WO2014167618A1 - 光情報再生装置および調整方法 - Google Patents
光情報再生装置および調整方法 Download PDFInfo
- Publication number
- WO2014167618A1 WO2014167618A1 PCT/JP2013/060573 JP2013060573W WO2014167618A1 WO 2014167618 A1 WO2014167618 A1 WO 2014167618A1 JP 2013060573 W JP2013060573 W JP 2013060573W WO 2014167618 A1 WO2014167618 A1 WO 2014167618A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- optical information
- light
- reference light
- movable mirror
- reproduction
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 163
- 238000000034 method Methods 0.000 title claims description 26
- 238000005259 measurement Methods 0.000 claims abstract description 23
- 238000001093 holography Methods 0.000 claims abstract description 10
- 230000008859 change Effects 0.000 claims description 17
- 238000012545 processing Methods 0.000 description 19
- 238000001514 detection method Methods 0.000 description 15
- 238000010586 diagram Methods 0.000 description 12
- 238000005516 engineering process Methods 0.000 description 7
- 238000012937 correction Methods 0.000 description 6
- 238000009826 distribution Methods 0.000 description 6
- 230000010287 polarization Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000006870 function Effects 0.000 description 4
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 239000003550 marker Substances 0.000 description 2
- 235000005811 Viola adunca Nutrition 0.000 description 1
- 240000009038 Viola odorata Species 0.000 description 1
- 235000013487 Viola odorata Nutrition 0.000 description 1
- 235000002254 Viola papilionacea Nutrition 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
Classifications
-
- 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
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
- G03H1/22—Processes or apparatus for obtaining an optical image from holograms
- G03H1/2286—Particular reconstruction light ; Beam properties
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
- G03H1/26—Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique
- G03H1/2645—Multiplexing processes, e.g. aperture, shift, or wavefront multiplexing
- G03H1/265—Angle multiplexing; Multichannel 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
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
- G11B7/08547—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements
- G11B7/08564—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements using galvanomirrors
-
- 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
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
- G11B7/0857—Arrangements for mechanically moving the whole head
-
- 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
- G11B7/1362—Mirrors
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
- G03H1/22—Processes or apparatus for obtaining an optical image from holograms
- G03H1/2286—Particular reconstruction light ; Beam properties
- G03H2001/2292—Using scanning means
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H2222/00—Light sources or light beam properties
- G03H2222/50—Geometrical property of the irradiating beam
- G03H2222/56—Conjugated beam
Definitions
- the present invention relates to an apparatus and method for reproducing information from a recording medium using holography.
- the Blu-ray Disc (TM) standard using a blue-violet semiconductor laser has made it possible to commercialize an optical disc having a recording capacity of about 50 GB even for consumer use.
- HDD Hard Disk Drive
- signal light having information of page data two-dimensionally modulated by the spatial light modulator is superimposed on the reference light inside the recording medium, and the interference fringe pattern generated at that time is superimposed in the recording medium.
- This is a technology for recording information on a recording medium by causing refractive index modulation.
- the hologram recorded in the recording medium acts like a diffraction grating to generate diffracted light.
- the diffracted light is reproduced as the same light including the recorded signal light and phase information.
- the reproduced signal light is two-dimensionally detected at high speed using a photodetector such as a CMOS or a CCD.
- a photodetector such as a CMOS or a CCD.
- the hologram recording technology enables two-dimensional information to be recorded on the optical recording medium at once by one hologram, and further to reproduce this information, and a plurality of recording mediums are present at a plurality of places. Since the page data of can be overwritten, it is possible to perform large-capacity and high-speed recording and reproduction of information.
- Patent Document 1 "Simplifying the optical system of the entire angle multiplex type hologram recording / reproducing apparatus by adopting a method of changing the angle of reference light to change the incident angle of reference light to the hologram recording material" Is noted.
- the reference beam 200 is irradiated to the hologram recording material 50 through the reference beam optical system 40 at the time of reproduction, and at this time, the phase conjugate reference beam consisting of the lens 24 and the reflection mirror 25 transmits the transmitted beam.
- the optical system makes the traveling direction of transmitted light opposite to create phase conjugate reproduction light, and irradiates the hologram recording material 50 with this to generate signal light for conjugate reproduction, and this signal light for reproduction is signal light optical
- the data is reproduced by guiding it to the image sensor 26 through the system 22 and the PBS 21.
- the phase conjugate reproduction light can be created by the phase conjugate reference light optical system having a simple configuration, and the optical system can be miniaturized. It is ".
- An object of the present invention is to make it possible to adjust a reference light optical system with high accuracy by using an optical system that performs adjustment.
- the above problem is solved, for example, by combining a condenser lens and a movable mirror in a phase conjugate system that generates phase conjugate light.
- the reference beam optical system can be adjusted with high accuracy.
- FIG. 2 is a block diagram showing an apparatus for reproducing an optical information recording medium which reproduces digital information using holography.
- the optical information reproducing device 10 is connected to an external control device 91 via an input / output control circuit 90.
- the optical information reproducing apparatus 10 transmits the reproduced information signal to the external control apparatus 91 by the input / output control circuit 90.
- the optical information reproducing apparatus 10 includes a pickup 11, a reproduction reference light optical system 12, a curing optical system 13, an optical system 14 for disc rotation angle detection, and a rotation motor 50, and the optical information recording medium 1 is a rotation motor 50. Is configured to be rotatable.
- a light wave for causing the reference light emitted from the pickup 11 to be incident on the optical information recording medium 1 is generated by the reproduction reference light optical system 12.
- a reproduction light reproduced by the reproduction reference light is detected by a photodetector in the pickup 11 described later, and a signal processing circuit 85 reproduces a signal.
- the disc rotation angle detection optical system 14 is used to detect the rotation angle of the optical information recording medium 1.
- the disk rotation angle detection optical system 14 detects a signal corresponding to the rotation angle, and the controller 89 uses the detected signal to control the disk rotation motor control circuit.
- the rotation angle of the optical information recording medium 1 can be controlled via 88.
- a predetermined light source drive current is supplied from the light source drive circuit 82 to the light source in the pickup 11 and the optical system for disc rotational angle detection 14, and each light source can emit a light beam with a predetermined light amount.
- the pickup 11 is provided with a mechanism capable of sliding the position in the radial direction of the optical information recording medium 1, and position control is performed via the access control circuit 81.
- a mechanism for detecting the amount of deviation of the reference light angle is provided in the pickup 11, the servo signal generation circuit 83 generates a signal for servo control, and the amount of deviation is corrected via the servo control circuit 84. It is necessary to provide an optical information reproducing apparatus 10 with a servo mechanism for
- the reference light measurement unit 15 is provided in the pickup 11 to measure the wavefront of the reference light, and the reference light adjustment signal detection circuit 92 performs calculation to detect the deviation of the adjustment value of the reproduction reference light optical system 12.
- the controller 89 adjusts the reproduction reference light optical system 12 via the access control circuit 81 with an adjustment value corresponding to the amount of deviation of the adjustment value.
- the pickup 11 and the optical system 14 for detecting the disc rotation angle may have a single optical system configuration for simplification.
- FIG. 1 shows the principle of reproduction in an example of the basic optical system configuration of the pickup 11 in the optical information reproducing apparatus 10.
- the light beam emitted from the light source 301 is transmitted through the collimating lens 302 and then the light amount ratio of p-polarized light and s-polarized light is desired by the optical element 304 formed of, for example, a half wavelength plate.
- the optical element 304 formed of, for example, a half wavelength plate.
- the polarization direction is controlled to become a ratio
- the transmitted light is referred to as reference light and is incident on the galvano mirror 319 via the mirror 318.
- the angle of the galvano mirror 319 can be adjusted by the actuator 320, so that the angle of incidence of the reference light incident on the optical information recording medium 1 after passing through the lens 321 and the lens 322 can be set to a desired angle.
- the incident angle of reference light it may replace with a galvano mirror and may use the element which converts the wave front of reference light.
- the Galvano mirror 319 can adjust both the Bragg direction and the pitch direction of the reference light, but of course, for simplification of control, each adjustment axis
- the actuator may be arranged on the
- the Bragg direction of the reference light may be adjusted by the galvano mirror 319
- a movable prism may be disposed upstream of the galvano mirror 319
- the pitch direction of the reference light may be adjusted by the movable prism.
- the reference light is incident on the optical information recording medium 1, and the reference light transmitted through the optical information recording medium 1 is incident on the reproduction reference light optical system 12.
- the reproduction reference light optical system 12 causes the incident light to pass through the lens 327 and the 1 ⁇ 4 wavelength plate 326, and then reflects the light by the movable mirror 324.
- the reflected light passes through the quarter wave plate 326 and the lens 327 through the same optical path as at the time of incidence.
- the light that has passed through the lens 327 is a light beam of phase conjugate that has the same angle as the reference light but has a different incident direction, and the polarization is also changed by passing through the quarter wavelength plate 326 twice.
- the phase conjugate light beam is referred to as a reproduction reference light.
- the reproduction reference light reenters the optical information recording medium 1.
- the reproduction light reproduced by the reproduction reference light propagates through the objective lens 315, the relay lens 313, and the spatial filter 314. Thereafter, the reproduction light is incident on the light detector 325, and the recorded signal can be reproduced.
- an imaging element such as a CMOS image sensor or a CCD image sensor can be used as the light detector 325, but any element may be used as long as page data can be reproduced.
- a hologram corresponding to each reference beam angle is called a page
- a set of angle multiplexed pages in the same area is called a book.
- the reproduction reference light transmitted through the optical information recording medium 1 passes through the lens 322 and the lens 321, is reflected by the galvano mirror 319 and the mirror 318, and enters the PBS 331.
- the reproduction reference light is reflected by the PBS prism 331 and is incident on the reference light measurement unit 15.
- the reference light measurement unit 15 is formed of an optical system capable of measuring the magnitude of the divergence or convergence of the reproduction reference light, and in the present embodiment, it will be described based on, for example, a knife edge method used in DVD.
- the light incident on the reference light measurement unit 15 passes through the lens 328 and the spatial filter 329 and is changed to the light intensity distribution according to the degree of divergence or convergence of the reproduction reference light.
- the photodetector 330 measures the intensity distribution of the light and outputs a signal according to the amount of the light distribution.
- the configuration of the reference light measurement unit 15 may be anything as long as the magnitude of the divergence or convergence of the reproduction reference light can be measured.
- the reference light reflected by the movable mirror 324 is located downstream of the galvano mirror 319 in the present embodiment, but by arranging the reference light downstream of the galvano mirror 319, reference light measurement is performed. There is no need to move the part 15 itself, and further downsizing and speeding up become possible.
- an actuator 323 is attached to the movable mirror 324, and adjustment of the angle and position of the movable mirror is performed before information reproduction in a method described later.
- FIG. 3 is a view showing another configuration of the pickup 11.
- the light beam emitted from the light source 501 is transmitted through the collimating lens 502 and then transmitted by the collimating lens 502, and then it is After the polarization direction is controlled so that the light amount ratio becomes a desired ratio, the light is incident on the PBS prism 505.
- the light beam transmitted through the PBS prism 505 acts as a reference beam 512 and enters the lens 515 via the mirror 514.
- the lens 515 plays a role of focusing the reference light 512 on the back focus surface of the objective lens 510, and the reference light once collected on the back focus surface of the objective lens 510 is collimated again by the objective lens 510.
- the light enters the hologram recording medium 1.
- the objective lens 510 or the optical block 521 can be driven, for example, in the direction indicated by reference numeral 520, and the objective lens 510 and the objective lens can be moved by shifting the position of the objective lens 510 or the optical block 521 along the driving direction 520. Since the relative positional relationship of the focusing points on the back focus plane 510 changes, the incident angle of the reference light incident on the hologram recording medium 1 can be set to a desired angle. Note that instead of driving the objective lens 510 or the optical block 521, the incident angle of the reference light may be set to a desired angle by driving the mirror 514 with an actuator.
- the reference light is incident on the hologram recording medium 1, and the reference light transmitted through the hologram recording medium 1 is incident on the reproduction reference light optical system 12.
- the reproduction reference light optical system 12 causes the incident light to pass through the lens 327 and the 1 ⁇ 4 wavelength plate 326, and then reflects the light by the movable mirror 324.
- the reflected light passes through the quarter wave plate 326 and the lens 327 through the same optical path as at the time of incidence.
- the light that has passed through the lens 327 is a light beam of phase conjugate that has the same angle as the reference light but has a different incident direction, and the polarization is also changed by passing through the quarter wavelength plate 326 twice.
- the phase conjugate light beam is referred to as a reproduction reference light.
- the reproduction reference light reenters the optical information recording medium 1.
- the reproduction light reproduced by the reproduction reference light propagates through the objective lens 510 and the angle filter 509. Thereafter, the reproduction light may be incident on the light detector 518 to reproduce the recorded signal.
- the reproduction reference beam transmitted through the optical information recording medium 1 passes through the lens 510 and the lens 515, is reflected by the galvano mirror 514, and enters the PBS 505.
- the reproduction reference light is reflected by the PBS prism 505 and is incident on the reference light measurement unit 15.
- the reference light measurement unit 15 is formed of an optical system capable of measuring the magnitude of the divergence or convergence of the reproduction reference light, and in the present embodiment, it will be described based on, for example, a knife edge method used in DVD.
- the light incident on the reference light measurement unit 15 passes through the lens 328 and the spatial filter 329 and is changed to the light intensity distribution according to the degree of divergence or convergence of the reproduction reference light.
- the photodetector 330 measures the intensity distribution of the light and outputs a signal according to the amount of the light distribution.
- the configuration of the reference light measurement unit 15 may be anything as long as the magnitude of the divergence or convergence of the reproduction reference light can be measured.
- an actuator 323 is attached to the movable mirror 324, and adjustment of the angle and position of the movable mirror is performed before information reproduction in a method described later.
- the optical system shown in FIG. 3 has the advantage of being able to be significantly miniaturized as compared with the optical system configuration shown in FIG. 1 by making the reproduction light and the reference beam incident on the same objective lens.
- FIG. 4 shows an operation flow of reproduction in the optical information reproducing apparatus 10.
- a flow relating to reproduction using holography in particular will be described.
- FIG. 4 (a) shows an operation flow from the insertion of the optical information recording medium 1 into the optical information reproducing apparatus 10 until the preparation for reproduction is completed
- FIG. 4 (b) is an optical information recording medium from the preparation completion state. 7 shows an operation flow until the information recorded in 1 is reproduced.
- the optical information reproducing apparatus 10 determines whether the inserted medium is a medium for recording or reproducing digital information using holography, for example. Perform (602).
- the optical information reproducing apparatus 10 reads control data provided on the optical information recording medium (603) For example, information on an optical information recording medium and information on various setting conditions at the time of reproduction, for example, are acquired.
- the operation flow from the ready state to the reproduction of the recorded information is first the seek operation (621) to control the access control circuit 81 to control the pickup 11 and the reference light for reproduction.
- the position of the optical system 12 is positioned at a predetermined position of the optical information recording medium.
- the optical information recording medium 1 When the optical information recording medium 1 has address information, it reproduces the address information, confirms whether it is positioned at the target position, and if it is not arranged at the target position, calculates the amount of deviation from the predetermined position. And repeat the action of repositioning.
- the reference light is emitted from the pickup 11, the information recorded on the optical information recording medium is read (622), and the reproduction data is transmitted (613).
- FIG. 6 shows a reproduction data processing flow in the signal processing circuit 85 until the reproduction data transmission processing 624 in the input / output control circuit 90 after the two-dimensional data are detected by the light detector 325.
- the image data detected by the light detector 325 is transferred to the signal processing circuit 85 (911).
- the image position is detected (912) based on the markers included in the image data, and distortions such as inclination, magnification, and distortion of the image are corrected (913), and then binarization processing (914) is performed to remove the markers.
- binarization processing 914 is performed to remove the markers.
- 915 one page of two-dimensional data is acquired (916).
- an error correction process (917) is performed to remove the parity data string.
- a descrambling process (918) is performed, and a CRC error detection process (919) is performed to delete a CRC parity, and then user data is transmitted (920) via the input / output control circuit 90.
- FIG. 5 is a block diagram of the signal processing circuit 85 of the optical information reproducing apparatus 10. As shown in FIG.
- the controller 89 instructs the signal processing circuit 85 to reproduce data of one page input from the pickup 11.
- the processing instruction from the controller 89 is notified to the sub controller 801 in the signal processing circuit 85 via the control line 811.
- the sub controller 801 controls each signal processing circuit via the control line 811 to operate each signal processing circuit in parallel.
- the memory control circuit 803 is controlled to store image data input from the pickup 11 via the pickup interface circuit 810 in the memory 802 via the data line 812.
- the image position detection circuit 809 performs control to detect a marker from the image data stored in the memory 802 and extract an effective data range.
- the image distortion correction circuit 808 performs distortion correction such as inclination, magnification, and distortion of the image, and controls to convert the image data into an expected two-dimensional data size.
- Each bit data of a plurality of bits making up the size converted two-dimensional data is binarized to determine “0” or “1” in the binarization circuit 807, and the data is arranged in the memory 802 by the output data of the reproduction data. Control to store.
- an error correction circuit 806 corrects an error contained in each data string
- a descrambling circuit 805 descrambles adding a pseudo random number data string
- a CRC operation circuit 804 causes an error in user data on the memory 802. Make a confirmation not included. Thereafter, the user data is transferred from the memory 802 to the input / output control circuit 90.
- the inventor describes in detail the reproduction reference light optical system 12 and the adjustment method of the movable mirror 324 in detail.
- the reproduction reference light optical system 12 is an optical system in which the lens 327 and the movable mirror 324 are combined.
- reproduction reference light generated by the reproduction reference light optical system 12 have the same angle, position, and aberration as the incident reference light.
- FIGS. 7a, 7b, and 7c are diagrams showing the optical path of the reference beam for reproduction when positioned at the ideal position of the movable mirror 324.
- FIG. FIGS. 7a, 7b and 7c show the optical paths when the incident angles of the reference light are different.
- the solid line is the reference light
- the dotted line is the reproduction reference light reflected by the mirror.
- the optical axis of the incident reference beam changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflection surface of the movable mirror 324 is positioned perpendicular to the optical axis of the incident light and at the focal point of the convergent light.
- the reflected light becomes diverging light, passes through the same optical path as the incident light, and enters the lens 327.
- the light passing through the lens becomes parallel light traveling in the same direction as the incident light in the opposite direction.
- FIG. 7b and FIG. 7c show the position where the distance and angle with the lens of the movable mirror 324 are optimum, and the reproduction reference light is emitted through the same optical path as the incident reference light. .
- FIGS. 8a, 8b and 8c are diagrams showing the optical path of the reproduction reference beam when the movable mirror 324 is far from the lens 327.
- FIG. FIGS. 8a, 8b, and 8c show the optical paths when the incident angles of the reference light are different.
- the solid line is the reference light
- the dotted line is the reproduction reference light reflected by the mirror.
- the optical axis of the incident reference light changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflection surface of the movable mirror 324 is positioned perpendicular to the optical axis of the incident light, but farther from the focal point of the convergent light. Therefore, the convergent light changes into divergent light and enters the mirror.
- the reflected light is wider than the incident light and is incident on the lens 327.
- the light having passed through the lens becomes convergent light, and is emitted from the reference light optical system 12 for reproduction.
- FIGS. 9a, 9b, and 9c are diagrams showing the optical path of the reproduction reference beam when the movable mirror 324 is close to the lens 327.
- FIG. FIGS. 9a, 9b, and 9c show the optical paths when the incident angles of the reference light are different.
- the solid line is the reference light
- the dotted line is the reproduction reference light reflected by the mirror.
- the optical axis of the incident reference light changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflection surface of the movable mirror 324 is positioned perpendicular to the optical axis of the incident light, but closer to the focal point of the convergent light. Therefore, the convergent light continues to converge after being reflected by the mirror, and then changes to divergent light.
- the reflected light is narrower than the incident light and enters the lens 327.
- the light that has passed through the lens becomes divergent light, and is emitted from the reproduction reference light optical system 12.
- FIG. 10a, 10b, and 10c are diagrams showing the optical path of the reproduction reference beam when the movable mirror 324 is inclined with respect to the lens 327.
- FIG. 10a, 10b, and 10c respectively show light paths when the incident angles of the reference light are different.
- the solid line is the reference light
- the dotted line is the reproduction reference light reflected by the mirror.
- the optical axis of the incident reference light changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflecting surface of the movable mirror 324 is not perpendicular to the optical axis of the incident light, but is located at a position farther than the focal point of the convergent light. Therefore, the convergent light is focused by the mirror before reflection and becomes divergent light.
- the optical axis of the reflected light changes according to the inclination of the movable mirror 324, and the spot size of the light when entering the lens 327 is also increased as in FIG. 8A.
- the reproduction reference light that has passed through the lens 327 becomes light that is different in angle and converges from the incident reference light.
- the optical axis of the incident reference light changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflection surface of the movable mirror 324 is not perpendicular to the optical axis of the incident light, but is positioned at the focal position of the convergent light. Therefore, the convergent light is focused at the reflection position by the mirror and the reflected light becomes divergent light.
- the optical axis of the reflected light changes according to the tilt of the movable mirror 324 and enters the lens 327.
- the reference light for reproduction which has passed through the lens 327 is different in angle from the incident reference light, it becomes light which becomes parallel light.
- the optical axis of the incident reference light changes at the lens 327.
- the reference light which is parallel light also becomes convergent light and is incident on the movable mirror 324.
- the reflection surface of the movable mirror 324 is not perpendicular to the optical axis of the incident light, but is positioned closer to the focal point of the convergent light. For this reason, the convergent light is reflected by the mirror and then focused and becomes divergent light.
- the optical axis of the reflected light changes with the inclination of the movable mirror 324, and the spot size of the light when entering the lens 327 is also increased as in FIG. 9A.
- the reproduction reference light having passed through the lens 327 becomes light which is different in angle and diverges from the incident reference light.
- the reproduction reference light generated by the position and tilt of the movable mirror 324 changes.
- Reproduction of the hologram is characterized in that a reproduction signal can be obtained only by the reference beam which is the same as that during recording or phase conjugate.
- the reproduction reference light with the position of the movable mirror 324 shifted from the ideal state causes deterioration of the reproduction performance.
- the optical information reproducing apparatus 10 needs to perform adjustment to move the movable mirror 324 to an optimal position.
- FIG. 11a and 11b are diagrams showing the output of the reference light adjustment signal detection circuit 92 when the reference light is scanned in the Bragg direction.
- FIG. 11a shows that the reference beam for reproduction changes from convergence to divergence with respect to the scanning of the reference beam in the Bragg direction. From this, it can be understood that the movable mirror 324 is inclined. Also, the direction of inclination can be known from the direction of change of divergence and convergence. If the degree of divergence or convergence of the reference beam for reproduction does not change even if the reference beam is scanned as shown in FIG. 11b by operating the actuator 323 so as to correct the tilt of the movable mirror, the tilt of the movable mirror 324 Can be corrected.
- the Bragg direction is the incident angle direction of the reference light in the direction in which multiplexing is performed when angle multiplexing is performed on the optical information recording medium 1.
- the pitch direction described later is an angle perpendicular to the Bragg direction.
- FIG. 12 is a table showing the change of the reproduction reference light due to the scanning of the reference light according to the shift direction of the movable mirror 324.
- the reproduction reference light does not change. From this, it is possible to adjust to the optimum angle of the movable mirror 324 by scanning the reference light in the angular direction to be adjusted and measuring the change of the reproduction reference light.
- the amount of deviation in the focus direction may be adjusted, for example, so that the reproduction reference light stored in the memory incorporated in the controller 89 becomes parallel.
- FIG. 13 shows a flow of positioning adjustment of the movable mirror 324.
- the reference beam is scanned in the Bragg direction.
- S1101 As described above, the deviation of the optimum angle of the movable mirror 324 is measured from the output of the reference light adjustment signal detection circuit 92 during scanning, and the angle of the movable mirror 324 in the Bragg direction is adjusted.
- S1102 Thereafter, the reference light is scanned in the pitch direction (S1103), and the angle of the movable mirror 324 in the pitch direction is adjusted as in the Bragg direction.
- the mirror position adjustment in the focus direction is performed based on the value of the reproduction reference light adjustment signal detection circuit (S1105).
- the adjustment position at this time is, for example, the reproduction reference light stored in the memory incorporated in the controller 89. Adjust the output to be parallel.
- the light output from the reproduction reference light optical system 12 is parallel light and can emit the reproduction reference light at an angle directly opposite to the incident angle, and a hologram having good reproduction performance is obtained. It will be possible to play.
- the movable mirror 324 As described above, by adjusting the movable mirror 324 based on the reference light adjustment signal detection circuit 92, it is possible to adjust the angle and the divergence or convergence of the reproduction reference light to an arbitrary value. By performing the above method, the mounting accuracy of the movable mirror 324 at the time of manufacturing the optical information reproducing apparatus 10 can be roughened.
- positional deviation of the movable mirror 324 due to thermal expansion due to temperature change or aging change can be corrected by adjustment.
- the movable mirror 324 at the time of reproduction can be adjusted to an optimal position.
- the output of the reference light adjustment signal detection circuit 92 during data reproduction is measured, and the correction processing is always performed when the amount of change becomes equal to or more than the value set in advance. It becomes possible to obtain the reproduction signal at.
- the present invention is not limited to the embodiments described above, but includes various modifications.
- the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.
- part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
- each of the configurations, functions, processing units, processing means, etc. described above may be realized by hardware, for example, by designing part or all of them with an integrated circuit. Further, each configuration, function, etc. described above may be realized by software by the processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files for realizing each function can be placed in a memory, a hard disk, a recording device such as a solid state drive (SSD), or a recording medium such as an IC card, an SD card, or a DVD.
- SSD solid state drive
- control lines and information lines indicate what is considered to be necessary for the description, and not all control lines and information lines in the product are necessarily shown. In practice, almost all configurations may be considered to be mutually connected.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Recording Or Reproduction (AREA)
- Optical Head (AREA)
- Holo Graphy (AREA)
Abstract
Description
特許文献1には「参照光の角度を変化させてホログラム記録材料への参照光の入射角度を変化させる方法を採用して角度多重方式のホログラム記録再生装置全体の光学系を簡単化すること」が記されている。これによると、「再生時に参照光光学系40を通して参照光200をホログラム記録材料50に照射し、その際、ホログラム記録材料50を透過した透過光をレンズ24と反射ミラー25から成る位相共役参照光光学系により、透過光の進行方向を反対向きにして位相共役再生光を作成し、これをホログラム記録材料50に照射して共役再生用信号光を発生させ、この再生用信号光を信号光光学系22、PBS21を通してイメージセンサ26に導くことによって、データを再生する。簡単な構成の位相共役参照光光学系により位相共役再生光を作成することができ、光学系を小形化することができる。」となっている。
前述したように参照光をホログラム記録媒体1に入射し、ホログラム記録媒体1を透過した参照光は、再生用参照光光学系12に入射する。
走査中の参照光調整信号検出回路92の出力から前記のように、可動ミラー324の最適角度のずれ量を測定し、可動ミラー324のブラッグ方向の角度を調整する。(S1102)
その後、参照光をピッチ方向に走査し(S1103)、ブラッグ方向と同様にピッチ方向の可動ミラー324角度の調整を行う。(S1104)
最後に再生用参照光調整信号検出回路の値を元に焦点方向のミラー位置調整を行う(S1105)この時の調整位置は、例えばコントローラ89に内蔵されたメモリに保存された再生用参照光が平行となる出力となるように調整する。
12・・・再生用参照光光学系、14・・・ディスク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、
88・・・ディスク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、
92・・・参照光調整信号検出回路、
301・・・光源、331・・・PBSプリズム、
320・・・アクチュエータ、
321・・・レンズ、322・・・レンズ、323・・・アクチュエータ、
327・・・レンズ、324・・・ミラー、325・・・光検出器
Claims (14)
- 光情報記録媒体に角度多重のホログラフィで記録された情報を再生する光情報再生装置であって、
参照光を生成する光源と、
前記光源が生成した参照光の前記光情報記録媒体への入射する角度を変化させる第一のアクチュエータと、
前記光情報記録媒体を透過した光の位相共役光を生成する、集光レンズと、可動ミラーとを組み合わせた位相共役生成手段と、
前記可動ミラーを駆動させる第二のアクチュエータと、
前記位相共役光の発散収束を計測する参照光計測部と、
を備えた光情報再生装置。 - 前記第二のアクチュエータは、前記参照光計測部の計測結果に応じて前記稼動ミラーを駆動させることを特徴とする請求項1に記載の光情報再生装置。
- 前記第二のアクチュエータは、前記第一のアクチュエータを駆動させたときの前記参照光計測部の計測結果が、所定値以下となるように駆動させることを特徴とする請求項1に記載の光情報再生装置。
- 前記第二のアクチュエータの駆動は、光情報記録媒体の情報再生前に行うことを特徴とする請求項2に記載の光情報再生装置。
- 前記第二のアクチュエータの駆動は、光情報記録媒体の情報再生前に行うことを特徴とする請求項3に記載の光情報再生装置。
- 前記光情報記録媒体からの情報再生中の前記参照光計測部の信号の変化を計測し、
前記信号の変化量が所定値を超えた場合に前記第二のアクチュエータの駆動を行うことを特徴とする請求項2に記載の光情報再生装置。 - 前記光情報記録媒体からの情報再生中の前記参照光計測部の信号の変化を計測し、
前記信号の変化量が所定値を超えた場合に前記第二のアクチュエータの駆動を行うことを特徴とする請求項目3に記載の光情報再生装置。 - 前記参照光計測部は、前記位相共役生成手段が生成した位相共役光を、前記第一のアクチュエータの下流で計測することを特徴とする請求項1に記載の光情報再生装置。
- 光情報記録媒体に角度多重のホログラフィで記録された情報を再生する請求項1に記載の光情報再生装置の前記可動ミラー位置を調整する調整方法であって、
位相共役光の発散収束を計測するステップと
前記計測結果により可動ミラーを駆動させるステップとを備えることを特徴とする可動ミラー調整方法。 - 第一のアクチュエータを駆動させるステップを備え、前記可動ミラーを駆動させるステップは、前記第一のアクチュエータを駆動させるステップによって前記位相共役光の発散収束を計測するステップの計測結果が所定値以下となるように前記可動ミラーを駆動させることを特徴とする請求項9に記載の可動ミラー調整方法。
- 前記調整法は、光情報記録媒体の情報再生前に行うことを特徴とする請求項9に記載の可動ミラー調整方法。
- 前記調整法は、光情報記録媒体の情報再生前に行うことを特徴とする請求項10に記載の可動ミラー調整方法。
- 前記光情報記録媒体からの情報再生中の前記参照光計測部の信号の変化を計測するステップを備え、
前記信号の変化量が所定値を超えた場合に前記ミラーの調整を行うことを特徴とする請求項9に記載の可動ミラー調整方法。 - 前記光情報記録媒体からの情報再生中の前記参照光計測部の信号の変化を計測するステップを備え、
前記信号の変化量が所定値を超えた場合に前記ミラーの調整を行うことを特徴とする請求項10に記載の可動ミラー調整方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015510965A JP6077110B2 (ja) | 2013-04-08 | 2013-04-08 | 光情報再生装置および調整方法 |
PCT/JP2013/060573 WO2014167618A1 (ja) | 2013-04-08 | 2013-04-08 | 光情報再生装置および調整方法 |
CN201380075401.7A CN105122364A (zh) | 2013-04-08 | 2013-04-08 | 光信息再现装置和调整方法 |
US14/782,919 US20160042756A1 (en) | 2013-04-08 | 2013-04-08 | Optical information playback device and adjustment method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2013/060573 WO2014167618A1 (ja) | 2013-04-08 | 2013-04-08 | 光情報再生装置および調整方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014167618A1 true WO2014167618A1 (ja) | 2014-10-16 |
Family
ID=51689055
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/060573 WO2014167618A1 (ja) | 2013-04-08 | 2013-04-08 | 光情報再生装置および調整方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US20160042756A1 (ja) |
JP (1) | JP6077110B2 (ja) |
CN (1) | CN105122364A (ja) |
WO (1) | WO2014167618A1 (ja) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109741765B (zh) * | 2017-10-27 | 2021-03-19 | 青岛泰谷光电工程技术有限公司 | 全像储存系统 |
CN111243629A (zh) * | 2020-01-21 | 2020-06-05 | 广东紫晶信息存储技术股份有限公司 | 一种反射式的全息光存储方法及装置 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007240580A (ja) * | 2006-03-06 | 2007-09-20 | Fujitsu Ltd | ホログラム記録再生装置 |
JP2011253600A (ja) * | 2010-06-04 | 2011-12-15 | Hitachi Consumer Electronics Co Ltd | 光情報記録再生装置及び光情報記録再生方法 |
JP2012138148A (ja) * | 2010-12-27 | 2012-07-19 | Hitachi Consumer Electronics Co Ltd | 情報記録再生装置および情報記録再生方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7548358B2 (en) * | 2005-05-26 | 2009-06-16 | Inphase Technologies, Inc. | Phase conjugate reconstruction of a hologram |
JP5581111B2 (ja) * | 2010-05-12 | 2014-08-27 | 日立コンシューマエレクトロニクス株式会社 | 光情報再生装置および光情報再生方法 |
WO2012032600A1 (ja) * | 2010-09-07 | 2012-03-15 | 株式会社 東芝 | 光情報記録再生装置及び光情報記録再生方法 |
JP5707147B2 (ja) * | 2011-01-24 | 2015-04-22 | 日立コンシューマエレクトロニクス株式会社 | 光情報再生方法および光情報再生装置 |
-
2013
- 2013-04-08 US US14/782,919 patent/US20160042756A1/en not_active Abandoned
- 2013-04-08 JP JP2015510965A patent/JP6077110B2/ja not_active Expired - Fee Related
- 2013-04-08 WO PCT/JP2013/060573 patent/WO2014167618A1/ja active Application Filing
- 2013-04-08 CN CN201380075401.7A patent/CN105122364A/zh active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007240580A (ja) * | 2006-03-06 | 2007-09-20 | Fujitsu Ltd | ホログラム記録再生装置 |
JP2011253600A (ja) * | 2010-06-04 | 2011-12-15 | Hitachi Consumer Electronics Co Ltd | 光情報記録再生装置及び光情報記録再生方法 |
JP2012138148A (ja) * | 2010-12-27 | 2012-07-19 | Hitachi Consumer Electronics Co Ltd | 情報記録再生装置および情報記録再生方法 |
Also Published As
Publication number | Publication date |
---|---|
CN105122364A (zh) | 2015-12-02 |
JP6077110B2 (ja) | 2017-02-08 |
US20160042756A1 (en) | 2016-02-11 |
JPWO2014167618A1 (ja) | 2017-02-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5037391B2 (ja) | 光ピックアップ、光情報記録再生装置および光学的情報記録再生方法 | |
JP5753768B2 (ja) | 光情報記録装置、光情報再生装置、光情報記録再生装置、光情報記録方法、光情報再生方法および光情報記録再生方法 | |
JP5183667B2 (ja) | 再生装置および再生方法 | |
JP5096191B2 (ja) | 光ピックアップおよび、それを用いた光情報再生装置および光情報記録再生装置 | |
JP5677272B2 (ja) | 光情報記録再生装置、光情報再生装置、光情報記録再生方法および光情報再生方法 | |
WO2014199504A1 (ja) | 光情報記録再生装置、及び調整方法 | |
JP5753767B2 (ja) | 光情報記録再生装置、光情報記録再生方法、光情報記録媒体 | |
JP6077110B2 (ja) | 光情報再生装置および調整方法 | |
JP5104695B2 (ja) | 情報記録装置 | |
JP5868494B2 (ja) | 光情報記録再生装置、および光情報記録再生方法、および再生装置 | |
JP5993956B2 (ja) | 光情報記録再生装置および光情報記録再生方法 | |
JP4551624B2 (ja) | 傾きセンサ、傾き測定装置、光ピックアップ装置及び光ディスク装置 | |
WO2014091531A1 (ja) | 光情報再生装置及び光情報再生方法 | |
JP2014203486A (ja) | 情報記録再生装置、およびそれを用いた情報記録再生方法 | |
US9728219B2 (en) | Optical information reproduction device and optical information reproduction method | |
JP2012069207A (ja) | ホログラフィを用いたホログラフィックメモリ | |
WO2014097412A1 (ja) | 光情報再生装置、及び光情報再生方法 | |
WO2013175525A1 (ja) | 光情報記録再生装置、記録条件調整方法及び光情報記録媒体 | |
JP6078634B2 (ja) | 光情報再生装置および光情報記録再生装置 | |
JP2012133879A (ja) | 情報記録装置、情報再生装置および記録媒体 | |
WO2016163312A1 (ja) | 光情報再生装置及び光情報再生方法 | |
WO2013175526A1 (ja) | 光情報再生装置及び光情報再生方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13881505 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2015510965 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14782919 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13881505 Country of ref document: EP Kind code of ref document: A1 |