracking servo irradiates the lock-up pit to detect the tracking error signal CE, and while the tracking servo control is performed, the information recording position is irradiated with the laser beam for hologram recording to record the hologram. It is configured to do.

Further, according to the present invention, it is possible to implement the tracking servo control for one or a plurality of information recording positions by one lock-up pit, and to implement the tracking servo control for a plurality of information recording positions. Every time the recording of the hologram at each information recording position 7'is completed, the position of the laser light source for tracking servo is set to the collimator lens 32 according to the distance between the lock-up pit and the recording position for newly recording the hologram. It may be configured so as to be sequentially displaced from the optical axis of.

During servo control during information reproduction, all minute sections of the optical modulator 18 are set in the light passing state, and the laser beam from the laser light source 25 for hologram recording / reproduction is set to a low output for reproduction. The controller 90 controls the reproduction signal R
The timing at which the laser beam projected on the optical information recording medium passes through the address / servo area 6 is predicted based on the basic clock reproduced from F, and while the laser beam passes through the address / servo area 6, Settings for servo control are made.

The path of the laser beam passing through the inside of the optical head will be described. In the configuration of FIG. 6, the half mirror 30a of the beam splitter 30 transmits the laser beam of the wavelength emitted from the laser light source 25, and the laser light source 33. For the laser beam of the wavelength emitted from, it is desirable to form it by a dichroic mirror that functions as a half mirror. The divergent laser light emitted from the laser light source 25 is converged into a parallel laser beam by the collimator lens 24, enters the beam splitter 30, passes through the half mirror 30a, and passes through the beam splitter 2
It is incident on 3. The half mirror 23a transmits a part of the light amount and reflects a part thereof.

The light reflected by the half mirror 23a is received by the photodetector 26, and the light amount of the light source is automatically adjusted. The laser beam transmitted through the half mirror 23a is incident on the prism block 19, and a part of the light amount is transmitted through the half mirror 19b. The laser beam that has passed through the half mirror 19b passes through the spatial light modulator 18, is totally reflected by the total reflection mirror 15b of the prism block 15, then passes through the half mirror 15a, and further passes through the split optical plate 14. Then, the information recording medium 1 is irradiated by the objective lens 12 so as to converge on the boundary surface between the transparent substrate 2 ′ and the substrate 4 in contact with the hologram recording layer 3 in the optical information recording medium 1. This irradiated laser beam is
The light is reflected by the reflection film 5 of the optical information recording medium 1, modulated by the embossing bits in the address servo area 6, and returned to the objective lens 12 side.

The returning laser beam reflected by the reflecting film 5 of the optical information recording medium 1 is collimated by the objective lens 12, passes through the two-divided optical rotatory plate 14 again, and is incident on the prism block 15 again. Partially passes through the half mirror 15a. The returning laser beam that has passed through the half mirror 15 a is reflected by the total reflection mirror 15 b, passes through the spatial light modulator 18, and is reflected by the prism block 19.
Incident on. Part of the laser beam incident on the prism block 19 passes through the half mirror 19b. The returning laser beam that has passed through the half mirror 19b is incident on the beam splitter 23 again, a part of the light amount is reflected by the half mirror 23a, passes through the convex lens 27 and the cylindrical lens 28 in order, and then is separated by the four-division photodetector 29. The intensity thereof is detected and calculated by a detection circuit described later to output an intended error signal from the detection circuit.

At the time of tracking servo control at the time of recording information, all the minute sections of the optical modulator 17 are substantially set to the light blocking state, and all the minute sections of the optical modulator 18 are set to the light passing state, so that the laser light source 33 emits light. The laser beam is reflected by the half mirror 30a, passes through the optical modulator 18, and is reflected by the total reflection mirror 15b. The objective lens 12 irradiates the lock-up pit 8 provided at the interface between the hologram recording layer 3 and the substrate 4. . By the irradiation on the lock-up pit 8, the positional deviation between the irradiation spot and the lock-up pit,
That is, since the tracking error signal CE is detected and precise tracking servo control can be performed based on the detected tracking error signal CE, in the present invention, the hologram recording position of the optical information recording medium and the hologram forming laser beam. The irradiation position can be maintained by performing tracking servo control so as not to cause a positional shift during the time required for recording the hologram, and therefore even if a low-power laser light source such as a semiconductor laser is adopted, It becomes possible to accurately write the hologram on the optical information recording medium.

During tracking servo control during information recording,
It is irradiated on the lock-up pit of the optical information recording medium 1,
The return tracking laser beam reflected by the reflecting film 5 is collimated by the objective lens 12, passes through the two-divided optical rotation plate 14 again, and is incident on the prism block 15 again so that a part of the light amount thereof passes through the half mirror 15a. To Penetrate. The returned laser beam that has passed through the half mirror 15 a is reflected by the total reflection mirror 15 b, passes through the spatial light modulator 18, and enters the prism block 19.

A part of the tracking laser beam incident on the prism block 19 passes through the half mirror 19b. The return tracking laser beam transmitted through the half mirror 19b is
The light again enters the beam splitter 23, a part of the light amount is reflected by the half mirror 23a, passes through the convex lens 27 and the cylindrical lens 28 in order, and then the intensity thereof is individually detected by the four-division photodetector 29. After being calculated, the intended error signal is output from the detection circuit.

Each detection output of the four-division photo detector 29 is calculated by the detection circuit 85 shown in FIG. 7 to generate a focus error signal FE, a tracking error signal TE, a tracking error signal CE and a reproduction signal RF. Focus servo, based on the signal of
The tracking servo and the tracking servo control are performed, and the basic clock is reproduced and the address is determined.

Note that, in the setting during the above servo control in the address servo area, the configuration of the pickup 11 itself is a CD (compact disc), a DVD (digital video disc or a digital versatile disc), and an HS. The optical information recording / reproducing apparatus 10 embodying the present invention has the same address servo area as that of an ordinary optical disk apparatus because the recording / reproducing pickup has the same configuration as that of an ordinary optical disk such as a (hyper storage disk). With respect to the configuration of, it is possible to configure so as to have compatibility.

Therefore, even if the optical disk of the present invention is accidentally loaded into the normal optical disk device, after reading the information in the address servo area, a hologram is recorded in the information recording area in a format different from that of the normal optical disk. Because
The hologram is ejected from the normal optical disk device without being reproduced, and the normal optical disk device is not damaged.

Next, the outline of the operation for recording a hologram will be described with reference to FIGS. 3 and 6. In FIG.
During hologram recording, the spatial light modulator 18 selects a transmission state (hereinafter also referred to as “on”) or a blocking state (hereinafter also referred to as “off”) for each pixel according to the information to be recorded. , Spatially modulates a passing laser beam to generate information light. In the embodiment of the present invention, two pixels represent 1-bit information, and 2 pixels are always used to correspond to 1-bit information.
One of the pixels is turned on and the other is turned off.

Further, the phase spatial light modulator 17 follows the predetermined modulation pattern for the passing laser beam.
By selectively giving a phase difference of 0 (rad) or π (rad) with respect to a predetermined phase for each pixel, the phase of the laser beam is spatially modulated and the phase of the laser beam is spatially modulated. The reference light for recording modulated to is generated. The controller 90 (see FIG. 3) provides the phase spatial light modulator 17 with information of the modulation pattern selected by itself or the modulation pattern selected by the operation unit 91 (see FIG. 3) according to a predetermined condition, and the phase spatial light modulation is performed. The device 17 is the controller 9
The phase of the passing laser beam is spatially modulated according to the information of the modulation pattern given by 0 or selected by the operation unit 91.

The laser beam emitted from the laser light source 25 has a pulsed high output for recording. The controller 90 predicts the timing at which the laser beam emitted from the objective lens 12 passes through the information recording area 7 based on the basic clock reproduced from the reproduction signal RF, and the light emitted from the objective lens 12 is emitted from the information recording area 7. Keep the above settings while passing through. Further, while the laser beam from the objective lens 12 passes through the information recording area 7, focus servo control and tracking servo control are not performed and only tracking servo control is performed. Further, in the following description, it is assumed that the laser light source 25 emits P-polarized light.

As shown in FIG. 6, the P-polarized laser light emitted from the laser light source 25 is emitted from the collimator lens 24.
Is converted into a parallel-beam laser beam, passes through the beam splitter 30, enters the beam splitter 23, and part of the light amount passes through the half mirror 23 a and enters the prism block 19. A part of the light amount of the laser beam incident on the prism block 19 passes through the half mirror 19b and then passes through the spatial light modulator 18. At that time, the laser beam is spatially modulated according to the information to be recorded, and becomes the information light. Become.

This information light is reflected by the total reflection surface 15b of the prism block 15, and a part of the light amount is reflected by the half mirror 1.
After passing through 5a, it passes through the two-part optical rotation plate 14. Here, the laser beam that has passed through the optical rotation plate 14L of the two-part optical rotation plate 14 has its polarization direction rotated by + 45 ° to become an A-polarized laser beam, and the light that has passed through the optical rotation plate 14R has its polarization direction rotated by −45 °. It becomes a B-polarized laser beam. The information light of A-polarized light and B-polarized light that has passed through the two-division optical rotation plate 14 is
The optical information recording medium 1 is irradiated by the objective lens 12 so as to converge on the boundary surface between the hologram recording layer 3 of the optical information recording medium 1 and the substrate 4, that is, the reflection film 5.

On the other hand, the laser beam reflected by the half mirror 19b of the prism block 19 is reflected by the total reflection mirror 1.
The light is reflected by 9a and passes through the phase spatial light modulator 17, and at that time, the phase of the light is spatially modulated according to a predetermined modulation pattern to become a recording reference light. The recording reference light passes through the convex lens 16 and is converged. Part of the light amount of the recording reference light is reflected by the half mirror 15a of the prism block 15 and passes through the two-part optical rotatory plate 14.

Here, the optical rotation plate 14L of the two-part optical rotation plate 14
The polarization direction of the laser beam that has passed through is rotated by + 45 ° to become an A-polarized laser beam, and the polarization direction of the laser beam that has passed through the optical rotation plate 14R is rotated at -45 ° to become a B-polarized laser beam. A that passed through the two-part optical rotation plate 14
The polarized and B-polarized recording reference lights are applied to the optical information recording medium 1 and once converged by the objective lens 12 on the front side of the boundary surface between the hologram recording layer 3 and the substrate 4,
It passes through the hologram recording layer 3 while diverging.

For easy understanding, the polarization of light will be briefly described. A-polarized light is a straight line obtained by rotating S-polarized light by −45 ° or P-polarized light by + 45 °. The B polarized light is a linearly polarized light obtained by rotating S polarized light by + 45 ° or rotating P polarized light by −45 °. Therefore, the polarization directions of the A-polarized light and the B-polarized light are orthogonal to each other.

8 and 9 are explanatory views showing the state of the laser beam during recording. In the figure, the symbol 61 indicates P-polarized light, and the symbol 63 indicates A.
It represents polarized light, and the symbol indicated by reference numeral 64 represents B polarized light. In FIG. 8, the information light 51L that has passed through the optical rotation plate 14L of the two-division optical rotation plate 14 becomes A-polarized light, which is irradiated onto the optical information recording medium 1 by the objective lens 12 and passes through the hologram recording layer 3. The light converges on the reflection film 5 and is reflected by the reflection film 5 to go back inside the hologram recording layer 3 again.

The recording reference light 52L that has passed through the optical rotator 14L of the two-part optical rotator 14 becomes A-polarized light, which is irradiated onto the optical information recording medium 1 by the objective lens 12 and enters the hologram recording layer 3. After converging once on the surface, it passes through the hologram recording layer 3 while diverging. Then, in the hologram recording layer 3, A reflected by the reflection film 5
The polarized information light 51L and the A-polarized recording reference light 52L traveling toward the reflection film 5 interfere with each other to form an interference pattern three-dimensionally in the hologram recording layer. Therefore, when the output of the light emitted from the laser light source 25 becomes high, the interference pattern is stereoscopically recorded in the hologram recording layer 3.

Further, as shown in FIG. 9, the information light 51R that has passed through the optical rotation plate 14R of the two-division optical rotation plate 14 becomes B-polarized light, and the objective lens 12 causes the optical information recording medium 1
To the reflection film 5 after passing through the hologram recording layer 3.
It converges upward and is reflected by the reflection film 5, and again travels in the opposite direction in the hologram recording layer 3. Further, the recording reference light 52R that has passed through the optical rotation plate 14R of the two-divided optical rotation plate 14
Becomes B-polarized light, which is irradiated onto the optical information recording medium 1 by the objective lens 12, converges once on the incident surface of the hologram recording layer 3, and then passes through the hologram recording layer 3 while diverging. Then, in the hologram recording layer 3,
B-polarized information light 51R reflected by the reflection film 5 and the reflection film 5
When the B-polarized recording reference light 52R traveling toward the front side interferes with each other to form a three-dimensional interference pattern and the output of the emitted light of the laser light source 25 becomes a high output, the interference pattern is in the hologram recording layer 3. It is recorded three-dimensionally.

In the hologram recording mode of the present invention shown in FIGS. 8 and 9, the information light and the recording reference light are arranged so that the optical axis of the information light and the optical axis of the recording reference light are arranged on the same line. Are irradiated onto the hologram recording layer 3 from the same surface side. Further, by performing the recording operation a plurality of times on the hologram recording layer 3 at the same recording position in the information recording area by changing the modulation pattern of the recording reference light, it is possible to multiplex record the information by phase encoding multiplexing. Is.

In this way, in the recording apparatus for carrying out the present invention, the reflection type (Lippmann type) hologram is formed in the hologram recording layer 3. The A-polarized information light 51L and the B-polarized recording reference light 52R do not interfere with each other because their polarization directions are orthogonal to each other.
Since the polarization directions of the 1R and A-polarized recording reference light 52L are orthogonal to each other, they do not interfere with each other. That is, when recording a hologram, there is an advantage that extra interference fringes can be prevented from occurring and a reduction in the SN (signal to noise) ratio can be prevented.

Further, in the recording apparatus embodying the present invention, the information light is irradiated so as to converge at the boundary surface between the hologram recording layer 3 and the substrate 4 in the optical information recording medium 1 as described above, and the optical information is recorded. It is reflected by the reflective film 5 of the recording medium 1 and returns to the objective lens 12 side. This return light is incident on the four-division photodetector 29 in the same manner as during servo. Therefore, it is possible to perform focus servo in the address servo area even at the time of recording, by using the information light incident on the four-division photo detector 29.

The recording reference light is converged on the incident surface of the hologram recording layer 3 of the optical information recording medium 1 and the embossed pits in the address servo area are irradiated with divergent light, so that the optical information recording is performed. Even if the light is reflected by the reflection film 5 of the medium 1 and returns to the objective lens 12 side, it does not form an image on the four-division photodetector 29, and therefore cannot be used for focus servo.

In the above recording apparatus, by moving the convex lens 16 back and forth and changing its magnification,
It is also possible to arbitrarily select the size of the area (hologram formation area) in which one interference pattern of the information light and the reference light is stereoscopically recorded in the hologram recording layer 3.

Next, the operation when reproducing the recorded information will be described with reference to FIG. 6 again. During playback, spatial light modulator 1
All 8 pixels are turned on. Also, the controller 90
(See FIG. 3) gives the same information as the modulation pattern of the recording reference light at the time of recording the information to be reproduced to the phase spatial light modulator 17, and the phase spatial light modulator 17 is given from the controller 90. According to the same information as the modulation pattern at the time of recording information, the phase of the passing laser beam is spatially modulated, and the phase of the laser beam is spatially modulated,
Reference light for reproduction is generated.

The output of the laser light emitted from the laser light source 25 is switched to a low output for reproduction, and the controller 90 causes the laser beam which has passed through the objective lens 12 based on the basic clock reproduced from the reproduction signal RF. When the laser beam from the objective lens 12 passes through the information recording area 7, the reproduction time is set as described above. Therefore, the objective lens 1
While the laser beam from 2 passes through the information recording area 7, focus servo control and tracking servo control are not performed, and only tracking servo control is performed.

As shown in FIG. 5, the P-polarized laser beam emitted from the laser light source 25 is converted into a parallel laser beam by the collimator lens 24, passes through the beam splitter 30, and enters the beam 23. A part of the light amount is reflected by the half mirror 23a and enters the photodetector 26 for automatic light amount adjustment, and the laser beam transmitted through the half mirror 23a enters the prism block 19. Part of the light incident on the prism block 19 is reflected by the half mirror 19b, and the reflected light is reflected by the total reflection mirror 19a and passes through the phase spatial light modulator 17, at which time a predetermined modulation is performed. According to the pattern, the phase of the light is spatially modulated and becomes the reproduction reference light.

The reproduction reference light passes through the convex lens 16 and is converged. A part of the reproducing reference light is reflected by the half mirror 15a of the prism block 15,
It passes through the two-part optical rotation plate 14. Here, the two-part optical rotation plate 1
The light passing through the optical rotation plate 14L of No. 4 has its polarization direction rotated by + 45 ° to become A-polarized light, and the light passing through the optical rotation plate 14R has its polarization direction rotated by −45 °, and becomes B-polarized light. Become. The reproduction reference light that has passed through the two-part split optical rotation plate 14 is
The optical information recording medium 1 is irradiated through the objective lens 12, converges on the front side of the hologram recording layer 3, and then passes through the hologram recording layer 3 while diverging.

In FIGS. 10 and 11, the symbol indicated by reference numeral 61 represents P-polarized light, and the symbol indicated by reference numeral 62 is S.
The symbol 63 represents the polarized light, the symbol 63 represents the A polarized light, and the symbol 64 represents the polarized B light. In FIG. 10, the reproduction reference light 53L that has passed through the optical rotation plate 14L of the two-division optical rotation plate 14 becomes A-polarized light, which is irradiated onto the optical information recording medium 1 by the objective lens 12 and converges on the front side of the hologram recording layer 3. After that, it passes through the hologram recording layer 3 while diverging. As a result, from the hologram recording layer 3,
The reproduction light 54L corresponding to the information light 51L at the time of recording is generated. The reproduction light 54L travels toward the objective lens 12 side and is converted into a parallel light beam by the objective lens 12.
It again passes through the two-divided optical rotation plate 14 and becomes S-polarized light.

Further, as shown in FIG. 11, the reproduction reference light 53R that has passed through the optical rotation plate 14R of the two-division optical rotation plate 14 becomes B-polarized light, which is irradiated onto the optical information recording medium 1 by the objective lens 12. After converging on the front side of the hologram recording layer 3, it passes through the hologram recording layer 3 while diverging. As a result, the reproduction light 54R corresponding to the information light 51R at the time of recording is generated from the hologram recording layer 3. The reproduction light 54R travels toward the objective lens 12, is converted into a parallel light beam by the objective lens 12, and is again converted into a laser beam of 2
The light passes through the split optical rotation plate 14 and becomes S-polarized light.

The reproduction light which has passed through the two-divided optical rotation plate 14 is incident on the prism block 15 and a part of it is transmitted through the half mirror 15a. The reproduction light transmitted through the half mirror 15a is reflected by the total reflection mirror 15b, passes through the spatial light modulator 18 in which all pixels are turned on, and a part of the light amount is reflected by the half mirror 19b of the prism block 19. , C
It is incident on the CD array 20, and an on / off pattern by the spatial light modulator 18 at the time of recording is imaged on the CCD array 20. By detecting this pattern, the pattern is recorded on the optical information recording medium 1. Information is reproduced.

When a plurality of pieces of information are multiplexed and recorded on the hologram recording layer 3 by changing the modulation pattern of the recording reference light, the same modulation as the modulation pattern of the recording reference light is included in the plurality of pieces of information. Only the information read by the reference light for reproducing the pattern is reproduced. 10 and 11
In the example in which the optical axis of the reproduction reference light and the optical axis of the reproduction light are arranged on the same line, and the irradiation of the reproduction reference light and the collection of the reproduction light are performed from the same side of the hologram recording layer 3. is there.

Further, a part of the reproduction light is used for the four-division photodetector 2 like the return light at the time of servo during recording.
It is incident on 9. Therefore, this 4-division photo detector 2
It is possible to perform focus servo in the address servo area even at the time of reproduction by using the light incident on 9. It should be noted that the reference beam for reproduction is once converged on the front side of the hologram recording layer 3 in the optical information recording medium 1 and becomes divergent light in the hologram recording layer. Even if it is reflected and returns to the objective lens 12 side, no image is formed on the four-division photodetector 29.

The outline of the operation of the 4-division photo detector will be described with reference to FIG.
2 shows a specific example of the detection circuit 85 connected to the detector 29. The detection circuit 85 includes an adder 31 for adding the outputs of the light receiving portions 29a and 29d on the diagonal line of the four-division photo detector 29, and Split photo detector 2
Focusing error signal FE by the astigmatism method by obtaining the difference between the output of adder 31 and the output of adder 32 and adder 32 for adding the outputs of light receiving sections 29b and 29c on the other diagonal line of 9 And a light receiving section 29 adjacent to each other in the track direction of the four-division photodetector 29.
Similarly to the adder 34 that adds the outputs of a and 29b,
An adder 35 for adding the respective outputs of the light receiving portions 29c and 29d adjacent to each other in the track direction of the divided photo detector 29;
Obtaining the difference between the output of the adder 34 and the output of the adder 35,
The subtractor 36 for generating the tracking error signal TE by the push-pull method and the light receiving portions 29a, 29 that are adjacent to each other in the direction perpendicular to the track direction of the four-division photo detector 29.
An adder 38 for adding the respective outputs of c and an adder 39 for adding the respective outputs of the light receiving sections 29b and 29d adjacent to each other in the direction orthogonal to the track direction of the four-division photodetector 29 in the same manner.
And a subtractor 40 for generating a difference between the output of the adder 38 and the output of the adder 39 to generate the tracking error signal CE by the push-pull method, and the output of the adder 34 and the adder 35.
And an output of the adder 37 to generate a reproduction signal RF.
It has and.

In carrying out the present invention, the hologram forming wavelength λ emitted from the laser light source 25 is used as a laser beam for irradiating the optical information recording medium from the optical head.
₂ laser beam, the information recording position of the moving optical information recording medium, the irradiation position of the laser beam for hologram formation, the time required for exposure, so as to follow without displacement,
In order to perform tracking servo control for the optical head, a lockup pit provided in an information recording area is irradiated with a tracking laser beam, and an optical information recording medium at an information recording position and a laser beam irradiation position for hologram formation. The optical head 11 for the optical information recording medium according to the present invention requires a tracking laser beam having a wavelength λ ₁ emitted from the laser light source 33 for detecting the positional deviation in the moving direction of
For example, it is configured so that coherent laser beams having a plurality of wavelengths λ ₁ and λ ₂ can be emitted.

[0097] Wavelength .lambda.1, as a combination of a plurality of wavelengths of the wavelength λ _2, λ ₁ = 780nm, the combination of _{λ 2 = 532nm, λ 1 =} 780nm, λ 2 = 650nm combination of, lambda ₁
= 650 nm, λ ₂ = 525 nm combination, λ ₁ = 650
nm, λ ₂ = 405 nm combination, λ ₁ = 780 nm, λ ₂
= 390 nm combination and the like. The apparatus of FIG. 6 exemplifies an apparatus provided with two laser light sources 25 and 33 having different wavelengths. However, a single laser light source and a wavelength selection element such as a prism or a diffraction grating are used instead of the two kinds of laser light sources. Variable wavelength laser light source device capable of emitting laser beams of a plurality of wavelengths, or a variable wavelength laser light source device using a laser beam source and a nonlinear optical system for converting the wavelength of light emitted from the laser beam source. Etc. can also be used.

The recording of the hologram in the information recording area of the optical information recording medium (see FIG. 1 and a partially enlarged view thereof, FIG. 12) has a spiral shape which is spaced at a pitch of 0.8 μm in the radial direction of the optical information recording medium. Each recordable track has information recording areas aligned through a header in the circumferential direction, and when recording holograms sequentially at a plurality of information recording positions in each information recording area, optical information is recorded by a laser beam for hologram formation. While the recording medium moves at a distance of at least 200 μm, it is necessary to fix the hologram on the hologram recording layer by causing the information recording position to follow without causing a positional deviation and continuing irradiation.

When the optical information recording medium moves 200 μm and the recording of the hologram is completed, the optical head
200 μm-in the direction opposite to the moving direction of the optical information recording medium
α (where α is the distance between adjacent information recording positions) is rapidly returned, and a laser beam for hologram formation is used to record a new hologram at the next information recording position of the optical recording medium in the same recording mode. Then, irradiation to the next information recording position is started, and while the optical information recording medium moves by 200 μm, the information recording position is accurately tracked to the information recording position while being followed by the laser beam for hologram formation.

Such hologram recording operation is sequentially repeated until the next address / servo area is reached. While the optical head passes through the address servo area, focus servo control and tracking servo control are performed as described above, and when the information head moves to the information recording area of the next sector, the tracking servo control is performed and the same hologram recording The recording operation is repeated, and holograms are sequentially recorded at the information recording position of the information recording area of the next sector.

The physical structure of the optical information recording medium for recording a hologram according to the present invention is such that address information is provided as an emboss pit in each address / servo area, that is, a header portion for each land track and globe track. An information recording area consisting of a land track and a globe track is provided subsequent to. In one example of the optical information recording medium of the present invention, the optical information recording medium is irradiated with the laser light focused by the objective lens, and the laser light reflected and returned by the reflective film is collected by the same objective lens. Transfer function OTF (Optical Tra
nsfer Function) only needs to find the autocorrelation of two circular apertures. In the case of an optical system having a circular aperture without aberration, as shown in FIG. From the diagram showing the relationship between MTF (Modulation Transfer Function) and the wavelength of the spatial frequency, the limit of the pit length at which the degree of modulation disappears can be obtained. Calculating this for a tracking laser beam with a wavelength of 780 nm, λ
/2NA=780/2x0.5=780nm=0.78μ
m ≈ 0.8 μm, 0.4 μmφ at 0.8 μm intervals
When the lock-up pits are aligned, the degree of modulation due to the aligned lock-up pits disappears, so that it can be regarded as a line that is apparently connected.

Therefore, for example, when pre-formatting lock-up pits each having a diameter of about 0.4 μmφ on each land track and globe track line of the information recording area, 1.2 μm on each track on both sides of the lock-up pits. By providing the width of the mirror area, it is possible to avoid that the degree of modulation is lost due to the proximity of the lock-up pit and the adjacent groove and it becomes equivalent to being apparently connected, and the lock-up pit is isolated by the tracking laser beam. Can be detected.

On the other hand, since the distance between the center lines of the land track and the groove track adjacent to each other in the radial direction of the optical information recording medium is 0.8 μm, the diameter is about 0.4 μmφ.
When each of the lock-up pits is provided in each track, the interval between the peripheral edges of the lock-up pits adjacent in the radial direction of the optical information recording medium is 0.4 μm, and the lock-up pits in the radial direction of the optical information recording medium are The degree of modulation disappears, and the lock-up pits aligned in the radial direction can be regarded as a line that is apparently continuous. Therefore, tracking servo control of the optical head in the moving direction of the optical information recording medium can be performed extremely accurately. it can. Therefore, the information recording position of the moving optical information recording medium and the irradiation position of the laser beam for hologram formation from the optical head can be fixed for the time required for exposure without causing a positional deviation, and a low output laser light source. Even if is adopted, the hologram can be recorded with high accuracy.

Further, in the practice of the present invention, the lock-up pit is selected to have a depth of about ½ of the wavelength λ ₂ of the recording laser beam, so that the lock-up pit is protected from the recording laser beam. And the round-trip optical path difference with the reflected light from its periphery is made equal to λ ₂ so that they are in phase and the influence of the irradiation wave is eliminated, and the phase difference is eliminated for the tracking laser beam of wavelength λ _1. By making it possible to detect a tracking servo error by a push-pull method, for example, the misregistration detection necessary for tracking servo control can be satisfactorily performed. Therefore, for example, the wavelength of the tracking laser light emitted toward the lock-up pit is selected to be wavelength λ ₁ = 780 nm (red light), and the wavelength of the laser light used for hologram recording / reproduction is wavelength λ ₂ = 532 nm. Different from (green light), the depth of the lock-up pit is chosen to be 532 / 2nm = 266nm. Such selection of the wavelength is such that when the irradiated laser beam is diffracted by the lock-up pit, the tracking laser beam causes a phase difference between the incident tracking laser beam and the diffracted light, such as the push-pull method. The tracking servo error can be detected by
In the case of a hologram forming laser beam, the tracking servo control is affected by the information recording laser beam by making the phase relationship between the diffracted light from the lock-up pit and the incident hologram forming laser beam in-phase. I try not to be done.

FIG. 14 shows the relationship between the lock-up pit in the present invention and the mirror zones having a smooth width of 1.2 μm, which are provided on each track on both sides of the lock-up pit and are equal to the land surface of the land track. In the present invention, the wide mirror zones are provided on both sides of the lock-up pit in this manner, thereby eliminating the possibility of introducing an error component by the adjacent groove when detecting the positional deviation. Further, the lock-up pits provided in advance as a pre-format in the information recording area of the optical information recording medium do not necessarily have a one-to-one relationship with each information recording position in the information recording area, and one lock-up pit is formed in plural. Needless to say, it is possible to make a modification such that the tracking servo control can be performed corresponding to the information recording position.

In recording the hologram on the optical information recording medium according to the present invention, holograms are sequentially recorded on the land track and the globe track at intervals of d = 5 μsec × S (where S is the speed at which the optical information recording medium moves). Will be. In recording a hologram on such an optical information recording medium, each information recording position of the moving optical information recording medium is irradiated with a laser beam for hologram formation, that is, in one specific example, the diameter is converged to about 500 μmφ. 150x
It is performed by irradiating with a hologram forming laser beam irradiation spot by information light having pixel information of 150 = 2225 bits and recording reference light phase-modulated for each of the same number of pixels. In order to perform accurate recording at the information recording positions on the globe track sequentially, while the information recording positions move at least 200 μm along with the movement of the optical information recording medium, the information recording positions are laser beam spots for hologram formation. It is necessary to keep on irradiating the laser beam without misalignment.

Therefore, in the present invention, in the information recording area,
Pre-formed embossed pits with a diameter of approximately 0.4 μm
If the φ lock-up pit is irradiated with the tracking laser beam and a position shift occurs between the movement of the optical information recording medium and the irradiation spot of the tracking laser beam, the hologram recording position and the irradiation spot by the hologram forming laser beam Between the and, it is determined that the same amount of positional deviation has occurred, the positional deviation is detected from the relative positional relationship between the lockup pit and the irradiation spot of the tracking laser beam, and based on the detected positional deviation, The laser beam irradiation position of the optical recording medium and the hologram forming laser beam is aligned with the information recording position of the information recording area of the optical information recording medium, that is, the tracking servo control in the moving direction of the optical information recording medium is performed, and the low output laser It satisfies the above-mentioned conditions required for hologram recording using a light source.

FIG. 15 shows the relative positional relationship between the lock-up pit and the irradiation spot of the tracking laser beam by the push-pull method. The tracking error signal CE is detected by the error for servo control shown in FIG. It is performed by the detection circuit. In FIG. 15, when the tracking laser beam is projected onto the lock-up pit, the tracking laser beam is diffracted at the edge of the lock-up pit. When the tracking laser beam is correctly projected onto the lock-up pit, the return beams due to the diffraction generated at the edge of the lock-up pit are equal to each other (Fig. 1).
5 (b)), when the tracking laser beam is applied to the front part of the lock-up pit (when the movement of the optical information recording medium is delayed), as shown in FIG. The return beam diffracted and returned by the edge part of the beam is biased forward, and when the tracking laser beam is applied to the rear part of the lock-up pit (when the movement of the optical head is delayed), FIG. ), The return beam diffracted by the edge portion of the lock-up pit and returning returns is biased to the rear. Therefore, the deviation is detected by the four-division photodetector 29 in FIG. 6, and the detection shown in FIG. The tracking error signal CE is derived by calculation by the circuit 85.

[0109]

As described above, in the recording method and recording apparatus of the present invention, the information recording position in the information recording area of the moving optical information recording medium is irradiated with the predetermined section, the information beam and the recording reference beam. Since a servo control means for accurately following the position is provided and the information recording position can be accurately irradiated with the information light and the recording reference light in a predetermined section without causing a positional deviation, a low-output laser light source is used. Since it is possible to integrate the irradiation light amount of the laser light of the above in a predetermined section, it is possible to perform the same recording as the recording of the hologram by the laser light from the high-power laser light source, and a very practical hologram recording method and recording device. Can be provided.

Furthermore, the optical information recording medium is a conventional DVD.
Accurate hologram recording can be easily performed by only changing a part of the optical head and the servo control circuit of the recording device, and even if the optical information recording medium of the present invention is accidentally loaded into an ordinary optical disc device. After reading the information in the address / servo area, since the hologram is recorded in the information recording area, the optical information recording medium of the present invention is ejected from the normal optical disk device and damages the normal optical disk device. Since it is not given, there is no problem in practical use.

[Brief description of drawings]

FIG. 1 is an optical information recording medium showing a part of a track embodying the present invention.

FIG. 2 is an optical information recording medium showing an enlarged track portion according to the present invention.

FIG. 3 is a block diagram showing the configuration of an optical information recording / reproducing apparatus for carrying out the present invention.

FIG. 4 is a plan view showing an example of an optical head of an optical information recording / reproducing apparatus for carrying out the present invention.

FIG. 5 is a plan view showing another example of the optical head of the optical information recording / reproducing apparatus for carrying out the present invention.

FIG. 6 is an explanatory diagram of an optical system of an optical head of an optical information recording / reproducing apparatus for carrying out the present invention.

FIG. 7 is a schematic diagram of a detection circuit of an optical information recording / reproducing apparatus that implements the present invention.

8 is an explanatory diagram showing a state of light during hologram recording by the optical head shown in FIG.

9 is an explanatory diagram showing a state of light during hologram recording by the optical head shown in FIG.

10 is an explanatory diagram showing a state of light when a hologram is reproduced by the optical head shown in FIG.

11 is an explanatory diagram showing a state of light when a hologram is reproduced by the optical head shown in FIG.

FIG. 12 is an explanatory view showing an enlarged track portion of an optical information recording medium embodying the present invention.

FIG. 13 is a diagram schematically showing the transfer function (MTF) of amplitude and the limit of resolution when a pit is irradiated with a laser beam.

FIG. 14 is an explanatory diagram showing an enlarged view of a lock-up pit portion of a track of an optical information recording medium embodying the present invention.

FIG. 15 is an explanatory view showing an enlarged relationship between a lockup pit portion of a track and a tracking laser beam spot of the optical information recording medium embodying the present invention.

FIG. 16 is an optical information recording medium showing a part of a track on which a conventional hologram is recorded.

FIG. 17 is an explanatory diagram of an optical system of an optical head of a conventional optical information recording / reproducing device.

[Explanation of symbols]

1 recording medium 2 transparent substrate 3 Information recording layer 4 substrates 5 Reflective film 6 address servo area 7 Information recording area 7'information recording position 8 lock-up pits 10 Optical information recording / reproducing apparatus 11 Optical head 12 Objective lens 13 Servo mechanism 14 Polarizing plate 15 prism block 16 convex lens 17 Phase spatial light modulator 18 Spatial light modulator 19 prism block 20 CCD array 23 Beam splitter 24 Collimator lens 25 laser light source 26 Photo Detector 27 Convex lens 28 Cylindrical lens 29 Light receiving part 30 beam splitter 31 Photo Detector 32 convex lens 33 Laser light source

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) G11B 7/24 571 G11B 7/24 571B F term (reference) 2K008 AA04 AA17 BB05 BB06 DD13 EE01 EE04 FF07 FF17 FF27 HH01 HH11 HH18 HH20 HH26 HH28 5D029 PA03 5D090 AA01 BB20 CC01 DD03 EE01 FF50 JJ03 KK12 KK14 5D118 AA13 BA01 BB02 BC12 BC13 BF03 CA13

Claims (14)

[Claims] 1. An optical information recording apparatus for recording information as a hologram at an information recording position in each information recording area of an optical information recording medium having a plurality of address / servo areas and information recording areas, wherein: Irradiating means for irradiating the optical information recording medium with the information light and the reference light so that a hologram is formed by an interference fringe pattern of the information light and the reference light at the information recording position of the optical information recording medium, An optical information recording medium moving means for moving the optical information recording medium, and a positional deviation detecting means for detecting a relative positional deviation between the moving information recording position and the irradiation position of the information light and the reference light based on the positioning information. In order to move the irradiation position to the information recording position while locking the irradiation position for a predetermined section, the irradiation unit is moved along the moving direction of the optical information recording medium based on the output of the position deviation detecting unit. The optical information recording apparatus characterized by comprising a an irradiation position moving means for moving Te. 2. The optical information according to claim 1, wherein the positional deviation detecting means detects the positional deviation based on at least one positioning information provided at a predetermined position in the information recording area. Recording device. 3. The irradiation position moving means is adapted to move the irradiation means back and forth along the moving direction of the optical information recording medium in accordance with the output of the position shift detecting means. The optical information recording device as described in 1 or 2. 4. Identification information for identifying each information recording area is recorded in each address / servo area of the optical information recording medium, and the positioning information in the position deviation detecting means is recorded in each track. 4. The optical information recording device according to claim 1, wherein at least one lock-up pit is provided for each information recording area. 5. The optical information recording according to claim 1, wherein the positional deviation is detected by the positional deviation detecting means in parallel with the recording of the hologram at the information recording position. apparatus. 6. The positional deviation detecting means detects the positional deviation by irradiating the positioning information with a light beam having a wavelength different from that of the information light and the reference light for recording information. Item 6. The optical information recording device according to any one of items 1 to 5. 7. The optical information recording apparatus according to claim 6, wherein the positional deviation detecting means irradiates the positioning information with a light beam having a wavelength longer than that of the information light and the reference light. 8. The wavelength of the information light and the reference light for recording the hologram is about ½ of the wavelength of the position deviation detecting light beam for irradiating the lock-up pit. 7. The optical information recording device described in 7. 9. An optical information recording method for recording information by a hologram in each information recording area in an optical information recording medium having a plurality of information recording areas, the method comprising: moving the optical information recording medium; The step of irradiating the optical information recording medium with the information light and the reference light so that an interference fringe pattern of the information light and the reference light is formed at the information recording position of the information recording area, and the moving information recording area. A step of causing the irradiation means to follow the movement of the optical information recording medium so that the relative position between the information recording position and the irradiation position of the information light and the reference light does not shift in a predetermined section, Optical information recording method. 10. The step of causing the irradiation means to follow the movement of the optical information recording medium includes a position of a lock-up pit provided in an information recording area of the optical information recording medium and a position of a wavelength different from that of the information light and the reference light. 10. The optical information recording method according to claim 9, wherein the optical information recording method is performed by detecting a positional deviation in the moving direction of the optical information recording medium with respect to the deviation detecting light beam. 11. The step of causing the irradiation means to follow the movement of the optical information recording medium includes a position of a lock-up pit provided in an information recording area of the optical information recording medium and a position of a wavelength different from that of the information light and the reference light. 11. The method according to claim 9, further comprising the step of detecting a positional shift in the moving direction of the optical information recording medium with respect to the shift detecting light beam, and moving the irradiation position of the information light and the reference light by servo control. Optical information recording method. 12. The irradiation of the light beam for detecting the positional deviation to the lock-up pit is performed in parallel with the irradiation of the information light and the reference light to the information recording position. The optical information recording method according to claim 11. 13. The magnetic controller provided in the optical head moves the irradiation positions of the information light and the reference light by servo control in the moving direction of the optical information recording medium. The optical information recording method according to claim 12. 14. The piezoelectric element control device provided in the optical head moves the irradiation position of the information light and the reference light by servo control in the moving direction of the optical information recording medium. 13. The optical information recording method according to claim 12.