WO2020012551A1 - Optical recording device, lightguide plate, and optical recording method - Google Patents

Optical recording device, lightguide plate, and optical recording method Download PDF

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Publication number
WO2020012551A1
WO2020012551A1 PCT/JP2018/025992 JP2018025992W WO2020012551A1 WO 2020012551 A1 WO2020012551 A1 WO 2020012551A1 JP 2018025992 W JP2018025992 W JP 2018025992W WO 2020012551 A1 WO2020012551 A1 WO 2020012551A1
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WIPO (PCT)
Prior art keywords
optical recording
recording medium
light
recording device
phase difference
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PCT/JP2018/025992
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French (fr)
Japanese (ja)
Inventor
敦 根尾
健 宇津木
利樹 石井
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株式会社日立製作所
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Priority to PCT/JP2018/025992 priority Critical patent/WO2020012551A1/en
Publication of WO2020012551A1 publication Critical patent/WO2020012551A1/en

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/0045—Recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/0065—Recording, reproducing or erasing by using optical interference patterns, e.g. holograms
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector

Definitions

  • the present invention relates to an optical recording device, a light guide plate, and an optical recording method.
  • Patent Document 1 JP-A-2017-126390.
  • the publication discloses a light source that emits laser light, a laser light source, and a reference light source.
  • the optical information recording device multiplexes and records, as a hologram, an interference pattern between signal light and reference light on an optical information recording medium using holography.
  • An optical element that separates the signal light into signal light, an angle control unit that controls the incident angle of the reference light to the optical information recording medium, and a phase control unit that controls at least one phase of the signal light and the reference light during recording.
  • the angle control unit controls the angle interval so that the position of 1st @ null of the adjacent page of the signal light is fixed, and the phase control unit controls the signal light or the reference light so that the phase difference between the adjacent pages becomes a predetermined value. To control the phase ”.
  • Patent Document 1 includes a phase control unit for reducing crosstalk between adjacent pages, and needs to control the phase control unit in synchronization with each recording. That is, a time (300 microseconds or the like) for changing the angle of the reference light is provided as an interval between pages of writing, but if the phase control is not completed during that time, writing will be delayed. This is because not only does the apparatus cost increase due to the provision of the phase control unit, but if the time required for the phase control is longer than the interval between the writing pages, there is a possibility that the recording speed may decrease.
  • An object of the present invention is to realize high-speed recording while reducing the cost of an apparatus for optical recording and reading.
  • an optical recording device is an optical recording device that records an interference pattern between signal light and reference light as a hologram on an optical recording medium using holography by an angle multiplexing method.
  • high-speed recording can be realized while reducing the cost of an apparatus for optical recording and reading.
  • an optical recording device capable of recording with high speed and good quality without significantly increasing the device cost.
  • the method and an optical recording medium recorded with good quality can be provided.
  • FIG. 1 is a schematic diagram illustrating a configuration example of an optical recording / reproducing apparatus according to the present invention.
  • Schematic diagram showing a configuration example of a pickup (at the time of recording) Schematic diagram showing a configuration example of a pickup (during playback) Diagram showing an operation flow example of the preparation process Diagram showing an example of an operation flow of a recording process Diagram showing an example of the operation flow of the reproduction process Diagram showing the definition of the angle between the signal light and the reference light in the medium
  • Schematic diagram showing an example of inter-page crosstalk A diagram showing an example of a change in the amount of reproduced light due to a change in a phase difference between pages.
  • Conceptual diagram showing an example of phase control by movement control of an optical recording medium FIG.
  • FIG. 4 is a diagram showing a relationship between an amount of movement of an optical recording medium in an optical axis direction and a cosine value of a phase difference between pages
  • FIG. 9 is a diagram illustrating an example of an operation flow of data recording according to the second embodiment. The figure which shows the example of a structure of the light-guide plate which concerns on 3rd Embodiment.
  • holographic recording technology which uses holography to record digital information
  • an optical recording / reproducing apparatus using holography when recording is performed by narrowing an angle or a spatial distance, which is a parameter controlled at the time of multiplexing, to increase a recording density, a cross with an angularly or spatially reproduced signal is used. Since the talk component is increased and the quality of the reproduced signal is significantly deteriorated, there is a problem that the crosstalk must be reduced.
  • This is not limited to the storage, but is a problem that occurs similarly in the case of multiplex recording using holography. For example, it can be said that a problem also occurs in a light guide plate using holography.
  • the present invention can be embodied as an optical recording apparatus, but will be described as an optical recording / reproducing apparatus for the sake of description including effects at the time of reproduction.
  • FIG. 1 is a schematic diagram illustrating a configuration example of an optical recording / reproducing apparatus according to the present invention.
  • the optical recording / reproducing apparatus 10 is an optical recording medium recording / reproducing apparatus for recording and reproducing digital information using holography. As described above, the optical recording / reproducing apparatus 10 can perform both of recording information on an optical recording medium and reproducing information from the optical recording medium on which information is recorded. It may be a device that performs only the above.
  • the optical recording / reproducing device 10 is connected to an external control device 91 via an input / output control circuit 90.
  • the optical recording / reproducing device 10 receives an information signal to be recorded from the external control device 91 by the input / output control circuit 90.
  • the optical recording / reproducing device 10 transmits the reproduced information signal to the external control device 91 by the input / output control circuit 90.
  • the optical recording / reproducing apparatus 10 includes a pickup 11, a reproduction reference light optical system 12, a cure optical system 13, an optical recording medium rotation angle detecting optical system 14, and a rotation motor 50.
  • the structure is such that it can be rotated by 50.
  • the pickup 11 emits reference light and signal light to the optical recording medium 1 and records digital information on the optical recording medium 1 using holography.
  • a signal to be recorded is sent to a spatial light modulator in the pickup 11 by a controller 89 via a signal generating circuit 86 for modulating an information signal into page data, and the signal light is modulated by the spatial light modulator.
  • the reproduction reference light optical system 12 When information recorded on the optical recording medium 1 is reproduced, the reproduction reference light optical system 12 generates a light wave that causes the reference light emitted from the pickup 11 to be incident on the optical recording medium in a direction opposite to that at the time of recording. .
  • the reproduction light reproduced by the reproduction reference light is detected by the photodetector in the pickup 11, and the signal is reproduced by the signal processing circuit 85.
  • the irradiation time of the reference light and the signal light applied to the optical recording medium 1 can be adjusted by controlling the opening and closing time of the shutter in the pickup 11 by the controller 89 via the shutter control circuit 87.
  • the ⁇ cure optical system 13 has a role of generating a light beam used for pre-cure and post-cure of the optical recording medium 1.
  • Precuring is a pre-process of irradiating a predetermined light beam before irradiating a reference light and a signal light to a desired position when recording information at a desired position in the optical recording medium 1.
  • Post cure is a post-process in which information is recorded at a desired position in the optical recording medium 1 and then a predetermined light beam is irradiated to make it impossible to additionally record at the desired position.
  • the optical recording medium rotation angle detecting optical system 14 is used for detecting the rotation angle of the optical recording medium 1.
  • a signal corresponding to the rotation angle is detected by the optical recording medium rotation angle detecting optical system 14, and the controller 89 uses the detected signal to rotate the optical recording medium.
  • the rotation angle of the optical recording medium 1 can be controlled via the motor control circuit 88.
  • a predetermined light source driving current is supplied from the light source driving circuit 82 to the light sources in the pickup 11, the cure optical system 13, and the optical recording medium rotation angle detecting optical system 14, and each light source emits a light beam with a predetermined light amount. can do.
  • the pickup 11 and the cure optical system 13 are provided with a mechanism capable of sliding the position of the optical recording medium 1 in the radial direction, and the position is controlled via the access control circuit 81.
  • the recording technique using the principle of angle multiplexing of holography tends to have an extremely small allowable error with respect to the deviation of the reference beam angle. Therefore, a mechanism for detecting the shift amount of the reference light angle is provided in the pickup 11, a servo control signal is generated by the servo signal generation circuit 83, and the shift amount is corrected via the servo control circuit 84. Servo mechanism is provided in the optical recording / reproducing apparatus 10. Further, the servo signal generation circuit 83 can also generate a total value of light amounts detected by a photodetector in the pickup 11.
  • the pickup 11, the cure optical system 13, and the optical recording medium rotation angle detecting optical system 14 may be simplified by integrating some optical system configurations or all optical system configurations into one.
  • the optical recording medium position control circuit 100 can control the relative position between the optical recording medium 1 and the pickup 11 by moving the rotary motor 50 so as to change the distance between the optical recording medium 1 and the pickup 11.
  • a stepping motor for moving the position of the rotation motor 50 in the direction of the rotation axis of the rotation motor 50 is attached, and the optical recording medium position control circuit 100 controls the operation of the stepping motor. That is, the optical recording medium position control circuit 100 can change the positional relationship between the optical pickup device 11 and the optical recording medium 1 when recording.
  • the optical recording medium position control circuit 100 can change the positional relationship when the optical recording medium 1 is mounted, or can change the positional relationship more finely, for example, every page writing as shown in the second embodiment. You can also.
  • FIG. 2 is a schematic diagram illustrating a configuration example (at the time of recording) of the pickup.
  • the configuration example of the pickup 11 the recording principle of the basic optical system configuration of the pickup 11 in the optical recording / reproducing apparatus 10 is shown.
  • the light beam emitted from the light source 301 passes through the collimator lens 302 and enters the shutter 303.
  • the optical element 304 including, for example, a half-wave plate or the like causes the light amount ratio between the p-polarized light and the s-polarized light to be a desired ratio.
  • the polarization direction is controlled.
  • the light beam is incident on a PBS (Polarization Beam Splitter) prism 305.
  • PBS Polarization Beam Splitter
  • the light beam transmitted through the PBS prism 305 functions as a signal light 306, and after the light beam diameter is expanded by a beam expander 308, the light beam passes through a phase mask 309, a relay lens 310, and a PBS prism 311, and passes through a spatial light modulator 312.
  • the phase mask 309 is an element that intentionally disturbs the wavefront of the signal light so as to reduce the concentration of the light amount when the signal light is collected by the objective lens. This can reduce local consumption of the recording material in the optical recording medium.
  • the signal light 306 to which the page data is added by the spatial light modulator 312 is reflected by the PBS prism 311 and propagates through the relay lens 313 and the spatial filter 314. After that, the signal light 306 is focused on the optical recording medium 1 by the objective lens 315.
  • the light beam reflected by the PBS prism 305 functions as the reference light 307, and is set to a predetermined polarization direction by the polarization direction conversion element 316 according to recording or reproduction, and then passes through the mirror 317 and the mirror 318.
  • the light enters the mirror 319. Since the angle of the galvanomirror 319 can be adjusted by the actuator 320, the incident angle of the reference light 307 incident on the optical recording medium 1 after passing through the lenses 321 and 322 can be set to a desired angle. Note that an element that converts the wavefront of the reference light 307 may be used in place of the galvanomirror to set the incident angle of the reference light 307.
  • the angle of the reference beam 307 is defined as 0 degree in a direction perpendicular to the optical recording medium 1 as shown in the figure, a counterclockwise direction in the figure is defined as a positive direction, and a clockwise direction is defined as a negative direction.
  • the signal light 306 and the reference light 307 By causing the signal light 306 and the reference light 307 to be incident on the optical recording medium 1 so as to overlap each other at a predetermined angle in this manner, an interference fringe pattern is formed in the optical recording medium 1, and this pattern is Information is recorded by writing to the recording medium 1. Further, since the incident angle of the reference light incident on the optical recording medium 1 can be changed by the galvanomirror 319, the reference light and the signal light are caused to interfere with each other at least at two different angles, so that angle multiplexing is performed in the same area. Recording is possible.
  • a hologram corresponding to each reference light angle is referred to as a page
  • a set of pages angularly multiplexed in the same area is referred to as a book.
  • FIG. 3 is a schematic diagram illustrating a configuration example (during reproduction) of the pickup.
  • the reproduction principle of the basic optical system configuration of the pickup 11 in the optical recording / reproduction device 10 is shown.
  • the reference beam 307 is incident on the optical recording medium 1 as described above, and the light beam transmitted through the optical recording medium 1 is subjected to the angle adjustment by the actuator 323. By being reflected by the mirror 324, the reference light for reproduction is generated.
  • the reproduction light reproduced by the reproduction reference light propagates through the objective lens 315, the relay lens 313, and the spatial filter 314. After that, the reproduction light passes through the PBS prism 311 and enters the photodetector 325, so that the recorded page data can be reproduced.
  • the photodetector 325 for example, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor can be used. Any element can be used as long as it can be reproduced.
  • CMOS Complementary Metal Oxide Semiconductor
  • CCD Charge Coupled Device
  • FIG. 4 is a diagram showing an example of an operation flow of the preparation process. Here, a flow relating to recording / reproduction using holography will be particularly described.
  • FIG. 4 shows the operation flow from the insertion of the optical recording medium 1 into the optical recording / reproducing apparatus 10 to the completion of the preparation for recording or reproduction.
  • the optical recording / reproducing device 10 includes, for example, an input unit that receives light from the inserted medium, an output unit that outputs light, and a total reflection unit that totally reflects light. It is determined whether or not the optical recording medium 1 is used to record or reproduce information by using provided holography (step S601).
  • the inserted medium has an input unit for receiving light, an output unit for outputting light, and a total reflection unit for totally reflecting light, and a light for recording or reproducing information using holography. If it is determined that the medium is the recording medium 1, the optical recording / reproducing apparatus 10 reads the control data provided on the optical recording medium 1 (Step S602). For example, the optical recording / reproducing device 10 acquires information on the optical recording medium 1 and information on various setting conditions at the time of recording and reproduction.
  • the optical recording / reproducing apparatus 10 After reading out the control data, the optical recording / reproducing apparatus 10 performs various adjustments according to the control data and learning processing relating to the pickup 11 (step S603). Further, the optical recording / reproducing device 10 performs phase control learning for reducing inter-page crosstalk (step S604). Then, the optical recording / reproducing device 10 completes the preparation for recording or reproduction (step S605). The detailed operation of the phase control learning (step S604) for reducing inter-page crosstalk will be described later.
  • FIG. 5 is a diagram showing an example of an operation flow of a recording process. Here, a flow related to recording using holography will be particularly described.
  • the recording process of FIG. 5 shows an operation flow from the ready state to recording information on the optical recording medium 1.
  • the input / output control circuit 90 receives the information to be recorded (step S611) and sends it to the signal generation circuit 86. Then, the controller 89 performs various recording learning processes in advance as needed so that pages can be recorded on the optical recording medium 1 with high quality (step S612). For example, the controller 89 performs various recording learning processes such as power optimization of the light source 301 and optimization of the exposure time by the shutter 303, which are existing technologies, in advance.
  • the controller 89 performs a seek operation (step S613). Specifically, the controller 89 controls the access control circuit 81 to position the pickup 11 and the cure optical system 13 at predetermined positions on the optical recording medium 1. If the optical recording medium 1 has address information, the controller 89 reproduces the address information and checks whether the address information is positioned at the target position. If not, the controller 89 shifts from the predetermined position. The operation of calculating the amount and repositioning is repeated.
  • the access control circuit 81 precures a predetermined area using the light beam emitted from the cure optical system 13 (step S614).
  • the signal generation circuit 86 performs a two-dimensional data generation process of converting the information to be recorded into two-dimensional data (step S615).
  • the signal generation circuit 86 transmits the generated two-dimensional data to the spatial light modulator 312 in the pickup 11 and uses the reference light and the signal light emitted from the pickup 11 as two-dimensional data on the optical recording medium 1.
  • Information is recorded (step S616).
  • the access control circuit 81 performs post cure using the light beam emitted from the cure optical system 13 (step S617). The access control circuit 81 may verify the recorded two-dimensional data for errors as necessary.
  • FIG. 6 is a diagram showing an example of an operation flow of the reproduction process. Here, a flow relating to reproduction using holography will be particularly described.
  • the reproduction process in FIG. 6 shows an operation flow from the preparation completion state to the reproduction of information recorded on the optical recording medium 1.
  • the controller 89 performs a seek operation (step S621). Specifically, the controller 89 controls the access control circuit 81 to position the pickup 11 and the reproduction reference light optical system 12 at predetermined positions on the optical recording medium 1.
  • the controller 89 reproduces the physical address information and checks whether the physical address information is positioned at a target position. The amount of deviation from the position is calculated, and the operation of repositioning is repeated.
  • the controller 89 determines the rotation angle of the optical recording medium 1 and the radial position of the pickup 11 by accessing the optical recording medium rotation angle detecting optical system 14. The detection is performed using the control circuit 81, the amount of deviation from the target position is calculated, and the pickup 11 is operated in a direction in which the amount of deviation is reduced to perform predetermined positioning.
  • the pickup 11 emits the reference light
  • the reproduced image data which is the information recorded on the optical recording medium 1
  • the signal processing circuit 85 After the reproduction of the two-dimensional data header portion in the reproduced image data, The data is reproduced (step S622).
  • the input / output control circuit 90 transmits the data reproduced by the signal processing circuit 85 to the external control device 91 (step S623). If the target reproduced image data is not identified as a result of the data reproduction of the two-dimensional data header portion, the reproduced image data different from the target may be detected. The processing is stopped or the processing is executed again from the processing in step S621.
  • the above is the flow of performing the preparatory process and performing the recording or reproducing process after the optical recording medium is inserted into the optical recording and reproducing device 10.
  • the intensity and phase of the reproduction light will be described.
  • the intensity of the reproduction light that is, the amount of diffracted light can be expressed by Equation 1.
  • n is the refractive index of the optical recording medium 1
  • L is the thickness of the recording layer of the optical recording medium 1
  • ⁇ is the wavelength of the signal light 306 and the reference light 307
  • ⁇ MRS is the angle formed by the signal light 306 and the reference light 307.
  • ⁇ MS is the angle of the signal light 306 with respect to the normal to the optical recording medium 1
  • ⁇ MR is the angle shift during reproduction with respect to recording.
  • the angle in Expression 1 is an angle in the optical recording medium 1 and is affected by the refractive index of the optical recording medium 1.
  • FIG. 7 is a diagram illustrating the definition of the angle between the signal light and the reference light in the medium. Each angle is as described above. Also, angles in the air corresponding to ⁇ MRS , ⁇ MS , ⁇ MR , and ⁇ MR are set to ⁇ ARS , ⁇ AS , ⁇ AR , and ⁇ AR , respectively. Next, the influence of crosstalk from an adjacent page will be described with reference to FIG.
  • FIG. 8 is a schematic diagram showing an example of inter-page crosstalk. Specifically, it is a schematic diagram illustrating an example of crosstalk from an adjacent page.
  • Crosstalk from an adjacent page means an unnecessary signal component that leaks from a different page with respect to page data to be reproduced.
  • the horizontal axis shows a reference light angle
  • the vertical axis shows a reproduction light intensity.
  • the (n + 1) -th page which is an adjacent page is also reproduced.
  • the entire reproduced light intensity is represented by Expression 2.
  • I is the reference beam angle ⁇ n in the reproducing light amount
  • E n is the amplitude of the reproduction light of the n pages
  • phi is a first n pages (n + 1) th page Is the phase difference at the time of recording.
  • 2 of the first term is a desired reproduction signal
  • 2 of the second term is an unnecessary crosstalk component. (Noise component).
  • FIG. 9 is a diagram illustrating an example of a change in the reproduction light amount due to a change in the inter-page phase difference.
  • the reproduction light amount 901 is the reproduction light amount
  • the reproduction light amount 902 is the reproduction light amount
  • the reproduction light amount 900 is the entirety obtained from the nth and (n + 1) th pages. Is shown.
  • FIG. 9A shows the reproduction light amount when the phase difference ⁇ is 0
  • FIG. 9B shows the reproduction light amount when the phase difference ⁇ is 1/2 ⁇ ⁇
  • FIG. ) Shows the reproduction light amount when the phase difference ⁇ is ⁇ .
  • the reproduction light amount I (900) is greatly amplified.
  • the reproduction light amount I900 is the sum of the desired reproduction signal
  • >> since the second term there is a relationship is very small compared to the first term, approximate reproducing light quantity I is desired reproduction signal
  • the third term of Expression 2 has a negative value, and therefore the reproduction light amount I900 is attenuated.
  • the reproduction light amount I900 greatly changes depending on the phase difference ⁇ .
  • the waveform of the reproduction light amount I900 is characterized by the maximum value 903 and the maximum value 904 of the reproduction light amount I900 and the half width 905 and the half width 906.
  • the method of characterizing the phase difference between the reproduction light amount I900 and the adjacent page is not limited to these.
  • the phase difference with the adjacent page may be associated with not only the maximum light amount but also the number of the maximum value (the number of transition points from rising to falling on the graph of the reproduction light amount I900). .
  • FIG. 10 is a conceptual diagram showing an example of phase control by movement control of an optical recording medium. That is, the conceptual diagram shown in FIG. 10 is an example in which different inter-page phase differences are given by controlling the position of the optical recording medium. This mechanism will be described below.
  • the position of the pivot 103 which is the center of rotation of the reference light 102, is relatively shifted on the optical recording medium 1 by moving the optical recording medium 1 closer to or away from the pickup 11. That is, each optical path from the arbitrary phase 104 of the reference light at the reference light angle set at the time of recording the n-th page and the arbitrary phase 105 of the reference light at the reference light angle at the time of recording the (n + 1) page to the pivot 103 It can be said that the length changes by moving the optical recording medium 1 or the pickup 11.
  • the phase 104 before and after the movement of the optical recording medium 1 is the same before and after the movement, and similarly, the phase 105 before and after the movement of the optical recording medium 1 is the same before and after the movement.
  • an arbitrary phase 104 of the reference light at the reference light angle set at the time of recording the nth page and an arbitrary phase of the reference light at the reference light angle at the time of recording the (n + 1) th page Since each optical path length from 105 to the pivot 103 changes, the difference (Equation 3) between the optical path length from the phase 104 to the pivot 103 and the optical path length from the phase 105 to the pivot 103 before moving the optical recording medium 1 is The difference (Equation 4) between the optical path length from the phase 104 to the pivot 103 after moving the optical recording medium 1 and the optical path length from the phase 105 to the pivot 103 is different.
  • FIG. 11 is a diagram showing the relationship between the amount of movement of the optical recording medium in the optical axis direction and the cosine value of the inter-page phase difference. That is, FIG. 11 is an example of the relationship between the amount of movement of the optical recording medium 1 in the focus direction and the cosine value of the inter-page phase difference based on the focus position 801 of the optical recording medium 1.
  • the direction in which the distance between the optical recording medium 1 and the pickup 11 decreases becomes the positive movement amount of the optical recording medium 1, and the direction in which the distance between the optical recording medium 1 and the pickup 11 increases becomes the negative movement amount of the optical recording medium 1.
  • FIG. 12 shows an example of an operation flow of the phase control learning (step S604) for reducing inter-page crosstalk.
  • FIG. 12 is a diagram illustrating an example of an operation flow of the phase control learning process.
  • the servo signal generation circuit 83 generates a signal for servo control, and sets the angle of the reference beam on the recording page to a predetermined angle via the servo control circuit 84 in accordance with the progress of the recording page (step S60401).
  • the optical recording medium position control circuit 100 sets the position of the optical recording medium 1 in the optical axis direction at the time of recording, that is, the distance from the pickup 11 (step S60402). At this time, the optical recording medium 1 is set at a position different from the position of the optical recording medium 1 already recorded in the phase control learning before recording. Specifically, the optical recording medium position control circuit 100 moves the rotary motor 50 so as to change the distance between the optical recording medium 1 and the pickup 11 and determines the relative position between the optical recording medium 1 and the pickup 11 during recording. Is controlled to be a relative position different from the position of the optical recording medium 1.
  • the pickup 11 performs page recording (step S60403).
  • the servo signal generation circuit 83 calculates the total value of the light amounts detected by the photodetectors in the pickup 11, and calculates the three values as shown in FIGS. 9 (a), 9 (b), and 9 (c). It is determined whether to end the adjustment recording based on whether or not the adjustment recording of the pattern of the diffracted light amount (production of the hologram for learning) has been performed (step S60404). That is, it can be said that the servo signal generation circuit 83 determines whether or not the adjustment recording has been performed within a range in which the inter-page phase difference can be determined.
  • the present invention is not limited to this.
  • the determination of the end of the adjustment recording may be terminated when the optical recording medium 1 reaches a predetermined position, or when the page recording reaches a predetermined recording area.
  • the determination may be terminated, and the criterion is not limited to the above-described determination method.
  • step S60404 If it is determined that the adjustment recording has not been completed (“No” in step S60404), the controller 89 returns the control to the processing in step S60401. If it is determined that the adjustment recording has been completed (“Yes” in step S60404), the controller 89 acquires the amount of diffraction light of the learning hologram (step S60405). Specifically, the controller 89 acquires the amount of diffracted light while changing the reference light angles near all the pages recorded in step S60403.
  • the above is the phase control learning process (the process of step S604). This makes it possible to shift the pivot position formed by the reference light and the signal light in the defocus direction (to generate a difference in the optical path length), and to suppress crosstalk components from adjacent pages during reading even when multiplexing pages. Becomes possible.
  • high-speed recording can be realized while reducing the cost of an apparatus relating to optical recording and reading.
  • recording method of the angle multiplexing method using holography when performing recording with increased recording density, recording can be performed at high speed and with good quality without significantly increasing the apparatus cost.
  • the page interval is reduced, by controlling the phase difference between pages by controlling the position of the optical recording medium 1, it is possible to effectively reduce the crosstalk while maintaining the apparatus cost and the recording speed. It is possible, and high density can be realized.
  • phase difference ⁇ between pages may be controlled.
  • phase control learning (the process of step S604) may be performed each time a book is recorded, or may be performed only once when the optical recording medium 1 is mounted on the optical recording / reproducing apparatus 10.
  • the frequency of the adjustment is not limited.
  • the second embodiment is basically the same as the optical recording / reproducing device 10 according to the first embodiment, and will be described focusing on the differences.
  • the second embodiment is different from the first embodiment in that the position control of the optical recording medium 1 is performed for each mount of the optical recording medium 1 in the first embodiment, The point is that the position of the optical recording medium 1 is controlled for each page on which recording or reproduction is performed.
  • FIG. 13 is a diagram showing an example of an operation flow of data recording.
  • FIG. 13 shows an operation flow of data recording in the second embodiment, which corresponds to step S616 of the recording processing of the first embodiment.
  • the reference light angle is set for the page to be recorded (step S61601), and the position of the optical recording medium 1 is set at the position for each page determined in the phase control learning process (step S604). (Step S61602). Then, one page of data is recorded (step S61603), and a recording end determination (step S61604) is performed.
  • This recording end determination is the same as step S60404 of the phase control learning process in the first embodiment, but may be different.
  • step S61604 If the recording end is not determined in the recording end determination (step S61604) (“No” in step S61604), the controller 89 returns the control to step S61601. If it is determined that the recording has been completed (“Yes” in step S61604), the controller 89 advances the control to post cure (step S617).
  • the reference light angle is set for the page to be reproduced, and the position of the optical recording medium 1 is set to the position at the time of recording for each page. Play the data.
  • the position of the optical recording medium 1 is determined so that the inter-page phase difference can be controlled for each page.
  • the optical recording / reproducing apparatus As described above, by performing position control of the optical recording medium 1 for each page and performing recording and reproduction, the optical recording / reproducing apparatus according to the second embodiment provides an appropriate phase difference for each page and performs recording and reproduction. Alternatively, the reproduction quality can be improved.
  • the position control of the optical recording medium 1 is performed for each page.
  • the position control is performed for each predetermined number of pages (for example, every four pages). May be.
  • the third embodiment is an embodiment in which inter-page phase difference control by position control of the optical recording medium 1 for the purpose of reducing crosstalk is applied to a light guide plate 1210 using holography.
  • FIG. 14 is a diagram illustrating a configuration example of a light guide plate according to the third embodiment.
  • the light guide plate 1210 guides light from the input unit 1204 to the output unit 1206 when the incident light input to the input unit 1204 exits from the output unit 1206.
  • the input unit 1204 and the output unit 1206 are provided with multiplexed holograms.
  • the incident light applied to the total reflection unit 1205 is reflected and reaches a hologram provided in the output unit 1206.
  • the input unit 1204 diffracts the incident lights 1201 to 1203 to an angle that totally reflects the inside of the light guide plate 1210, and Numerals 1201 to 1203 propagate in the total reflection unit 1205, are supplied to the output unit 1206, become output lights 1207 to 1209, and output to the outside of the light guide plate 1210.
  • One hologram can diffract light with a limited angle and a limited wavelength. Therefore, by multiplexing the holograms, it is possible to increase the angle and wavelength of the light to be diffracted.
  • the holograms provided in the input unit 1204 and the output unit 1206 light incident on the light guide plate 1210 can be output to an arbitrary position at an arbitrary angle.
  • the light guide plate 1210 using holography when the incident lights 1201 to 1203 are diffracted by the input unit 1204, and when the output light 1206 becomes output lights 1207 to 1209 and is output to the outside of the light guide plate 1210, the light is adjacent to the light.
  • the problem is that crosstalk between pages from a hologram to be reproduced becomes a disturbance and is superimposed as in the case of adjacent pages in multiplex recording of the optical recording medium 1.
  • This problem can occur when the phase difference between multiplexed recorded holograms is not controlled.
  • the reproduction light causes unintended interference due to crosstalk between the holograms (for example, the "increasing interference" shown in FIG. 9A or the "increasing interference” shown in FIG. 9C). Interference), which leads to variations in playback intensity. This has the effect of deteriorating the image quality of the image displayed using the light guide plate.
  • the mechanism of the generation of the crosstalk is a phenomenon caused by the same principle as the crosstalk due to the page multiplexing of the optical recording medium 1.
  • the light guide plate 1210 according to the third embodiment also applies the same phase control as that of the relative position control of the optical recording medium 1 to the pickup 11 to the hologram.
  • An apparatus for manufacturing the light guide plate 1210 using holography and an operation for manufacturing a hologram by the apparatus are similar to the data recording operation according to the first embodiment and the second embodiment.
  • the light guide plate 1210 can be manufactured.
  • the rotation motor 50 may be changed to a mechanism that can fix the light guide plate 1210 during data recording.
  • the input unit 1204 A hologram that outputs the incident light beams 1201 to 1203 to be radiated to arbitrary positions and at an arbitrary angle and a hologram that forms the output unit 1206 can be manufactured.
  • each of the above-described configurations, functions, and the like may be realized by software control in which a processor performs an operation in accordance with a program that realizes each function.
  • Information such as programs, tables, and files for realizing each function is stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC (Integrated Circuit) card, an SD card, or a DVD.
  • a RAM Random Access Memory
  • CPU Central Processing Unit
  • control lines and information lines indicate those which are considered necessary for explanation, and do not necessarily indicate all control lines and information lines on the product. In fact, it may be considered that almost all components are interconnected.

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  • Optical Recording Or Reproduction (AREA)

Abstract

The present invention achieves high-speed recording while reducing the cost of a device relating to optical recording and reading. Provided is an optical recording device that records the interference pattern between signal light and reference light on an optical recording medium as a hologram in an angular multiplexing scheme using holography, said optical recording device including a position control unit capable of changing the mutual positional relationship between an optical recording device and an optical recording medium when recording the interference pattern. The position control unit changes the mutual positional relationship between the optical recording device and the optical recording medium to thereby record adjacent data with the phase difference created therebetween.

Description

光記録装置、導光板及び光記録方法Optical recording device, light guide plate and optical recording method
　本発明は、光記録装置、導光板及び光記録方法に関する。 The present invention relates to an optical recording device, a light guide plate, and an optical recording method.
　本技術分野の背景技術として、特開２０１７－１２６３９０号公報（特許文献１）がある。当該公報には、「ホログラフィを利用して光情報記録媒体に信号光と参照光との干渉パターンをホログラムとして多重記録する光情報記録装置において、レーザ光を出射する光源と、レーザ光を参照光と信号光に分離する光学素子と、参照光の光情報記録媒体への入射角度を制御する角度制御部と、記録時に信号光および参照光の少なくとも一つの位相を制御する位相制御部と、を備え、角度制御部は信号光の隣接ページの１ｓｔ　ｎｕｌｌの位置が固定されるように角度間隔を制御し、位相制御部は隣接ページ間の位相差が所定値となるように信号光または参照光の位相を制御する」と記載されている。 背景 As a background art in this technical field, there is JP-A-2017-126390 (Patent Document 1). The publication discloses a light source that emits laser light, a laser light source, and a reference light source. The optical information recording device multiplexes and records, as a hologram, an interference pattern between signal light and reference light on an optical information recording medium using holography. An optical element that separates the signal light into signal light, an angle control unit that controls the incident angle of the reference light to the optical information recording medium, and a phase control unit that controls at least one phase of the signal light and the reference light during recording. The angle control unit controls the angle interval so that the position of 1st @ null of the adjacent page of the signal light is fixed, and the phase control unit controls the signal light or the reference light so that the phase difference between the adjacent pages becomes a predetermined value. To control the phase ”.
特開２０１７－１２６３９０号公報JP 2017-126390 A
　上記特許文献１に記載された技術は、隣接ページ間のクロストーク低減のために位相制御部を備えるものであり、記録毎に同期して位相制御部を制御する必要がある。すなわち、書き込みのページ間のインターバルとして、参照光の角度変更の時間（３００マイクロ秒等）が設けられているが、その間に位相制御を終了させなければ、書き込みが遅延することとなる。これは、位相制御部を設けることで装置コストが増加するだけでなく、位相制御に必要な時間が書き込みのページ間のインターバルよりも長いと、記録速度低下の可能性が生じる。 The technique described in Patent Document 1 includes a phase control unit for reducing crosstalk between adjacent pages, and needs to control the phase control unit in synchronization with each recording. That is, a time (300 microseconds or the like) for changing the angle of the reference light is provided as an interval between pages of writing, but if the phase control is not completed during that time, writing will be delayed. This is because not only does the apparatus cost increase due to the provision of the phase control unit, but if the time required for the phase control is longer than the interval between the writing pages, there is a possibility that the recording speed may decrease.
　本発明の目的は、光記録および読み出しに関する装置のコストを減らしつつ、高速記録を実現することを目的とする。 目的 An object of the present invention is to realize high-speed recording while reducing the cost of an apparatus for optical recording and reading.
　本願は、上記課題の少なくとも一部を解決する手段を複数含んでいるが、その例を挙げるならば、以下のとおりである。上記課題を解決すべく、本発明の一態様に係る光記録装置は、ホログラフィを利用して光記録媒体に信号光と参照光との干渉パターンをホログラムとして角度多重方式で記録する光記録装置において、記録する際に上記光記録装置と上記光記録媒体の互いの位置関係を変化させることができる位置制御部を有し、上記位置制御部は、上記光記録装置と前記光記録媒体の互いの位置関係を変化させることにより隣接データ間で位相差を設けて記録する、ことを特徴とする。 Although the present application includes a plurality of means for solving at least a part of the above-described problems, examples thereof are as follows. In order to solve the above problems, an optical recording device according to one embodiment of the present invention is an optical recording device that records an interference pattern between signal light and reference light as a hologram on an optical recording medium using holography by an angle multiplexing method. Has a position control unit that can change the positional relationship between the optical recording device and the optical recording medium when recording, the position control unit, the optical recording device and the optical recording medium of each other It is characterized in that recording is performed with a phase difference provided between adjacent data by changing the positional relationship.
　本発明によれば、光記録および読み出しに関する装置のコストを減らしつつ、高速記録を実現することができる。具体的には、ホログラフィを用いた角度多重方式の記録方法において、記録密度を高めた記録を行う場合に、装置コストを大幅に増加させずに高速かつ良好な品質で記録可能な光記録装置とその方法、また良好な品質で記録した光記録媒体を提供することができる。上記した以外の課題、構成及び効果は、以下の実施形態の説明により明らかにされる。 According to the present invention, high-speed recording can be realized while reducing the cost of an apparatus for optical recording and reading. Specifically, in an angle multiplexing recording method using holography, when performing recording with increased recording density, an optical recording device capable of recording with high speed and good quality without significantly increasing the device cost. The method and an optical recording medium recorded with good quality can be provided. Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.
本発明に係る光記録再生装置の構成例を表す概略図FIG. 1 is a schematic diagram illustrating a configuration example of an optical recording / reproducing apparatus according to the present invention. ピックアップの構成例（記録時）を表す概略図Schematic diagram showing a configuration example of a pickup (at the time of recording) ピックアップの構成例（再生時）を表す概略図Schematic diagram showing a configuration example of a pickup (during playback) 準備処理の動作フロー例を示す図Diagram showing an operation flow example of the preparation process 記録処理の動作フロー例を示す図Diagram showing an example of an operation flow of a recording process 再生処理の動作フロー例を示す図Diagram showing an example of the operation flow of the reproduction process 媒体内における信号光と参照光の角度の定義を表す図Diagram showing the definition of the angle between the signal light and the reference light in the medium ページ間クロストークの例を示す模式図Schematic diagram showing an example of inter-page crosstalk ページ間位相差変化による再生光量の変化例を示す図A diagram showing an example of a change in the amount of reproduced light due to a change in a phase difference between pages. 光記録媒体の移動制御による位相制御例を示す概念図Conceptual diagram showing an example of phase control by movement control of an optical recording medium 光記録媒体の光軸方向の移動量とページ間位相差の余弦値との関係を示す図FIG. 4 is a diagram showing a relationship between an amount of movement of an optical recording medium in an optical axis direction and a cosine value of a phase difference between pages 位相制御学習処理の動作フロー例を示す図Diagram showing an operation flow example of the phase control learning process 第二の実施形態に係るデータ記録の動作フロー例を示す図FIG. 9 is a diagram illustrating an example of an operation flow of data recording according to the second embodiment. 第三の実施形態に係る導光板の構成例を示す図The figure which shows the example of a structure of the light-guide plate which concerns on 3rd Embodiment.
　以下、本発明に係る実施の形態を図面に基づいて説明する。なお、実施の形態を説明するための全図において、同一の部材には原則として同一の符号を付し、その繰り返しの説明は省略する。また、以下の実施の形態において、その構成要素（要素ステップ等も含む）は、特に明示した場合および原理的に明らかに必須であると考えられる場合等を除き、必ずしも必須のものではないことは言うまでもない。また、「Ａからなる」、「Ａよりなる」、「Ａを有する」、「Ａを含む」と言うときは、特にその要素のみである旨明示した場合等を除き、それ以外の要素を排除するものでないことは言うまでもない。同様に、以下の実施の形態において、構成要素等の形状、位置関係等に言及するときは、特に明示した場合および原理的に明らかにそうでないと考えられる場合等を除き、実質的にその形状等に近似または類似するもの等を含むものとする。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings for describing the embodiments, the same members are denoted by the same reference numerals in principle, and the repeated description thereof will be omitted. Also, in the following embodiments, the components (including element steps, etc.) are not necessarily essential unless otherwise specified and in cases where it is deemed essential in principle. Needless to say. In addition, when saying “consisting of A”, “consisting of A”, “having A”, and “including A”, other elements are excluded unless otherwise specified. Needless to say, it is not something to do. Similarly, in the following embodiments, when referring to the shapes, positional relationships, and the like of the constituent elements, the shapes are substantially the same unless otherwise specified and in cases where it is considered that it is not clearly apparent in principle. And the like.
　現在、青紫色半導体レーザを用いたＢｌｕ－ｒａｙ　Ｄｉｓｃ（登録商標）規格により、民生用においても１００ＧＢ（Ｇｉｇａ　Ｂｙｔｅ：ギガバイト）程度の記録密度を持つ光記録媒体の商品化が可能となっている。今後は、光記録媒体においても５００ＧＢを超える大容量化が望まれる。しかしながら、このような高密度を光記録媒体で実現するためには、従来の短波長化と対物レンズ高ＮＡ（Ｎｕｍｅｒｉｃａｌ　Ａｐｅｒｔｕｒｅ：開口数）化による高密度化技術とは異なる新しい方式による高密度化技術が必要と考えられている。 Currently, according to the Blu-ray Disc (registered trademark) standard using a blue-violet semiconductor laser, it is possible to commercialize an optical recording medium having a recording density of about 100 GB (Giga Byte: gigabyte) even for consumer use. In the future, it is desired to increase the capacity of optical recording media to over 500 GB. However, in order to realize such high density with an optical recording medium, it is necessary to increase the density by using a new method which is different from the conventional technique of increasing the wavelength by shortening the wavelength and increasing the NA of the objective lens (Numerical Aperture: numerical aperture). Technology is considered necessary.
　次世代のストレージ技術に関する研究が行われる中、ホログラフィを利用してデジタル情報を記録するホログラム記録技術が注目を集めている。ホログラフィを利用した光記録再生装置においては、多重時に制御するパラメータである角度あるいは空間距離を詰めて記録することで記録密度を高める場合、角度的あるいは空間的に近傍から再生された信号とのクロストーク成分が増大し、再生信号の品質が著しく劣化するため、クロストークを低減しなければならない課題がある。これはストレージに限定されず、ホログラフィを利用した多重記録であれば同様に生じる課題であり、例えばホログラフィを用いた導光板でも同様に生じる課題といえる。 While research on next-generation storage technology is being conducted, holographic recording technology, which uses holography to record digital information, is attracting attention. In an optical recording / reproducing apparatus using holography, when recording is performed by narrowing an angle or a spatial distance, which is a parameter controlled at the time of multiplexing, to increase a recording density, a cross with an angularly or spatially reproduced signal is used. Since the talk component is increased and the quality of the reproduced signal is significantly deteriorated, there is a problem that the crosstalk must be reduced. This is not limited to the storage, but is a problem that occurs similarly in the case of multiplex recording using holography. For example, it can be said that a problem also occurs in a light guide plate using holography.
　本発明に係る第１の実施形態について説明する。本発明は光記録装置として実施可能であるが、再生時の効果を含めて説明するため、光記録再生装置として説明するものとする。 <1> A first embodiment according to the present invention will be described. The present invention can be embodied as an optical recording apparatus, but will be described as an optical recording / reproducing apparatus for the sake of description including effects at the time of reproduction.
　図１は、本発明に係る光記録再生装置の構成例を表す概略図である。光記録再生装置１０は、ホログラフィを利用してデジタル情報を記録し、再生する光記録媒体の記録再生装置である。上述のとおり、光記録再生装置１０は、光記録媒体に情報を記録することと、情報が記録された光記録媒体から情報を再生することと、のいずれも実施可能であるが、いずれか一方のみを実施する装置であってもよい。 FIG. 1 is a schematic diagram illustrating a configuration example of an optical recording / reproducing apparatus according to the present invention. The optical recording / reproducing apparatus 10 is an optical recording medium recording / reproducing apparatus for recording and reproducing digital information using holography. As described above, the optical recording / reproducing apparatus 10 can perform both of recording information on an optical recording medium and reproducing information from the optical recording medium on which information is recorded. It may be a device that performs only the above.
　光記録再生装置１０は、入出力制御回路９０を介して外部制御装置９１と接続されている。記録する場合には、光記録再生装置１０は外部制御装置９１から記録する情報信号を入出力制御回路９０により受信する。再生する場合には、光記録再生装置１０は再生した情報信号を入出力制御回路９０により外部制御装置９１に送信する。 The optical recording / reproducing device 10 is connected to an external control device 91 via an input / output control circuit 90. When recording, the optical recording / reproducing device 10 receives an information signal to be recorded from the external control device 91 by the input / output control circuit 90. When reproducing, the optical recording / reproducing device 10 transmits the reproduced information signal to the external control device 91 by the input / output control circuit 90.
　光記録再生装置１０は、ピックアップ１１、再生用参照光光学系１２、キュア光学系１３、光記録媒体回転角度検出用光学系１４、及び回転モータ５０を備えており、光記録媒体１は回転モータ５０によって回転可能な構成となっている。 The optical recording / reproducing apparatus 10 includes a pickup 11, a reproduction reference light optical system 12, a cure optical system 13, an optical recording medium rotation angle detecting optical system 14, and a rotation motor 50. The structure is such that it can be rotated by 50.
　ピックアップ１１は、参照光と信号光とを光記録媒体１に出射してホログラフィを利用してデジタル情報を光記録媒体１に記録する役割を果たす。この際、記録する信号はコントローラ８９によって情報信号をページデータに変調する信号生成回路８６を介してピックアップ１１内の空間光変調器に送り込まれ、信号光は空間光変調器によって変調される。 The pickup 11 emits reference light and signal light to the optical recording medium 1 and records digital information on the optical recording medium 1 using holography. At this time, a signal to be recorded is sent to a spatial light modulator in the pickup 11 by a controller 89 via a signal generating circuit 86 for modulating an information signal into page data, and the signal light is modulated by the spatial light modulator.
　光記録媒体１に記録した情報を再生する場合は、ピックアップ１１から出射された参照光を記録時とは逆の向きに光記録媒体に入射させる光波を再生用参照光光学系１２にて生成する。再生用参照光によって再生される再生光をピックアップ１１内の光検出器によって検出し、信号処理回路８５によって信号を再生する。 When information recorded on the optical recording medium 1 is reproduced, the reproduction reference light optical system 12 generates a light wave that causes the reference light emitted from the pickup 11 to be incident on the optical recording medium in a direction opposite to that at the time of recording. . The reproduction light reproduced by the reproduction reference light is detected by the photodetector in the pickup 11, and the signal is reproduced by the signal processing circuit 85.
　光記録媒体１に照射する参照光と信号光の照射時間は、ピックアップ１１内のシャッタの開閉時間をコントローラ８９によってシャッタ制御回路８７を介して制御することで調整できる。 (4) The irradiation time of the reference light and the signal light applied to the optical recording medium 1 can be adjusted by controlling the opening and closing time of the shutter in the pickup 11 by the controller 89 via the shutter control circuit 87.
　キュア光学系１３は、光記録媒体１のプリキュアおよびポストキュアに用いる光ビームを生成する役割を果たす。プリキュアとは、光記録媒体１内の所望の位置に情報を記録する際、所望位置に参照光と信号光を照射する前に予め所定の光ビームを照射する前工程である。ポストキュアとは、光記録媒体１内の所望の位置に情報を記録した後、該所望の位置に追記不可能とするために所定の光ビームを照射する後工程である。 The 光学 cure optical system 13 has a role of generating a light beam used for pre-cure and post-cure of the optical recording medium 1. Precuring is a pre-process of irradiating a predetermined light beam before irradiating a reference light and a signal light to a desired position when recording information at a desired position in the optical recording medium 1. Post cure is a post-process in which information is recorded at a desired position in the optical recording medium 1 and then a predetermined light beam is irradiated to make it impossible to additionally record at the desired position.
　光記録媒体回転角度検出用光学系１４は、光記録媒体１の回転角度を検出するために用いられる。光記録媒体１を所定の回転角度に調整する場合は、光記録媒体回転角度検出用光学系１４によって回転角度に応じた信号を検出し、検出された信号を用いてコントローラ８９によって光記録媒体回転モータ制御回路８８を介して光記録媒体１の回転角度を制御する事ができる。 The optical recording medium rotation angle detecting optical system 14 is used for detecting the rotation angle of the optical recording medium 1. When the optical recording medium 1 is adjusted to a predetermined rotation angle, a signal corresponding to the rotation angle is detected by the optical recording medium rotation angle detecting optical system 14, and the controller 89 uses the detected signal to rotate the optical recording medium. The rotation angle of the optical recording medium 1 can be controlled via the motor control circuit 88.
　光源駆動回路８２からは所定の光源駆動電流がピックアップ１１、キュア光学系１３、光記録媒体回転角度検出用光学系１４内の光源に供給され、各々の光源からは所定の光量で光ビームを発光することができる。 A predetermined light source driving current is supplied from the light source driving circuit 82 to the light sources in the pickup 11, the cure optical system 13, and the optical recording medium rotation angle detecting optical system 14, and each light source emits a light beam with a predetermined light amount. can do.
　また、ピックアップ１１及びキュア光学系１３は、光記録媒体１の半径方向に位置をスライドできる機構が設けられており、アクセス制御回路８１を介して位置制御が行われる。 The pickup 11 and the cure optical system 13 are provided with a mechanism capable of sliding the position of the optical recording medium 1 in the radial direction, and the position is controlled via the access control circuit 81.
　ところで、ホログラフィの角度多重の原理を利用した記録技術は、参照光角度のずれに対する許容誤差が極めて小さくなる傾向がある。従って、ピックアップ１１内に、参照光角度のずれ量を検出する機構を設けて、サーボ信号生成回路８３にてサーボ制御用の信号を生成し、サーボ制御回路８４を介して該ずれ量を補正するためのサーボ機構を光記録再生装置１０内に備える。また、サーボ信号生成回路８３は、ピックアップ１１内の光検出器が検出する光量の合計値を生成することもできる。なお、ピックアップ１１、キュア光学系１３、光記録媒体回転角度検出用光学系１４は、いくつかの光学系構成または全ての光学系構成をひとつに纏めて簡素化しても構わない。 記録 By the way, the recording technique using the principle of angle multiplexing of holography tends to have an extremely small allowable error with respect to the deviation of the reference beam angle. Therefore, a mechanism for detecting the shift amount of the reference light angle is provided in the pickup 11, a servo control signal is generated by the servo signal generation circuit 83, and the shift amount is corrected via the servo control circuit 84. Servo mechanism is provided in the optical recording / reproducing apparatus 10. Further, the servo signal generation circuit 83 can also generate a total value of light amounts detected by a photodetector in the pickup 11. The pickup 11, the cure optical system 13, and the optical recording medium rotation angle detecting optical system 14 may be simplified by integrating some optical system configurations or all optical system configurations into one.
　また、光記録媒体位置制御回路１００は、光記録媒体１とピックアップ１１との距離を変更させるように回転モータ５０を移動させて光記録媒体１とピックアップ１１の相対位置を制御する事ができる。例えば、回転モータ５０の回転軸方向に回転モータ５０の位置を移動するステッピングモータを取り付けておき、光記録媒体位置制御回路１００はステッピングモータの動作を制御する。すなわち、光記録媒体位置制御回路１００は、記録する際に光記録装置であるピックアップ１１と、光記録媒体１の互いの位置関係を変化させることができる。なお、光記録媒体位置制御回路１００は、光記録媒体１のマウント時に位置関係を変化させることもできるし、より細かく、例えば第二の実施形態に示すようにページ書き込み毎に位置関係を変化させることもできる。 The optical recording medium position control circuit 100 can control the relative position between the optical recording medium 1 and the pickup 11 by moving the rotary motor 50 so as to change the distance between the optical recording medium 1 and the pickup 11. For example, a stepping motor for moving the position of the rotation motor 50 in the direction of the rotation axis of the rotation motor 50 is attached, and the optical recording medium position control circuit 100 controls the operation of the stepping motor. That is, the optical recording medium position control circuit 100 can change the positional relationship between the optical pickup device 11 and the optical recording medium 1 when recording. The optical recording medium position control circuit 100 can change the positional relationship when the optical recording medium 1 is mounted, or can change the positional relationship more finely, for example, every page writing as shown in the second embodiment. You can also.
　図２は、ピックアップの構成例（記録時）を表す概略図である。当該ピックアップ１１の構成例では、光記録再生装置１０におけるピックアップ１１の基本的な光学系構成の記録原理が示されている。 FIG. 2 is a schematic diagram illustrating a configuration example (at the time of recording) of the pickup. In the configuration example of the pickup 11, the recording principle of the basic optical system configuration of the pickup 11 in the optical recording / reproducing apparatus 10 is shown.
　光源３０１を出射した光ビームはコリメートレンズ３０２を透過し、シャッタ３０３に入射する。シャッタ３０３が開いている時は、光ビームはシャッタ３０３を通過した後、例えば２分の１波長板などで構成される光学素子３０４によってｐ偏光とｓ偏光の光量比が所望の比になるようになど偏光方向が制御される。その後、光ビームはＰＢＳ（Ｐｏｌａｒｉｚａｔｉｏｎ　Ｂｅａｍ　Ｓｐｌｉｔｔｅｒ）プリズム３０５に入射する。 光 The light beam emitted from the light source 301 passes through the collimator lens 302 and enters the shutter 303. When the shutter 303 is open, after the light beam passes through the shutter 303, the optical element 304 including, for example, a half-wave plate or the like causes the light amount ratio between the p-polarized light and the s-polarized light to be a desired ratio. The polarization direction is controlled. Thereafter, the light beam is incident on a PBS (Polarization Beam Splitter) prism 305.
　ＰＢＳプリズム３０５を透過した光ビームは、信号光３０６として働き、ビームエキスパンダ３０８によって光ビーム径が拡大された後、位相マスク３０９、リレーレンズ３１０、ＰＢＳプリズム３１１を透過して空間光変調器３１２に入射する。位相マスク３０９は、信号光の波面を意図的に乱すことで、対物レンズでの信号光集光時に、光量集中を緩和させる素子である。これにより、光記録媒体中の記録材料を局所的に消費することを低減することができる。 The light beam transmitted through the PBS prism 305 functions as a signal light 306, and after the light beam diameter is expanded by a beam expander 308, the light beam passes through a phase mask 309, a relay lens 310, and a PBS prism 311, and passes through a spatial light modulator 312. Incident on. The phase mask 309 is an element that intentionally disturbs the wavefront of the signal light so as to reduce the concentration of the light amount when the signal light is collected by the objective lens. This can reduce local consumption of the recording material in the optical recording medium.
　空間光変調器３１２によってページデータが付加された信号光３０６は、ＰＢＳプリズム３１１を反射し、リレーレンズ３１３ならびに空間フィルタ３１４を伝播する。その後、信号光３０６は対物レンズ３１５によって光記録媒体１に集光する。 The signal light 306 to which the page data is added by the spatial light modulator 312 is reflected by the PBS prism 311 and propagates through the relay lens 313 and the spatial filter 314. After that, the signal light 306 is focused on the optical recording medium 1 by the objective lens 315.
　一方、ＰＢＳプリズム３０５を反射した光ビームは参照光３０７として働き、偏光方向変換素子３１６によって記録時または再生時に応じて所定の偏光方向に設定された後、ミラー３１７ならびにミラー３１８を経由してガルバノミラー３１９に入射する。ガルバノミラー３１９は、アクチュエータ３２０によって角度を調整可能のため、レンズ３２１とレンズ３２２を通過した後に光記録媒体１に入射する参照光３０７の入射角度を、所望の角度に設定することができる。なお、参照光３０７の入射角度を設定するために、ガルバノミラーに代えて、参照光３０７の波面を変換する素子を用いても構わない。本明細書では、参照光３０７の角度は、例えば図示するように光記録媒体１に垂直な方向を０度として、図上の反時計回りを＋方向、時計回りを－方向と定義する。 On the other hand, the light beam reflected by the PBS prism 305 functions as the reference light 307, and is set to a predetermined polarization direction by the polarization direction conversion element 316 according to recording or reproduction, and then passes through the mirror 317 and the mirror 318. The light enters the mirror 319. Since the angle of the galvanomirror 319 can be adjusted by the actuator 320, the incident angle of the reference light 307 incident on the optical recording medium 1 after passing through the lenses 321 and 322 can be set to a desired angle. Note that an element that converts the wavefront of the reference light 307 may be used in place of the galvanomirror to set the incident angle of the reference light 307. In this specification, the angle of the reference beam 307 is defined as 0 degree in a direction perpendicular to the optical recording medium 1 as shown in the figure, a counterclockwise direction in the figure is defined as a positive direction, and a clockwise direction is defined as a negative direction.
　このように信号光３０６と参照光３０７とを光記録媒体１上において、所定の角度で互いに重ね合うように入射させることで、光記録媒体１内には干渉縞パターンが形成され、このパターンを光記録媒体１に書き込むことで情報を記録する。また、ガルバノミラー３１９によって光記録媒体１に入射する参照光の入射角度を変化させることができるため、少なくとも互いに異なる２つの角度により参照光と信号光とを干渉させることで、同一領域に角度多重による記録が可能である。 By causing the signal light 306 and the reference light 307 to be incident on the optical recording medium 1 so as to overlap each other at a predetermined angle in this manner, an interference fringe pattern is formed in the optical recording medium 1, and this pattern is Information is recorded by writing to the recording medium 1. Further, since the incident angle of the reference light incident on the optical recording medium 1 can be changed by the galvanomirror 319, the reference light and the signal light are caused to interfere with each other at least at two different angles, so that angle multiplexing is performed in the same area. Recording is possible.
　以降、同じ領域に少なくとも互いに異なる２つの参照光角度で記録されたホログラムにおいて、各参照光角度に対応したホログラムをページと呼び、同領域に角度多重されたページの集合をブックと呼ぶことにする。 Hereinafter, among holograms recorded at least at two different reference light angles in the same area, a hologram corresponding to each reference light angle is referred to as a page, and a set of pages angularly multiplexed in the same area is referred to as a book. .
　図３は、ピックアップの構成例（再生時）を表す概略図である。当該ピックアップ１１の構成例では、光記録再生装置１０におけるピックアップ１１の基本的な光学系構成の再生原理を示したものである。 FIG. 3 is a schematic diagram illustrating a configuration example (during reproduction) of the pickup. In the configuration example of the pickup 11, the reproduction principle of the basic optical system configuration of the pickup 11 in the optical recording / reproduction device 10 is shown.
　光記録媒体１に記録したページデータを再生する場合は、上述したように参照光３０７を光記録媒体１に入射し、光記録媒体１を透過した光ビームを、アクチュエータ３２３によって角度調整可能なガルバノミラー３２４にて反射させることで、その再生用参照光を生成する。 When reproducing the page data recorded on the optical recording medium 1, the reference beam 307 is incident on the optical recording medium 1 as described above, and the light beam transmitted through the optical recording medium 1 is subjected to the angle adjustment by the actuator 323. By being reflected by the mirror 324, the reference light for reproduction is generated.
　この再生用参照光によって再生された再生光は、対物レンズ３１５、リレーレンズ３１３ならびに空間フィルタ３１４を伝播する。その後、再生光はＰＢＳプリズム３１１を透過して光検出器３２５に入射し、記録したページデータを再生することができる。光検出器３２５としては例えばＣＭＯＳ（Ｃｏｍｐｌｅｍｅｎｔａｒｙ　Ｍｅｔａｌ　Ｏｘｉｄｅ　Ｓｅｍｉｃｏｎｄｕｃｔｏｒ：相補性金属酸化膜半導体）イメージセンサーやＣＣＤ（Ｃｈａｒｇｅ　Ｃｏｕｐｌｅｄ　Ｄｅｖｉｃｅ：電荷結合素子）イメージセンサーなどの撮像素子を用いることができるが、ページデータを再生可能であれば、どのような素子であっても構わない。 再生 The reproduction light reproduced by the reproduction reference light propagates through the objective lens 315, the relay lens 313, and the spatial filter 314. After that, the reproduction light passes through the PBS prism 311 and enters the photodetector 325, so that the recorded page data can be reproduced. As the photodetector 325, for example, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor can be used. Any element can be used as long as it can be reproduced.
　図４は、準備処理の動作フロー例を示す図である。ここでは、特にホログラフィを利用した記録再生に関するフローを説明する。 FIG. 4 is a diagram showing an example of an operation flow of the preparation process. Here, a flow relating to recording / reproduction using holography will be particularly described.
　図４の準備処理は、光記録再生装置１０に光記録媒体１が挿入された後、記録または再生の準備が完了するまでの動作フローを示している。 4 shows the operation flow from the insertion of the optical recording medium 1 into the optical recording / reproducing apparatus 10 to the completion of the preparation for recording or reproduction.
　まず、記録媒体が挿入されると、光記録再生装置１０は、例えば挿入された媒体が光を受光する入力部と、光を出力する出力部と、光を全反射する全反射部と、を備えホログラフィを利用して情報を記録または再生する光記録媒体１であるかどうかの判別を行う（ステップＳ６０１）。 First, when a recording medium is inserted, the optical recording / reproducing device 10 includes, for example, an input unit that receives light from the inserted medium, an output unit that outputs light, and a total reflection unit that totally reflects light. It is determined whether or not the optical recording medium 1 is used to record or reproduce information by using provided holography (step S601).
　媒体判別の結果、挿入された媒体が光を受光する入力部と、光を出力する出力部と、光を全反射する全反射部と、を備えホログラフィを利用して情報を記録または再生する光記録媒体１であると判断されると、光記録再生装置１０は光記録媒体１に設けられたコントロールデータを読み出す（ステップＳ６０２）。例えば、光記録再生装置１０は、光記録媒体１に関する情報や、記録や再生時における各種設定条件に関する情報を取得する。 As a result of the medium discrimination, the inserted medium has an input unit for receiving light, an output unit for outputting light, and a total reflection unit for totally reflecting light, and a light for recording or reproducing information using holography. If it is determined that the medium is the recording medium 1, the optical recording / reproducing apparatus 10 reads the control data provided on the optical recording medium 1 (Step S602). For example, the optical recording / reproducing device 10 acquires information on the optical recording medium 1 and information on various setting conditions at the time of recording and reproduction.
　コントロールデータの読み出し後は、光記録再生装置１０は、コントロールデータに応じた各種調整やピックアップ１１に関わる学習処理（ステップＳ６０３）を行う。また、光記録再生装置１０は、ページ間クロストーク低減のための位相制御学習（ステップＳ６０４）を行う。そして、光記録再生装置１０は、記録または再生の準備を完了させる（ステップＳ６０５）。ページ間クロストーク低減のための位相制御学習（ステップＳ６０４）の詳細な動作は後述する。 After reading out the control data, the optical recording / reproducing apparatus 10 performs various adjustments according to the control data and learning processing relating to the pickup 11 (step S603). Further, the optical recording / reproducing device 10 performs phase control learning for reducing inter-page crosstalk (step S604). Then, the optical recording / reproducing device 10 completes the preparation for recording or reproduction (step S605). The detailed operation of the phase control learning (step S604) for reducing inter-page crosstalk will be described later.
　図５は、記録処理の動作フロー例を示す図である。ここでは、特にホログラフィを利用した記録に関するフローを説明する。 FIG. 5 is a diagram showing an example of an operation flow of a recording process. Here, a flow related to recording using holography will be particularly described.
　図５の記録処理は、準備完了状態から光記録媒体１に情報を記録するまでの動作フローを示している。 (5) The recording process of FIG. 5 shows an operation flow from the ready state to recording information on the optical recording medium 1.
　まず、入出力制御回路９０は、記録する情報を受信（ステップＳ６１１）して、信号生成回路８６に送る。そして、光記録媒体１にページを高品質に記録できるように、コントローラ８９は必要に応じて、各種記録用学習処理を事前に行う（ステップＳ６１２）。例えば、コントローラ８９は、既存の技術である光源３０１のパワー最適化や、シャッタ３０３による露光時間の最適化等の各種記録用学習処理を事前に行う。 First, the input / output control circuit 90 receives the information to be recorded (step S611) and sends it to the signal generation circuit 86. Then, the controller 89 performs various recording learning processes in advance as needed so that pages can be recorded on the optical recording medium 1 with high quality (step S612). For example, the controller 89 performs various recording learning processes such as power optimization of the light source 301 and optimization of the exposure time by the shutter 303, which are existing technologies, in advance.
　その後、コントローラ８９は、シーク動作を行う（ステップＳ６１３）。具体的には、コントローラ８９は、アクセス制御回路８１を制御して、ピックアップ１１ならびにキュア光学系１３の位置を光記録媒体１の所定の位置に位置づける。光記録媒体１がアドレス情報を持つ場合には、コントローラ８９は、アドレス情報を再生し、目的の位置に位置づけされているか確認し、目的の位置に配置されていなければ、所定の位置とのずれ量を算出し、再度位置づけを行う動作を繰り返す。 Thereafter, the controller 89 performs a seek operation (step S613). Specifically, the controller 89 controls the access control circuit 81 to position the pickup 11 and the cure optical system 13 at predetermined positions on the optical recording medium 1. If the optical recording medium 1 has address information, the controller 89 reproduces the address information and checks whether the address information is positioned at the target position. If not, the controller 89 shifts from the predetermined position. The operation of calculating the amount and repositioning is repeated.
　そして、アクセス制御回路８１は、キュア光学系１３から出射する光ビームを用いて所定の領域をプリキュアする（ステップＳ６１４）。プリキュア後、信号生成回路８６は記録する情報を２次元データに変換する２次元データ生成処理を行う（ステップＳ６１５）。 Then, the access control circuit 81 precures a predetermined area using the light beam emitted from the cure optical system 13 (step S614). After the pre-curing, the signal generation circuit 86 performs a two-dimensional data generation process of converting the information to be recorded into two-dimensional data (step S615).
　そして、信号生成回路８６は、生成した２次元データをピックアップ１１内の空間光変調器３１２に送信し、ピックアップ１１から出射する参照光と信号光とを用いて光記録媒体１に２次元データとして情報を記録する（ステップＳ６１６）。アクセス制御回路８１は、２次元データを記録した後は、キュア光学系１３から出射する光ビームを用いてポストキュアを行う（ステップＳ６１７）。なお、アクセス制御回路８１は、必要に応じて記録した２次元データに誤りがないか、ベリファイしても構わない。 Then, the signal generation circuit 86 transmits the generated two-dimensional data to the spatial light modulator 312 in the pickup 11 and uses the reference light and the signal light emitted from the pickup 11 as two-dimensional data on the optical recording medium 1. Information is recorded (step S616). After recording the two-dimensional data, the access control circuit 81 performs post cure using the light beam emitted from the cure optical system 13 (step S617). The access control circuit 81 may verify the recorded two-dimensional data for errors as necessary.
　図６は、再生処理の動作フロー例を示す図である。ここでは、特にホログラフィを利用した再生に関するフローを説明する。 FIG. 6 is a diagram showing an example of an operation flow of the reproduction process. Here, a flow relating to reproduction using holography will be particularly described.
　図６の再生処理は、準備完了状態から光記録媒体１に記録した情報を再生するまでの動作フローを示している。 (6) The reproduction process in FIG. 6 shows an operation flow from the preparation completion state to the reproduction of information recorded on the optical recording medium 1.
　まず、コントローラ８９は、シーク動作を行う（ステップＳ６２１）。具体的には、コントローラ８９は、アクセス制御回路８１を制御して、ピックアップ１１ならびに再生用参照光光学系１２の位置を光記録媒体１の所定の位置に位置づける。光記録媒体１が物理的に物理アドレス情報を持つ場合には、コントローラ８９は、物理アドレス情報を再生し、目的の位置に位置づけされているか確認し、目的の位置に配置されていなければ、所定の位置とのずれ量を算出し、再度位置づけする動作を繰り返す。光記録媒体１が物理的に物理アドレス情報を持たない場合には、コントローラ８９は、光記録媒体１の回転角とピックアップ１１の半径方向位置を、光記録媒体回転角度検出用光学系１４とアクセス制御回路８１を用いて検出し、目的の位置とのずれ量を算出し、ずれ量が減る方向にピックアップ１１を動作させることで所定の位置づけを行う。 First, the controller 89 performs a seek operation (step S621). Specifically, the controller 89 controls the access control circuit 81 to position the pickup 11 and the reproduction reference light optical system 12 at predetermined positions on the optical recording medium 1. When the optical recording medium 1 physically has physical address information, the controller 89 reproduces the physical address information and checks whether the physical address information is positioned at a target position. The amount of deviation from the position is calculated, and the operation of repositioning is repeated. When the optical recording medium 1 does not physically have the physical address information, the controller 89 determines the rotation angle of the optical recording medium 1 and the radial position of the pickup 11 by accessing the optical recording medium rotation angle detecting optical system 14. The detection is performed using the control circuit 81, the amount of deviation from the target position is calculated, and the pickup 11 is operated in a direction in which the amount of deviation is reduced to perform predetermined positioning.
　そして、ピックアップ１１が参照光を出射し、光記録媒体１に記録された情報である再生画像データを信号処理回路８５にて取得し、再生画像データ内の２次元データヘッダ部の再生の後に、データを再生する（ステップＳ６２２）。そして、信号処理回路８５が再生したデータを入出力制御回路９０が外部制御装置９１へ送信する（ステップＳ６２３）。なお、２次元データヘッダ部のデータ再生の結果として目標とする再生画像データと識別されない場合においては、目標とは異なる再生画像データを検出しているおそれがあるので、データの送信は行わずに中止するか、ステップＳ６２１の処理から再度実行する。 Then, the pickup 11 emits the reference light, the reproduced image data, which is the information recorded on the optical recording medium 1, is acquired by the signal processing circuit 85, and after the reproduction of the two-dimensional data header portion in the reproduced image data, The data is reproduced (step S622). Then, the input / output control circuit 90 transmits the data reproduced by the signal processing circuit 85 to the external control device 91 (step S623). If the target reproduced image data is not identified as a result of the data reproduction of the two-dimensional data header portion, the reproduced image data different from the target may be detected. The processing is stopped or the processing is executed again from the processing in step S621.
　以上が、光記録再生装置１０に光記録媒体が挿入されてから、準備処理を行い、記録または再生処理を行う流れである。 The above is the flow of performing the preparatory process and performing the recording or reproducing process after the optical recording medium is inserted into the optical recording and reproducing device 10.
　ここで、ページ間クロストークの影響の説明に先立ち、再生光の強度と位相について説明する。角度多重を用いた場合、再生光強度すなわち、回折光量は、数１により表すことができる。 Here, prior to the description of the influence of inter-page crosstalk, the intensity and phase of the reproduction light will be described. When angle multiplexing is used, the intensity of the reproduction light, that is, the amount of diffracted light can be expressed by Equation 1.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　ここで、ｎは光記録媒体１の屈折率、Ｌは光記録媒体１の記録層の厚み、λは信号光３０６と参照光３０７の波長、θＭＲＳは信号光３０６と参照光３０７が成す角度、θＭＳは光記録媒体１の法線に対する信号光３０６の角度、ΔθＭＲは記録時に対する再生時の角度ずれである。なお、数１における角度は光記録媒体１の媒体内における角度であり、光記録媒体１の屈折率の影響を受ける。θＭＲを光記録媒体１の法線に対する参照光３０７の角度として、図７に光記録媒体１に対するθＭＲＳ、θＭＳ、θＭＲの関係を示す。 Here, n is the refractive index of the optical recording medium 1, L is the thickness of the recording layer of the optical recording medium 1, λ is the wavelength of the signal light 306 and the reference light 307, and θ MRS is the angle formed by the signal light 306 and the reference light 307. , Θ MS is the angle of the signal light 306 with respect to the normal to the optical recording medium 1, and Δθ MR is the angle shift during reproduction with respect to recording. Note that the angle in Expression 1 is an angle in the optical recording medium 1 and is affected by the refractive index of the optical recording medium 1. As the angle of the reference beam 307 to theta MR with respect to the normal line of the optical recording medium 1, shown theta MRS with respect to the optical recording medium 1, theta MS, the relationship between theta MR in Fig.
　図７は、媒体内における信号光と参照光の角度の定義を表す図である。各角度については、上述のとおりである。また、θＭＲＳ、θＭＳ、θＭＲ、ΔθＭＲに対応する空気中での角度をそれぞれθＡＲＳ、θＡＳ、θＡＲ、ΔθＡＲとする。次に、隣接ページからのクロストークの影響について、図８を用いて説明する。 FIG. 7 is a diagram illustrating the definition of the angle between the signal light and the reference light in the medium. Each angle is as described above. Also, angles in the air corresponding to θ MRS , θ MS , θ MR , and Δθ MR are set to θ ARS , θ AS , θ AR , and Δθ AR , respectively. Next, the influence of crosstalk from an adjacent page will be described with reference to FIG.
　図８は、ページ間クロストークの例を示す模式図である。具体的には、隣接ページからのクロストークの例を示す模式図である。隣接ページからのクロストークとは、再生の対象としているページデータに対して異なるページから漏れこんでくる不要な信号成分をいう。図８の模式図では、横軸は参照光角度を、縦軸は再生光強度を表すグラフが示されている。例えば第ｎ番目のページを再生する為に最適な参照光角度θnにおいて再生した場合、隣接ページである第（ｎ＋１）番目のページも再生される。図示した第ｎページ、第（ｎ＋１）ページの２つのページデータが再生される例においては、全体の再生光強度は、数２で表される。 FIG. 8 is a schematic diagram showing an example of inter-page crosstalk. Specifically, it is a schematic diagram illustrating an example of crosstalk from an adjacent page. Crosstalk from an adjacent page means an unnecessary signal component that leaks from a different page with respect to page data to be reproduced. In the schematic diagram of FIG. 8, the horizontal axis shows a reference light angle, and the vertical axis shows a reproduction light intensity. For example, when reproducing at the optimum reference light angle θn for reproducing the n-th page, the (n + 1) -th page which is an adjacent page is also reproduced. In the example in which the illustrated two page data of the n-th page and the (n + 1) -th page are reproduced, the entire reproduced light intensity is represented by Expression 2.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、Ｉは参照光角度θｎにおける再生光量、Ｅｎは第ｎページの再生光の振幅、Ｅｎ＋１は第（ｎ＋１）ページの再生光の振幅、φは第ｎページと第（ｎ＋１）ページの記録時の位相差である。ここで、第ｎページのデータを再生する場合を想定した場合、第１項の｜Ｅｎ｜２が所望の再生信号であり、第２項の｜Ｅｎ＋１｜２は、不要なクロストーク成分（ノイズ成分）である。本例においては、参照光角度θｎで再生している為、｜Ｅｎ｜＞＞｜Ｅｎ＋１｜の関係があり、第２項は第１項に比べて非常に小さい。第３項の２｜Ｅｎ｜｜Ｅｎ＋１｜ｃｏｓφは、｜Ｅｎ｜の因子が含まれていることもあり、第２項に比べて比較的大きな光量となり得る。φ＝０のときは、第３項は正となり、｜Ｅｎ｜を増幅して信号品質を向上させることができ、φ＝１／２×πもしくはφ＝３／２×πの時は｜Ｅｎ＋１｜のクロストークを軽減して信号品質を向上させることができる。ページ間位相差φの変化による再生光量Ｉの変化の例を図９に示す。 Here, I is the reference beam angle θn in the reproducing light amount, E n is the amplitude of the reproduction light of the n pages, E n + 1 (n + 1) -th amplitude of the pages of the reproduction light, phi is a first n pages (n + 1) th page Is the phase difference at the time of recording. Here, assuming that the data of the n-th page is reproduced, | E n | 2 of the first term is a desired reproduction signal, and | E n + 1 | 2 of the second term is an unnecessary crosstalk component. (Noise component). In this example, since the reproduction is performed at the reference light angle θn, there is a relation of | E n | >> | E n + 1 |, and the second term is much smaller than the first term. The third term 2 | E n || E n + 1 | cos φ may include a factor of | E n | and may have a relatively large light amount as compared to the second term. When φ = 0, the third term is positive, and | E n | can be amplified to improve signal quality. When φ =＝ × π or φ = 3/2 × π, | E n + 1 | crosstalk can be reduced to improve signal quality. FIG. 9 shows an example of a change in the reproduction light amount I due to a change in the inter-page phase difference φ.
　図９は、ページ間位相差変化による再生光量の変化例を示す図である。再生光量９０１は第ｎページの再生光量｜Ｅｎ｜、再生光量９０２は第（ｎ＋１）ページの再生光量｜Ｅｎ＋１｜、再生光量９００は第ｎページと第（ｎ＋１）ページから得られた全体の再生光量Ｉを示す。 FIG. 9 is a diagram illustrating an example of a change in the reproduction light amount due to a change in the inter-page phase difference. The reproduction light amount 901 is the reproduction light amount | E n | of the nth page, the reproduction light amount 902 is the reproduction light amount | E n + 1 | of the (n + 1) th page, and the reproduction light amount 900 is the entirety obtained from the nth and (n + 1) th pages. Is shown.
　図９の（ａ）では、位相差φが０の時の再生光量を示し、図９の（ｂ）では位相差φが１／２×πの時の再生光量を示し、図９の（ｃ）では位相差φがπの時の再生光量を示す。位相差φが０である場合の図９の（ａ）の例では、数２の第３項が正の値となるため、再生光量Ｉ（９００）は大きく増幅する。 9A shows the reproduction light amount when the phase difference φ is 0, FIG. 9B shows the reproduction light amount when the phase difference φ is 1/2 × π, and FIG. ) Shows the reproduction light amount when the phase difference φ is π. In the example of FIG. 9A where the phase difference φ is 0, since the third term of Expression 2 is a positive value, the reproduction light amount I (900) is greatly amplified.
　位相差φが１／２×πである図９の（ｂ）の例では、数２の第３項が０となる。この場合、再生光量Ｉ９００は数２における所望の再生信号｜Ｅｎ｜２と、不要なクロストーク成分である｜Ｅｎ＋１｜２との和となるが、前記記載の通り｜Ｅｎ｜＞＞｜Ｅｎ＋１｜の関係があって第２項は第１項に比べて非常に小さいため、再生光量Ｉの凡そは所望の再生信号｜Ｅｎ｜２の成分から構成され、良質な再生信号を得ることができる。 In the example of FIG. 9B where the phase difference φ is １ ／ × π, the third term of Expression 2 is 0. In this case, the reproduction light amount I900 is the sum of the desired reproduction signal | E n | 2 in Expression 2 and | E n + 1 | 2 that is an unnecessary crosstalk component. As described above, | E n | >> since the second term there is a relationship is very small compared to the first term, approximate reproducing light quantity I is desired reproduction signal | | | E n + 1 E n | is composed of two components, a high-quality reproduction signal Obtainable.
　位相差φがπである図９の（ｃ）の例では、数２の第３項が負の値となるため、再生光量Ｉ９００は減衰する。このように位相差φによって再生光量I９００は大きく変化し、例えば、再生光量Ｉ９００の極大値９０３と極大値９０４や半値幅９０５と半値幅９０６により再生光量I９００の波形を特徴づけ、隣接ページとの位相差と関連付けることで、ページ間の位相差を取得できる。ただし、再生光量I９００と隣接ページとの位相差に関する特徴づけの手法はこれらに限定されない。例えば、極大値の光量に限られず、極大値の数（再生光量Ｉ９００のグラフ上で、上昇から下降に移行する点の数）に応じて隣接ページとの位相差を関連付けるものであってもよい。 In the example of FIG. 9C where the phase difference φ is π, the third term of Expression 2 has a negative value, and therefore the reproduction light amount I900 is attenuated. As described above, the reproduction light amount I900 greatly changes depending on the phase difference φ. For example, the waveform of the reproduction light amount I900 is characterized by the maximum value 903 and the maximum value 904 of the reproduction light amount I900 and the half width 905 and the half width 906. By associating with the phase difference, the phase difference between pages can be obtained. However, the method of characterizing the phase difference between the reproduction light amount I900 and the adjacent page is not limited to these. For example, the phase difference with the adjacent page may be associated with not only the maximum light amount but also the number of the maximum value (the number of transition points from rising to falling on the graph of the reproduction light amount I900). .
　図１０は、光記録媒体の移動制御による位相制御例を示す概念図である。すなわち、図１０に示した概念図は、光記録媒体位置の制御によって異なるページ間位相差を与える例である。この仕組みについて、以下に説明する。 FIG. 10 is a conceptual diagram showing an example of phase control by movement control of an optical recording medium. That is, the conceptual diagram shown in FIG. 10 is an example in which different inter-page phase differences are given by controlling the position of the optical recording medium. This mechanism will be described below.
　参照光１０２の回転中心であるピボット１０３の位置は光記録媒体１をピックアップ１１に近づけるか遠ざける方向に移動させることによって、相対的に光記録媒体１上の位置がずれる。つまり、第ｎページの記録時に設定する参照光角度の参照光の任意の位相１０４と、第（ｎ＋１）ページの記録時の参照光角度の参照光の任意の位相１０５からピボット１０３までの各光路長は、光記録媒体１もしくはピックアップ１１を移動させることで変化するといえる。 The position of the pivot 103, which is the center of rotation of the reference light 102, is relatively shifted on the optical recording medium 1 by moving the optical recording medium 1 closer to or away from the pickup 11. That is, each optical path from the arbitrary phase 104 of the reference light at the reference light angle set at the time of recording the n-th page and the arbitrary phase 105 of the reference light at the reference light angle at the time of recording the (n + 1) page to the pivot 103 It can be said that the length changes by moving the optical recording medium 1 or the pickup 11.
　ここで、光記録媒体１の移動前後の位相１０４は移動前後で同位相であり、同様に光記録媒体１の移動前後の位相１０５は移動前後で同位相である。光記録媒体１を移動させることで、第ｎページの記録時に設定する参照光角度の参照光の任意の位相１０４と、第（ｎ＋１）ページの記録時の参照光角度の参照光の任意の位相１０５からピボット１０３までの各光路長は変化するため、光記録媒体１を移動させる前の位相１０４からピボット１０３までの光路長と位相１０５からピボット１０３までの光路長との差（数３）は、光記録媒体１を移動させた後の位相１０４からピボット１０３までの光路長と位相１０５からピボット１０３までの光路長との差（数４）とは異なる。 Here, the phase 104 before and after the movement of the optical recording medium 1 is the same before and after the movement, and similarly, the phase 105 before and after the movement of the optical recording medium 1 is the same before and after the movement. By moving the optical recording medium 1, an arbitrary phase 104 of the reference light at the reference light angle set at the time of recording the nth page and an arbitrary phase of the reference light at the reference light angle at the time of recording the (n + 1) th page Since each optical path length from 105 to the pivot 103 changes, the difference (Equation 3) between the optical path length from the phase 104 to the pivot 103 and the optical path length from the phase 105 to the pivot 103 before moving the optical recording medium 1 is The difference (Equation 4) between the optical path length from the phase 104 to the pivot 103 after moving the optical recording medium 1 and the optical path length from the phase 105 to the pivot 103 is different.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　このため、光記録媒体１の移動前後で、ピボット１０３での第ｎページと第（ｎ＋１）ページのページ間位相差は異なるといえる（数５参照）。 た め Therefore, it can be said that the phase difference between the n-th page and the (n + 1) -th page at the pivot 103 before and after the movement of the optical recording medium 1 is different (see Equation 5).
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　図１１は、光記録媒体の光軸方向の移動量とページ間位相差の余弦値との関係を示す図である。すなわち、図１１は、光記録媒体１のフォーカス位置８０１を基準に、光記録媒体１のフォーカス方向の移動量とページ間位相差の余弦値との関係の例である。光記録媒体１とピックアップ１１との距離が小さくなる方向を光記録媒体１の正の移動量とし、光記録媒体１とピックアップ１１との距離が遠くなる方向を光記録媒体１の負の移動量とする。光記録媒体１の移動量、すなわちデフォーカス量に応じて光路長の差が発生するため、ページ間位相差の余弦値は変化し、数２で示す回折光量は図９のような変化をする。図１２に、ページ間クロストーク低減のための位相制御学習（ステップＳ６０４）の動作フローの実施例を示す。 FIG. 11 is a diagram showing the relationship between the amount of movement of the optical recording medium in the optical axis direction and the cosine value of the inter-page phase difference. That is, FIG. 11 is an example of the relationship between the amount of movement of the optical recording medium 1 in the focus direction and the cosine value of the inter-page phase difference based on the focus position 801 of the optical recording medium 1. The direction in which the distance between the optical recording medium 1 and the pickup 11 decreases becomes the positive movement amount of the optical recording medium 1, and the direction in which the distance between the optical recording medium 1 and the pickup 11 increases becomes the negative movement amount of the optical recording medium 1. And Since a difference in the optical path length occurs according to the moving amount of the optical recording medium 1, that is, the defocus amount, the cosine value of the inter-page phase difference changes, and the amount of diffracted light shown by Expression 2 changes as shown in FIG. . FIG. 12 shows an example of an operation flow of the phase control learning (step S604) for reducing inter-page crosstalk.
　図１２は、位相制御学習処理の動作フロー例を示す図である。まず、サーボ信号生成回路８３はサーボ制御用の信号を生成し、サーボ制御回路８４を介して記録ページに参照光の角度を記録ページの進度に応じて所定の角度に設定する（ステップＳ６０４０１）。 FIG. 12 is a diagram illustrating an example of an operation flow of the phase control learning process. First, the servo signal generation circuit 83 generates a signal for servo control, and sets the angle of the reference beam on the recording page to a predetermined angle via the servo control circuit 84 in accordance with the progress of the recording page (step S60401).
　そして、光記録媒体位置制御回路１００は、記録する際の光記録媒体１の光軸方向の位置、すなわちピックアップ１１との距離を設定する（ステップＳ６０４０２）。この際、記録前の位相制御学習において既に記録した際の光記録媒体１の位置とは異なる位置に光記録媒体１を設定する。具体的には、光記録媒体位置制御回路１００は、光記録媒体１とピックアップ１１との距離を変更させるように回転モータ５０を移動させて光記録媒体１とピックアップ１１の相対位置を、記録時の光記録媒体１の位置とは異なる相対位置になるよう制御する。 Then, the optical recording medium position control circuit 100 sets the position of the optical recording medium 1 in the optical axis direction at the time of recording, that is, the distance from the pickup 11 (step S60402). At this time, the optical recording medium 1 is set at a position different from the position of the optical recording medium 1 already recorded in the phase control learning before recording. Specifically, the optical recording medium position control circuit 100 moves the rotary motor 50 so as to change the distance between the optical recording medium 1 and the pickup 11 and determines the relative position between the optical recording medium 1 and the pickup 11 during recording. Is controlled to be a relative position different from the position of the optical recording medium 1.
　そして、ピックアップ１１は、ページ記録を実施する（ステップＳ６０４０３）。そして、サーボ信号生成回路８３は、ピックアップ１１内の光検出器が検出する光量の合計値を計算し、図９（a）、図９（ｂ）、図９（ｃ）に示すような３つの回折光量のパターンの調整記録（学習用のホログラム作成）を実施できたか否かにより、調整記録を終了するか否かを判定する（ステップＳ６０４０４）。つまり、サーボ信号生成回路８３は、ページ間位相差を判断可能な範囲で調整記録を実施できたか否かを判断するといえる。なお、これに限られず、調整記録終了の判定は、光記録媒体１が予め定められた位置に達した場合に終了しても良いし、予め定められた記録領域にページ記録が達した場合に終了しても良く、その判定基準は上述の判定方法に限定されない。 Then, the pickup 11 performs page recording (step S60403). Then, the servo signal generation circuit 83 calculates the total value of the light amounts detected by the photodetectors in the pickup 11, and calculates the three values as shown in FIGS. 9 (a), 9 (b), and 9 (c). It is determined whether to end the adjustment recording based on whether or not the adjustment recording of the pattern of the diffracted light amount (production of the hologram for learning) has been performed (step S60404). That is, it can be said that the servo signal generation circuit 83 determines whether or not the adjustment recording has been performed within a range in which the inter-page phase difference can be determined. However, the present invention is not limited to this. The determination of the end of the adjustment recording may be terminated when the optical recording medium 1 reaches a predetermined position, or when the page recording reaches a predetermined recording area. The determination may be terminated, and the criterion is not limited to the above-described determination method.
　調整記録が終了していないと判定された場合（ステップＳ６０４０４にて「Ｎｏ」の場合）には、コントローラ８９は、ステップＳ６０４０１の処理に制御を戻す。調整記録が終了したと判定された場合（ステップＳ６０４０４にて「Ｙｅｓ」の場合）には、コントローラ８９は、学習用ホログラムの回折光量の取得を行う（ステップＳ６０４０５）。具体的には、コントローラ８９は、ステップＳ６０４０３で記録した全てのページ付近で参照光角度を変化させながら回折光量を取得する。 If it is determined that the adjustment recording has not been completed (“No” in step S60404), the controller 89 returns the control to the processing in step S60401. If it is determined that the adjustment recording has been completed (“Yes” in step S60404), the controller 89 acquires the amount of diffraction light of the learning hologram (step S60405). Specifically, the controller 89 acquires the amount of diffracted light while changing the reference light angles near all the pages recorded in step S60403.
　そして、コントローラ８９は、ステップＳ６０４０５において取得した回折光量の特徴を用いて、回折光量とページ間位相差とを対応づけ、回折光量が図９（ｂ）の状態すなわちφ＝１／２×πとなる状態の光記録媒体１とピックアップ１１との相対位置を決定する（ステップＳ６０５０６）。そして、コントローラ８９は、ステップＳ６０４０６で決定した位置に光記録媒体１を設定する（ステップＳ６０５０７）。以上が、位相制御学習処理（ステップＳ６０４の処理）である。これにより、参照光と信号光の成すピボット位置をデフォーカス方向にずらす（光路長に差を発生させる）ことが可能となり、ページを多重化しても読み出し時に隣接ページからのクロストーク成分を抑えることが可能となる。 The controller 89 associates the amount of diffracted light with the phase difference between pages using the feature of the amount of diffracted light acquired in step S60405, and determines the amount of diffracted light as shown in FIG. 9B, ie, φ = １ ／ × π. Then, the relative position between the optical recording medium 1 and the pickup 11 is determined (step S60506). Then, the controller 89 sets the optical recording medium 1 at the position determined in step S60406 (step S60507). The above is the phase control learning process (the process of step S604). This makes it possible to shift the pivot position formed by the reference light and the signal light in the defocus direction (to generate a difference in the optical path length), and to suppress crosstalk components from adjacent pages during reading even when multiplexing pages. Becomes possible.
　以上、第一の実施形態によれば、光記録および読み出しに関する装置のコストを減らしつつ、高速記録を実現することができる。具体的には、ホログラフィを用いた角度多重方式の記録方法において、記録密度を高めた記録を行う場合に、装置コストを大幅に増加させずに高速かつ良好な品質で記録可能となる。さらに言えば、ページ間隔を狭めた場合でも、光記録媒体１の位置制御によるページ間位相差を制御することにより、装置コストと記録速度を維持しながら、効果的にクロストークを低減することが可能であり、高密度化を実現可能である。 As described above, according to the first embodiment, high-speed recording can be realized while reducing the cost of an apparatus relating to optical recording and reading. Specifically, in the recording method of the angle multiplexing method using holography, when performing recording with increased recording density, recording can be performed at high speed and with good quality without significantly increasing the apparatus cost. Furthermore, even when the page interval is reduced, by controlling the phase difference between pages by controlling the position of the optical recording medium 1, it is possible to effectively reduce the crosstalk while maintaining the apparatus cost and the recording speed. It is possible, and high density can be realized.
　なお、隣接するページ間では位相マスクの影響や、ガルバノミラー３１９の角度変更時のミラー軸のシフトなどの影響により、位相ずれが発生する可能性があるため、これらの位相ずれを補償した上でページ間位相差φを制御しても構わない。 Note that a phase shift may occur between adjacent pages due to the influence of the phase mask or the shift of the mirror axis when the angle of the galvanometer mirror 319 is changed. The phase difference φ between pages may be controlled.
　また、位相制御学習（ステップＳ６０４の処理）は、ブックの記録を実施する毎に実施しても良いし、光記録媒体１を光記録再生装置１０に装着したときに一度実施するだけでも良く、またその調整頻度は限定されない。 Further, the phase control learning (the process of step S604) may be performed each time a book is recorded, or may be performed only once when the optical recording medium 1 is mounted on the optical recording / reproducing apparatus 10. The frequency of the adjustment is not limited.
　次に、第二の実施形態に係る記録データ処理方法と再生データ処理方法の概要について図１３を用いて説明する。第二の実施形態は、第一の実施形態に係る光記録再生装置１０と基本的に同様であり、差異のある点を中心に説明する。おおむね、第二の実施形態が第一の実施形態と異なる点は、第一の実施形態においては光記録媒体１のマウントごとに光記録媒体１の位置制御を実施するものであるのに対し、記録または再生を実施するページごとに光記録媒体１の位置制御を実施する点である。 Next, an outline of a recording data processing method and a reproduction data processing method according to the second embodiment will be described with reference to FIG. The second embodiment is basically the same as the optical recording / reproducing device 10 according to the first embodiment, and will be described focusing on the differences. Generally, the second embodiment is different from the first embodiment in that the position control of the optical recording medium 1 is performed for each mount of the optical recording medium 1 in the first embodiment, The point is that the position of the optical recording medium 1 is controlled for each page on which recording or reproduction is performed.
　図１３は、データ記録の動作フロー例を示す図である。図１３では、第一の実施形態の記録処理のステップＳ６１６に相当する第二の実施形態におけるデータ記録の動作フローを示している。 FIG. 13 is a diagram showing an example of an operation flow of data recording. FIG. 13 shows an operation flow of data recording in the second embodiment, which corresponds to step S616 of the recording processing of the first embodiment.
　第二の実施形態におけるデータ記録処理では、記録するページに参照光角度を設定し（ステップＳ６１６０１）、位相制御学習処理（ステップＳ６０４）で決定したページ毎の位置に光記録媒体１の位置を設定する（ステップＳ６１６０２）。そして、１ページのデータを記録し（ステップＳ６１６０３）、記録終了判定（ステップＳ６１６０４）を実施する。この記録終了判定は、第一の実施形態における位相制御学習処理のステップＳ６０４０４と同様であるが、異なるものであってもよい。 In the data recording process according to the second embodiment, the reference light angle is set for the page to be recorded (step S61601), and the position of the optical recording medium 1 is set at the position for each page determined in the phase control learning process (step S604). (Step S61602). Then, one page of data is recorded (step S61603), and a recording end determination (step S61604) is performed. This recording end determination is the same as step S60404 of the phase control learning process in the first embodiment, but may be different.
　記録終了判定（ステップＳ６１６０４）において記録終了と判定されなかった場合（ステップＳ６１６０４にて「Ｎｏ」の場合）には、コントローラ８９は、ステップＳ６１６０１に制御を戻す。記録終了と判定された場合（ステップＳ６１６０４にて「Ｙｅｓ」の場合）には、コントローラ８９は、ポストキュア（ステップＳ６１７）の処理に制御を進める。 If the recording end is not determined in the recording end determination (step S61604) (“No” in step S61604), the controller 89 returns the control to step S61601. If it is determined that the recording has been completed (“Yes” in step S61604), the controller 89 advances the control to post cure (step S617).
　第二の実施形態においては、データ記録だけでなく、データ再生時にも同様に、再生するページに参照光角度を設定し、ページ毎の記録した際の位置に光記録媒体１の位置を設定し、データを再生する。なお、第二の実施形態における位相制御学習処理（ステップＳ６０４に相当する処理）では、ページ毎にページ間位相差を制御可能なように光記録媒体１の位置を決定する。以上が、第二の実施形態に係る光記録再生装置である。 In the second embodiment, the reference light angle is set for the page to be reproduced, and the position of the optical recording medium 1 is set to the position at the time of recording for each page. Play the data. In the phase control learning processing (processing corresponding to step S604) in the second embodiment, the position of the optical recording medium 1 is determined so that the inter-page phase difference can be controlled for each page. The above is the optical recording / reproducing apparatus according to the second embodiment.
　このように、ページ毎に光記録媒体１の位置制御を実施し、記録および再生をすることで、第二の実施形態に係る光記録再生装置では、ページ毎に適切な位相差を設け、記録または再生品質の向上を実現することができる。 As described above, by performing position control of the optical recording medium 1 for each page and performing recording and reproduction, the optical recording / reproducing apparatus according to the second embodiment provides an appropriate phase difference for each page and performs recording and reproduction. Alternatively, the reproduction quality can be improved.
　また、上述した第二の実施形態においては、光記録媒体１の位置制御はページごとに実施しているが、これに限られず、予め定めたページ数毎（例えば、４ページ毎）に実施しても良い。 In the above-described second embodiment, the position control of the optical recording medium 1 is performed for each page. However, the present invention is not limited to this. The position control is performed for each predetermined number of pages (for example, every four pages). May be.
　次に、第三の実施形態について、図１４を用いて説明する。第三の実施形態は、クロストーク低減を目的とした光記録媒体１の位置制御によるページ間位相差制御を、ホログラフィを用いた導光板１２１０に適用した実施形態である。 Next, a third embodiment will be described with reference to FIG. The third embodiment is an embodiment in which inter-page phase difference control by position control of the optical recording medium 1 for the purpose of reducing crosstalk is applied to a light guide plate 1210 using holography.
　図１４は、第三の実施形態に係る導光板の構成例を示す図である。導光板１２１０は、入力部１２０４に入力された入射光が、出力部１２０６から出射することで、入力部１２０４から出力部１２０６へと光を導くものである。具体的には、入力部１２０４および出力部１２０６には、多重記録したホログラムが設けられる。そして、入力部１２０４から出力部１２０６へ至る導光板１２１０の内壁面には、光を反射する全反射部１２０５が設けられている。全反射部１２０５に照射された入射光は反射し、出力部１２０６に設けられたホログラムに到達する。 FIG. 14 is a diagram illustrating a configuration example of a light guide plate according to the third embodiment. The light guide plate 1210 guides light from the input unit 1204 to the output unit 1206 when the incident light input to the input unit 1204 exits from the output unit 1206. Specifically, the input unit 1204 and the output unit 1206 are provided with multiplexed holograms. On the inner wall surface of the light guide plate 1210 extending from the input unit 1204 to the output unit 1206, a total reflection unit 1205 that reflects light is provided. The incident light applied to the total reflection unit 1205 is reflected and reaches a hologram provided in the output unit 1206.
　ここで、波長の異なる入射光１２０１乃至１２０３を、ホログラムを多重記録した入力部１２０４に照射すると、入力部１２０４は導光板１２１０内を全反射する角度に入射光１２０１乃至１２０３を回折させ、入射光１２０１乃至１２０３は全反射部１２０５内を伝播し、出力部１２０６に供給され、出力光１２０７乃至１２０９となって導光板１２１０外に出力される。 Here, when the incident lights 1201 to 1203 having different wavelengths are irradiated on the input unit 1204 in which the hologram is multiplex-recorded, the input unit 1204 diffracts the incident lights 1201 to 1203 to an angle that totally reflects the inside of the light guide plate 1210, and Numerals 1201 to 1203 propagate in the total reflection unit 1205, are supplied to the output unit 1206, become output lights 1207 to 1209, and output to the outside of the light guide plate 1210.
　１枚のホログラムは、限定された角度の限定された波長の光を回折させることができる。このため、ホログラムを多重することで、回折させる光の角度と波長を広げることが可能となる。このように入力部１２０４と出力部１２０６に設けたホログラムにより、導光板１２１０に入射する光を任意の位置に任意の角度で出力することができる。 One hologram can diffract light with a limited angle and a limited wavelength. Therefore, by multiplexing the holograms, it is possible to increase the angle and wavelength of the light to be diffracted. By using the holograms provided in the input unit 1204 and the output unit 1206, light incident on the light guide plate 1210 can be output to an arbitrary position at an arbitrary angle.
　このホログラフィを用いた導光板１２１０において、入射光１２０１乃至１２０３が入力部１２０４で回折する際と、出力部１２０６で出力光１２０７乃至１２０９となって導光板１２１０外に出力される際とにおいて、隣接するホログラムからのページ間クロストークが光記録媒体１の多重記録における隣接ページと同様に、外乱となって重畳されることが課題となる。本課題は、多重記録されたホログラム同士の位相差が制御されていない場合に起こりうる。位相差が制御されていない場合には、再生光がホログラム間のクロストークによって、意図しない干渉（例えば、図９(ａ)で示した「強めあう干渉」または図９(ｃ)で示した「弱めあう干渉」）の影響を受け、これにより再生強度がばらつく。これにより、導光板を用いて表示する映像の画質が劣化する等の影響がある。 In the light guide plate 1210 using holography, when the incident lights 1201 to 1203 are diffracted by the input unit 1204, and when the output light 1206 becomes output lights 1207 to 1209 and is output to the outside of the light guide plate 1210, the light is adjacent to the light. The problem is that crosstalk between pages from a hologram to be reproduced becomes a disturbance and is superimposed as in the case of adjacent pages in multiplex recording of the optical recording medium 1. This problem can occur when the phase difference between multiplexed recorded holograms is not controlled. When the phase difference is not controlled, the reproduction light causes unintended interference due to crosstalk between the holograms (for example, the "increasing interference" shown in FIG. 9A or the "increasing interference" shown in FIG. 9C). Interference), which leads to variations in playback intensity. This has the effect of deteriorating the image quality of the image displayed using the light guide plate.
　このクロストークの発生の仕組みは、光記録媒体１のページ多重化によるクロストークと同様の原理により引き起こされる現象である。このページ間クロストークを低減するために、第三の実施形態に係る導光板１２１０においても、光記録媒体１のピックアップ１１との相対位置制御と同様の位相制御をホログラムに適用する。 The mechanism of the generation of the crosstalk is a phenomenon caused by the same principle as the crosstalk due to the page multiplexing of the optical recording medium 1. In order to reduce the inter-page crosstalk, the light guide plate 1210 according to the third embodiment also applies the same phase control as that of the relative position control of the optical recording medium 1 to the pickup 11 to the hologram.
　ホログラフィを用いた導光板１２１０を製造する装置および該装置によるホログラムの製造時の動作は、第一の実施形態および第二の実施形態に係るデータ記録動作と同様であり、光記録媒体１を導光板１２１０に変更することで、導光板１２１０を製造することができる。ただし、導光板１２１０には情報を記録しないため、信号処理回路８５を設ける必要は無い。また、回転モータ５０については、データ記録時に導光板１２１０が固定可能なような機構に変更しても構わない。 An apparatus for manufacturing the light guide plate 1210 using holography and an operation for manufacturing a hologram by the apparatus are similar to the data recording operation according to the first embodiment and the second embodiment. By changing to the light plate 1210, the light guide plate 1210 can be manufactured. However, since information is not recorded on the light guide plate 1210, there is no need to provide the signal processing circuit 85. Further, the rotation motor 50 may be changed to a mechanism that can fix the light guide plate 1210 during data recording.
　このように、第一の実施形態および第二の実施形態に係る光記録再生装置１０を用いて、装着する記録媒体の位置を制御し、ページ間位相差を制御することで、入力部１２０４に照射する入射光１２０１乃至１２０３を任意の位置に任意の角度で出力するホログラムおよび出力部１２０６を構成するホログラムを製造することができる。 As described above, by using the optical recording / reproducing device 10 according to the first embodiment and the second embodiment, by controlling the position of the recording medium to be mounted and controlling the phase difference between pages, the input unit 1204 A hologram that outputs the incident light beams 1201 to 1203 to be radiated to arbitrary positions and at an arbitrary angle and a hologram that forms the output unit 1206 can be manufactured.
　なお、本発明は上記の実施形態に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。 Note that the present invention is not limited to the above embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above.
　また、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 Also, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.
　また、上記の各構成、機能、処理部等は、それらの一部又は全部を、例えば集積回路で設計する等によりハードウェアで実現してもよい。また、上記の各構成、機能等は、プロセッサがそれぞれの機能を実現するプログラムに応じて演算を実行するソフトウェア制御によって実現してもよい。各機能を実現するプログラム、テーブル、ファイル等の情報は、メモリや、ハードディスク、ＳＳＤ（Ｓｏｌｉｄ　Ｓｔａｔｅ　Ｄｒｉｖｅ）等の記録装置、または、ＩＣ（Ｉｎｔｅｇｒａｔｅｄ　Ｃｉｒｃｕｉｔ）カード、ＳＤカード、ＤＶＤ等の記録媒体に格納しておき、実行時にＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）等に読み出され、ＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）等により実行することができる。 The above-described configurations, functions, processing units, and the like may be partially or entirely realized by hardware, for example, by designing an integrated circuit. Further, each of the above-described configurations, functions, and the like may be realized by software control in which a processor performs an operation in accordance with a program that realizes each function. Information such as programs, tables, and files for realizing each function is stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC (Integrated Circuit) card, an SD card, or a DVD. In addition, at the time of execution, it is read out to a RAM (Random Access Memory) or the like, and can be executed by a CPU (Central Processing Unit) or the like.
　また、制御線や情報線は説明上必要と考えられるものを示しており、製品上必ずしも全ての制御線や情報線を示しているとは限らない。実際には殆ど全ての構成が相互に接続されていると考えてもよい。 制 御 Also, the control lines and information lines indicate those which are considered necessary for explanation, and do not necessarily indicate all control lines and information lines on the product. In fact, it may be considered that almost all components are interconnected.
　また、上記した各構成、機能、処理部等は、それらの一部又は全部を、例えば別の装置で実行してネットワークを介して統合処理する等により分散システムで実現してもよい。 The above-described configurations, functions, processing units, and the like may be realized in a distributed system by executing a part or all of them, for example, on another device and performing integrated processing via a network.
　また、上記した実施形態の技術的要素は、単独で適用されてもよいし、プログラム部品とハードウェア部品のような複数の部分に分けられて適用されるようにしてもよい。 The technical elements of the embodiments described above may be applied independently, or may be applied to a plurality of parts such as a program component and a hardware component.
　以上、本発明について、実施形態を中心に説明した。 As described above, the present invention has been described mainly on the embodiments.
　１・・・光記録媒体、１０・・・光記録再生装置、１１・・・ピックアップ、１２・・・再生用参照光光学系、１３・・・キュア光学系、１４・・・光記録媒体回転角度検出用光学系、８１・・・アクセス制御回路、８２・・・光源駆動回路、８３・・・サーボ信号生成回路、８４・・・サーボ制御回路、８５・・・信号処理回路、８６・・・信号生成回路、８７・・・シャッタ制御回路、８８・・・光記録媒体回転モータ制御回路、８９・・・コントローラ、９０・・・入出力制御回路、９１・・・外部制御装置、１００・・・光記録媒体位置制御回路、１２１０・・・導光板。 DESCRIPTION OF SYMBOLS 1 ... Optical recording medium, 10 ... Optical recording / reproducing apparatus, 11 ... Pickup, 12 ... Reference optical system for reproduction, 13 ... Cure optical system, 14 ... Rotation of optical recording medium Angle detection optical system, 81: access control circuit, 82: light source drive circuit, 83: servo signal generation circuit, 84: servo control circuit, 85: signal processing circuit, 86 ... A signal generation circuit, 87 a shutter control circuit, 88 an optical recording medium rotating motor control circuit, 89 a controller, 90 an input / output control circuit, 91 an external control device, 100 ..Optical recording medium position control circuit, 1210... Light guide plate.

Claims (14)

  1. 　ホログラフィを利用して光記録媒体に信号光と参照光との干渉パターンをホログラムとして角度多重方式で記録する光記録装置において、
    　記録する際に前記光記録装置と前記光記録媒体の互いの位置関係を変化させることができる位置制御部を有し、
    　前記位置制御部は、前記光記録装置と前記光記録媒体の互いの位置関係を変化させることにより隣接データ間で位相差を設けて記録する、
    　ことを特徴とする光記録装置。     In an optical recording device that records an interference pattern between signal light and reference light on an optical recording medium using holography as a hologram by an angle multiplexing method,
    When recording, has a position control unit that can change the mutual positional relationship between the optical recording device and the optical recording medium,
    The position control unit records by providing a phase difference between adjacent data by changing the positional relationship between the optical recording device and the optical recording medium,
    An optical recording device, comprising:
  2. 　請求項１に記載の光記録装置であって、
    　前記光記録媒体は、情報を記録可能な媒体であり、
    　前記光記録装置は、情報を前記光記録媒体に記録可能な装置であることを特徴とする光記録装置。     The optical recording device according to claim 1,
    The optical recording medium is a medium that can record information,
    The optical recording device is a device capable of recording information on the optical recording medium.
  3. 　請求項１に記載の光記録装置であって、
    　前記光記録媒体は光を受光する入力部と、
    　光を出力する出力部と、
    　光を全反射する全反射部と、を備え、
    　前記入力部と前記出力部はホログラムを記録可能であり、
    　前記光記録装置は、前記光記録媒体の外部の光であって前記入力部で受光した光を、前記全反射部に供給するホログラムと、前記全反射部から受光した光を前記光記録媒体の外部に出力するホログラムと、を前記入力部および前記出力部にそれぞれ記録可能である、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The optical recording medium, an input unit for receiving light,
    An output unit for outputting light,
    And a total reflection section that totally reflects light,
    The input unit and the output unit can record a hologram,
    The optical recording device is a light external to the optical recording medium, the light received at the input unit, a hologram to supply to the total reflection unit, the light received from the total reflection unit of the optical recording medium A hologram to be output to the outside, and can be recorded in the input unit and the output unit, respectively.
    An optical recording device, comprising:
  4. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、
    　前記光記録媒体において少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムに参照光を照射することで得られる回折光量を特定し、
    　前記少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムの間の位相差を導出し、
    　該位相差が所定の位相差となるように前記光記録装置と前記光記録媒体の互いの位置関係を決定して、前記ホログラムを記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit,
    Identifying a diffracted light amount obtained by irradiating the reference hologram to the learning hologram multiplex-recorded at at least two different angles in the optical recording medium,
    Deriving a phase difference between the learning holograms multiplexed and recorded at at least two different angles,
    Determine the positional relationship between the optical recording device and the optical recording medium such that the phase difference is a predetermined phase difference, to record the hologram,
    An optical recording device, comprising:
  5. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、前記記録の際の前記光記録媒体に対する前記参照光の角度に応じて、前記光記録装置と前記光記録媒体の互いの位置関係を変化させる、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit, according to the angle of the reference light with respect to the optical recording medium at the time of the recording, to change the mutual positional relationship between the optical recording device and the optical recording medium,
    An optical recording device, comprising:
  6. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、
    　前記光記録媒体において少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムに参照光を照射することで得られる回折光量を特定し、
    　前記少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムの間の位相差を前記回折光量の極大値に応じて導出し、
    　該位相差が所定の位相差となるように前記光記録装置と前記光記録媒体の互いの位置関係を決定して、前記ホログラムを記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit,
    Identifying a diffracted light amount obtained by irradiating the reference hologram to the learning hologram multiplex-recorded at at least two different angles in the optical recording medium,
    Deriving a phase difference between the learning holograms multiplex-recorded at at least two different angles in accordance with the maximum value of the amount of diffracted light,
    Determine the positional relationship between the optical recording device and the optical recording medium such that the phase difference is a predetermined phase difference, to record the hologram,
    An optical recording device, comprising:
  7. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、
    　前記光記録媒体において少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムに参照光を照射することで得られる回折光量を特定し、
    　前記少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムの間の位相差を前記回折光量の半値幅に応じて導出し、
    　該位相差が所定の位相差となるように前記光記録装置と前記光記録媒体の互いの位置関係を決定して、前記ホログラムを記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit,
    Identifying a diffracted light amount obtained by irradiating the reference hologram to the learning hologram multiplex-recorded at at least two different angles in the optical recording medium,
    Deriving a phase difference between the learning holograms multiplex-recorded at least at two different angles according to the half-value width of the diffracted light amount,
    Determine the positional relationship between the optical recording device and the optical recording medium such that the phase difference is a predetermined phase difference, to record the hologram,
    An optical recording device, comprising:
  8. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、
    　前記光記録媒体において少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムに参照光を照射することで得られる回折光量を特定し、
    　前記少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムの間の位相差を前記回折光量の極大値の数に応じて導出し、
    　該位相差が所定の位相差となるように前記光記録装置と前記光記録媒体の互いの位置関係を決定して、前記ホログラムを記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit,
    Identifying a diffracted light amount obtained by irradiating the reference hologram to the learning hologram multiplex-recorded at at least two different angles in the optical recording medium,
    Deriving a phase difference between the learning holograms multiplexed and recorded at at least two different angles according to the number of local maximum values of the diffracted light amount,
    Determine the positional relationship between the optical recording device and the optical recording medium such that the phase difference is a predetermined phase difference, to record the hologram,
    An optical recording device, comprising:
  9. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、前記光記録装置と前記光記録媒体の互いの位置関係を、参照光の任意の位相からピボットまでの光路長を変化させることにより隣接データ間で位相差を設けて記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit records the positional relationship between the optical recording device and the optical recording medium by providing a phase difference between adjacent data by changing an optical path length from an arbitrary phase of the reference light to a pivot. ,
    An optical recording device, comprising:
  10. 　請求項１に記載の光記録装置であって、
    　前記位置制御部は、前記光記録装置と前記光記録媒体の互いの位置関係を、前記ホログラフィのデフォーカス位置に変化させることにより隣接データ間で位相差を設けて記録する、
    　ことを特徴とする光記録装置。     The optical recording device according to claim 1,
    The position control unit records by providing a phase difference between adjacent data by changing the positional relationship between the optical recording device and the optical recording medium to a defocus position of the holography,
    An optical recording device, comprising:
  11. 　入力された光を、入力された光の位置とは別の位置に出力する導光板であって、
    　前記導光板は光を受光する入力部と、
    　光を出力する出力部と
    　光を全反射する全反射部を備え、
    　前記入力部と前記出力部はホログラムを角度多重方式で記録可能であり、
    　互いに異なる角度で記録したホログラム間の位相差は、
    　前記記録の際の前記導光板の位置に応じて設けられていることを特徴とする導光板。     A light guide plate that outputs the input light to a position different from the position of the input light,
    The light guide plate has an input unit for receiving light,
    It has an output section that outputs light and a total reflection section that totally reflects light.
    The input unit and the output unit can record a hologram by angle multiplexing,
    The phase difference between holograms recorded at different angles is
    A light guide plate provided according to the position of the light guide plate during the recording.
  12. 　ホログラフィを利用して光記録媒体に信号光と参照光との干渉パターンをホログラムとして角度多重方式で記録する光記録方法であって、
    　記録する際に光記録装置と前記光記録媒体の互いの位置関係を変化させる位置制御ステップを行い、
    　前記位置制御ステップでは、前記光記録装置と前記光記録媒体の互いの位置関係を変化させることにより隣接データ間で位相差を設ける、
    　ことを特徴とする光記録方法。     An optical recording method for recording an interference pattern between signal light and reference light on an optical recording medium using holography as a hologram by an angle multiplex method,
    When recording, perform a position control step of changing the mutual positional relationship between the optical recording device and the optical recording medium,
    In the position control step, providing a phase difference between adjacent data by changing the positional relationship between the optical recording device and the optical recording medium,
    An optical recording method, comprising:
  13. 　請求項１２に記載の光記録方法であって、
    　前記位置制御ステップでは、
    　前記光記録媒体において少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムに参照光を照射することで得られる回折光量を特定し、
    　前記少なくとも互いに異なる２つの角度で多重記録した学習用ホログラムの間の位相差を前記回折光量に応じて導出し、
    　該位相差が所定の位相差となるように前記光記録装置と前記光記録媒体の互いの位置関係を決定する、
    　ことを特徴とする光記録方法。     The optical recording method according to claim 12, wherein
    In the position control step,
    Identifying a diffracted light amount obtained by irradiating the reference hologram to the learning hologram multiplex-recorded at at least two different angles in the optical recording medium,
    Deriving a phase difference between the learning holograms multiplex-recorded at at least two different angles according to the amount of diffracted light,
    Determine the positional relationship between the optical recording device and the optical recording medium such that the phase difference becomes a predetermined phase difference,
    An optical recording method, comprising:
  14. 　請求項１２に記載の光記録方法であって、
    　前記位置制御ステップでは、前記記録の際の前記光記録媒体に対する前記参照光の角度に応じて、前記光記録装置と前記光記録媒体の互いの位置関係を変化させるステップを含む、
    　ことを特徴とする光記録方法。     The optical recording method according to claim 12, wherein
    The position control step includes a step of changing a mutual positional relationship between the optical recording device and the optical recording medium according to an angle of the reference light with respect to the optical recording medium at the time of the recording.
    An optical recording method, comprising:
PCT/JP2018/025992 2018-07-10 2018-07-10 Optical recording device, lightguide plate, and optical recording method WO2020012551A1 (en)

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