JP2008027532A - Manufacturing method for master disk for reproduction of hologram recording medium, manufacturing method for reproduction hologram recording medium, manufacturing equipment for master disk for reproduction, manufacturing equipment for reproduction hologram recording medium, and master disk for reprosduction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide manufacturing equipment for a master disk for reproduction capable of manufacturing of a reproduction optical recording information medium at high speed, manufacturing equipment for a reproduction hologram recording medium and a hologram master disk for reproduction, and further, a manufacturing method for the master disk for reproduction and a manufacturing method for the reproduced hologram recording medium. <P>SOLUTION: Manufacturing equipment having an optical part 100 is used. A prism 62a is optically contacted and disposed on a surface of a master disk 60A for reproduction, and the reference light 76b for manufacturing for master disk can be lead to a recording layer 60a where a coaxial light 75b to be modulated is condensed without carrying out total reflection at a plane of incidence of the prism 62a. A spindle motor 98 and a moving pedestal 49 move a location of the recording layer 60a in which the reference light 76b for manufacturing of master disk and the coaxial light 75b to be modulated interfere, and hologram is formed. Thus a master disk for reproduction in which hologram is formed in a predetermined range is manufactured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a master for duplication of a hologram recording medium, a method for manufacturing a replica hologram recording medium, a device for manufacturing a replica master, a device for manufacturing a replica hologram recording medium, and a master for duplication.

  In recent years, holographic memory has attracted attention as a data storage device that can achieve high recording density and record and reproduce recorded data at a high transfer rate. In the holographic memory, the thickness direction of the recording medium is also used. When recording, the interference fringes between the reference light and the signal light are generated on the basis of page data corresponding to the recording data with two-dimensional information as one page unit. It is formed as a hologram inside and recorded three-dimensionally at a time. Further, at the time of reproduction, recorded data is reproduced by obtaining diffracted light generated by irradiating the hologram formed in this way with reference light (see Patent Document 1 and Non-Patent Document 1).

  On the other hand, data storage devices based on a CD (Compact Disc) format and a DVD (Digital Versatile Disc) format are now widely used. In these technologies, not only recording media that can be additionally written to and rewritten on recording media, but also ROM media (reproduction-only media) represented by CD-ROM and DVD-ROM that can be copied and distributed in large quantities. Widely used. For CD-ROMs and DVD-ROMs, a master disk that is a master disk for duplication is manufactured, or a mother disk is further manufactured from the master disk, and the master disk or the mother disk is used as a master disk, and resin is poured into the master disk. A method of manufacturing a large number of CD-ROMs and DVD-ROMs that are replicas of the master disk is employed.

  Also in the hologram recording medium, it is considered that a large amount of the hologram recording medium on which a hologram having the same shape is formed is duplicated as in the above-described CD-ROM and DVD-ROM. Such a technique is disclosed in Patent Document 2. In Patent Document 2, an optical information recording method on an optical recording information medium as a base for duplicating a large amount of a recorded hologram recording medium, and another optical recording using such an optical recording information medium as a base An optical information recording method for an information medium is disclosed. In such a technique, an important technical point is how high-speed recording can be performed on a large number of duplicate optical recording information media.

  In view of this point, Patent Document 2 generates virtual information light including information light carrying information and recording reference light as an optical information recording method on an optical information recording medium that is a source for duplication. Thus, the optical information recording medium is irradiated with virtual information light and virtual recording reference light. Also, as a method for recording optical information on a duplicate optical information recording medium, virtual information light generated from the original optical information recording medium is irradiated with optical information by irradiating the original optical information recording medium with reference light for virtual reproduction. An optical information recording method for irradiating a recording medium is described, and a technique for irradiating virtual information light onto an optical information recording medium at once using a large-diameter objective lens is disclosed.

Non-Patent Document 2 discloses a technique for replicating a replica disk by arranging a master (master disk) and a replica (replica disk) adjacent to each other and sharing the reference light for reproduction and the reference light for replica transfer. ing.
Japanese Patent Laid-Open No. 2004-226821 International Publication WO2005 / 038789A1 Pamphlet Nikkei Electronics January 17, 2005, pages 106-114 F.Mok “Holographic Read-Only Memory” in Holographic Data Storage, HJCoufal, D.Psaltis, and G.Sincerbox, eds., (Springer-Verlag, New York, 2000)

  In the optical information recording method disclosed in Patent Document 2, when recording on a large amount of duplicate optical recording information medium at high speed, it is required to increase the diameter of the objective lens according to the size of the duplicate optical recording information medium. Is done. However, it is extremely difficult to manufacture a high-resolution objective lens having a large aperture, and for this reason, an objective lens having a large diameter is expensive. For these reasons, it has been difficult to adopt such an optical information recording method. SUMMARY OF THE INVENTION The present invention solves such a problem, and an apparatus for producing a master for duplication of a hologram recording medium, which enables production of a duplicate optical recording information medium at a high speed with a cheaper production facility than shown in the background art Providing hologram recording medium manufacturing apparatus and replica hologram master, and manufacturing method of replica master recording medium and replica hologram recording medium capable of high-speed manufacturing while being simpler than shown in the background art It aims to provide a method.

  The replica master manufacturing apparatus of the present invention is a replica master manufacturing apparatus used for replicating a hologram carrying recording data onto a replica hologram recording medium. A beam splitter that divides the beam into reference light, and spatial light that modulates the coaxial light to generate modulated coaxial light in which predetermined reference light and signal light corresponding to recording data are coaxially arranged. A modulator; condensing means for condensing the modulated coaxial light on the recording layer of the master for duplication; A prism that guides the reference light for master production and is optically disposed on the surface of the master for reproduction, and the reference light for master production and the modulated coaxial light interfere with each other. Comprises a hologram forming position moving means for moving a position of the recording layer which program is formed, the.

  In this duplication master production apparatus, the beam splitter divides the light beam from the laser light source into coaxial light and master production reference light. The spatial light modulator performs spatial light modulation on the coaxial light, and generates modulated coaxial light in which predetermined reference light and signal light corresponding to recording data are coaxially arranged. The condensing means condenses the modulated coaxial light on the recording layer of the duplication master. The prism is optically arranged in close contact with the surface of the replica master, and can input the master-producing reference light to the recording layer on which the modulated coaxial light is collected. The hologram forming position moving means moves the position of the recording layer where the hologram is formed by interference between the master-producing reference light and the modulated coaxial light. In this manner, a duplication master having a hologram formed in a predetermined range can be manufactured.

  The replica hologram recording medium manufacturing apparatus of the present invention is a replica hologram recording medium manufacturing apparatus for replicating a hologram carrying recording data formed on a replica master to a replica hologram recording medium, the replica master and the replica master Positioning means having a predetermined arrangement relative to the replication hologram recording medium, and generation of reference light for replication, which generates the reference light for replication and irradiates the predetermined region of the recording layer of the master for replication with the reference light for replication Irradiating means, and a prism optically closely disposed on the surface of the replica master for guiding the reference light for replication to the recording layer of the replica master, wherein the replica master is the recording layer The reference light for duplication that has passed through is reflected again to the recording layer and has a holding substrate that transmits diffracted light from the recording layer.

  In this duplicate hologram recording medium manufacturing apparatus, the positioning means sets the relative position between the duplicate master and the duplicate hologram recording medium to a predetermined arrangement. The duplicating reference light generating and irradiating means generates duplicating reference light and irradiates a predetermined area of the recording layer of the duplicating master with the duplicating reference light. The prism is optically arranged in close contact with the surface of the duplication master in order to guide the duplication reference light to the recording layer of the duplication master. The duplication master has a holding substrate, and this holding substrate reflects the reference light for duplication that has passed through the recording layer of the duplication master again to the recording layer and transmits the diffracted light from the recording layer. . As a result, the hologram is duplicated on the duplicate hologram recording medium by the diffracted light generated from the recording layer of the duplication master.

  The duplication master of the present invention is a disc-shaped duplication master used for duplicating a hologram carrying recording data on a duplication hologram recording medium, and holds the recording layer on which the hologram is formed and the recording layer Each of the recording layers, each of which is provided with a disc-shaped holding substrate, and one of the holding substrates has a cone shape in which the thickness of the center point of the disc shape is maximized, or It is formed in a cone shape in which the thickness of the center point of the disk shape is the thinnest and functions as a prism.

  In this duplication master, the duplication master has a disk shape. A hologram for carrying recording data is formed on the recording layer. A disc-shaped holding substrate is disposed on each of both surfaces of the recording layer to hold the recording layer. One of the holding plates functions as a prism. Here, as for the shape of the prism, the thickness of the center point of the disk shape is the thickest or the thinnest.

  The method for producing a master for duplication according to the present invention is a method for producing a master for duplication used for duplicating a hologram carrying recording data on a duplication hologram recording medium, wherein a light beam from a laser light source is produced as a coaxial light and a master. A modulated reference beam and a signal beam corresponding to the recording data are coaxially arranged to generate a modulated coaxial beam, and the modulated coaxial beam The light is condensed on the recording layer of the duplication master, and the modulated coaxial light is collected without totally reflecting the reference light for master production by a prism optically closely arranged on the surface of the duplication master. To the recorded recording layer, and moves the position of the recording layer on which the hologram is formed by interference between the reference light for manufacturing the master and the modulated coaxial light, and Forming a hologram in a predetermined range of the board.

  In this method for manufacturing a master for duplication, a light beam from a laser light source is divided into a coaxial beam and a reference beam for master disc manufacture. Further, spatial light modulation is performed on the coaxial light to generate modulated coaxial light in which predetermined reference light and signal light corresponding to recording data are coaxially arranged. Further, the modulated coaxial light is condensed on the recording layer of the duplication master. Further, the reference light for master production is guided to the condensed recording layer without being totally reflected by the prism optically closely arranged on the surface of the duplication master. Further, the position of the recording layer on which the hologram is formed due to interference between the master production reference light and the modulated coaxial light is moved to form a hologram in a predetermined range of the duplication master.

  The method for producing a duplicate hologram recording medium according to the present invention is a method for producing a duplicate hologram recording medium for duplicating a hologram formed on a duplicate master carrying recording data on a duplicate hologram recording medium, the duplicate master and the duplicate master A relative position with respect to the duplicate hologram recording medium is set to a predetermined position, a prism is optically arranged in close contact with the surface of the duplicate master, and a reference light for duplication is generated to irradiate the recording layer on which the hologram of the duplicate master is formed The duplication reference light is incident on the duplication master without being totally reflected by the prism, and the diffracted light from the recording layer of the duplication master is irradiated on the duplication hologram recording medium.

  In this method of manufacturing a duplicate hologram recording medium, the relative position between the duplicate master and the duplicate hologram recording medium is set to a predetermined arrangement. In addition, a prism is optically closely arranged on the surface of the replica master. Further, duplication reference light is generated to irradiate the recording layer on which the hologram of the duplication master is formed. Further, the duplicating reference light is incident on the duplicating master without being totally reflected by the prism. Further, the diffracted light from the recording layer of the replica master is irradiated onto the replica hologram recording medium. Thereby, a duplicate hologram recording medium is manufactured.

  According to the present invention, there are provided a hologram recording medium duplicating master manufacturing apparatus, a duplicating hologram recording medium manufacturing apparatus, and a duplicating master for enabling the production of a duplicate optical recording information medium at a high speed with an inexpensive manufacturing facility. In addition, it is possible to provide a method for manufacturing a replica master and a method for manufacturing a replica hologram recording medium that can be manufactured at high speed while being inexpensive.

  Hereinafter, embodiments of the present invention will be described in order. Prior to the description of the embodiment, an example of a coaxial hologram recording / reproducing apparatus having a coaxial optical system will be briefly described. This hologram recording / reproducing apparatus is an apparatus for recording a hologram according to recording data on a hologram recording medium and reproducing the recording data from a hologram carrying the recording data of the hologram recording medium. Next, as a description of the embodiment, a replica master for manufacturing a hologram recording medium, a manufacturing method, and a replica master suitable for use therein will be described. Furthermore, a replica hologram recording medium manufacturing apparatus and a replica hologram recording medium manufacturing method using such a replica master will be described. Finally, some modifications of these embodiments will be described. Here, the contents of the term “duplicate hologram recording medium” will be described in detail below. In summary, the hologram recording medium is a hologram recording medium that duplicates a hologram carrying recording data of a master for duplication, and is a so-called ROM (Read Only). This includes both a hologram recording medium having only a function of “Memory” and a hologram recording medium having an additionally recordable area in addition to the ROM area.

(Coaxial hologram recording / reproducing device)
In the co-axial hologram recording apparatus, signal light and reference light, which will be described later, are arranged coaxially (coaxial), and by having such an arrangement, an optical path through which the signal light passes and an optical path through which the reference light passes. And at least a part of the optical components constituting each of these. With such a configuration, since the hologram recording medium including the duplicate hologram recording medium can be recorded and reproduced, the optical unit of the hologram recording apparatus (hereinafter sometimes abbreviated as recording / reproducing apparatus) can be simplified. Furthermore, since compatibility with conventional optical disks such as CDs and DVDs is relatively easy, it attracts attention as a future recording / reproducing apparatus.

  FIG. 1 shows a conceptual diagram of an optical unit 10 as a main part of a coaxial hologram recording apparatus. The optical unit 10 includes a laser light source 20, a polarization beam splitter 22, a spatial light modulator 23 formed by liquid crystal, a Fourier transform lens 24, an iris 25, a Fourier transform lens 26, a quarter wavelength plate 27, and an objective lens 28. It is provided as a major optical component. Here, the laser light source 20 includes a single mode laser, an anamorphic prism, a power monitor, an isolator, a shutter, and a spatial filter (all not shown).

  The single mode laser of the laser light source 20 is, for example, an external resonance laser and emits a single mode light beam. Then, the light beam passes through the anamorphic prism, the beam profile is shaped, the light beam intensity is measured by passing through the power monitor, and the return light to the single mode laser is blocked by passing through the isolator, and the shutter The light beam passes through the subsequent optical components depending on whether the shutter is on or off by passing through the lens, and the aberration is corrected by passing through the spatial filter to have good wavelength characteristics. Made.

  Further, the light beam passes through the following optical path constituted by the optical components shown in FIG. The light beam is reflected by the polarization beam splitter 22 and applied to the spatial light modulator 23. Then, the light beam modulated according to the pattern displayed on the spatial light modulator 23 is reflected. Here, the spatial light modulator 23 has two light beam reflection areas, ie, a signal light spatial light modulator that displays a signal light pattern based on recording data and a reference light spatial light modulator that displays a reference light pattern. ing. For example, the reference light spatial light modulator is formed as a hollow ring on the outer periphery of the spatial light modulator 23, and the signal light spatial light modulator is formed as a circle on the inner periphery of the spatial light modulator 23 in a coaxial shape. Has been. When the light beam is reflected by the spatial modulator 23, the polarization direction changes by π / 2. The light beams reflected by these reflection regions are signal light and reference light that are coaxially arranged with the same center line, and this center line is made to coincide with the optical axis of the optical component, so that the Fourier transform lens 24, It passes through the iris 25, the Fourier transform lens 26, the quarter wavelength plate 27, and the objective lens 28. That is, the signal light and the reference light are incident on the hologram recording medium 50 used for normal recording and reproduction with a common optical path.

  Here, the normal hologram recording medium 50 is a medium capable of recording and reproduction that does not have a function as a ROM, unlike a duplicate hologram recording medium manufactured by using a manufacturing apparatus and a manufacturing method of an embodiment described later. The hologram recording medium 50 includes a holding substrate 50c, a recording layer 50a, a holding substrate 50b, a reflective layer 50d, and a protective layer 50e. Each of the holding substrate 50c and the holding substrate 50b is formed of a material such as glass or polycarbonate that transmits a light beam, and the thickness (for example, 0.5 mm) of the holding substrate 50c is larger than the thickness (for example, 0.1 mm) of the holding substrate 50b. Is also considered to be large. The recording layer 50a is made of, for example, a photopolymer. The reflective layer 50d is made of, for example, aluminum, and the protective layer 50e is made of, for example, resin. Note that a duplicate hologram recording medium to be described later has recording / reproduction compatibility with the hologram recording medium 50 as described above.

  The signal light and the reference light interfere with each other in the recording layer 50a formed of a photopolymer or the like. Then, the monomer of the recording layer 50a is changed to a polymer in accordance with this interference mode, the refractive index in the minute region is changed, and recording data is recorded as a diffraction grating (hologram) corresponding to the refractive index pattern. Here, the Fourier transform lens 24 creates a Fourier image forming surface, the iris 25 shields excess light at the Fourier image forming surface, and the Fourier transform lens 26 again creates a real image forming surface. The quarter wavelength plate 27 is used for converting linearly polarized light into circularly polarized light, and the objective lens 28 is used for condensing signal light and reference light in a predetermined region of the recording layer 50a.

  Next, referring to FIG. 1 again, the optical unit 10 as a main part of the coaxial hologram reproducing apparatus will be described. In the co-axial hologram reproducing apparatus, the laser light source 20, the polarization beam splitter 22, the spatial light modulator 23, the Fourier transform lens 24, the iris 25, the Fourier transform lens 26, the quarter wavelength plate 27, and the objective lens 28 described above are used. In addition, an image sensor 29 such as a CCD (Charge Coupled Device) or a COS sensor is provided.

  In reproduction, only the reference light pattern is displayed on the reference light spatial light modulation unit of the spatial light modulator 23, and the signal light spatial light modulation unit has an all-black pattern (a pattern that prevents reflection of the light beam). As in recording, the light beam from the laser light source 20 is reflected by the polarization beam splitter 22 and reflected again by the spatial light modulator 23. Then, as described above, the spatial light modulator 23 receives the light modulation reflected only by the reference light spatial light modulation unit and reflects the Fourier transform lens 24, the iris 25, the Fourier transform lens 26, and 1/4. The light passes through the wave plate 27 and the objective lens 28 and enters the recording layer 50 a of the hologram recording medium 50.

  Here, reproduction light (diffracted light) corresponding to the hologram formed in the recording layer 50a is generated by the reference light and reflected by the reflective layer 50d. This reproduction light passes through each optical component in the order of the objective lens 28, the quarter wavelength plate 27, the Fourier transform lens 26, the iris 25, and the Fourier transform lens 24, and the polarization direction is π by the quarter wavelength plate 27. The image sensor 29 is irradiated with the reproduction light that has been changed by / 2 to become linearly polarized light and whose traveling direction of the light beam has been changed by the action of the polarization beam splitter 22. Since the electric signal obtained from the image sensor 29 is a signal corresponding to the hologram shape, that is, the recording data, the recording data can be reproduced from the electric signal in a control unit (not shown).

  Here, the coaxial hologram recording / reproducing apparatus (apparatus capable of both recording and reproduction) includes all of the above-described optical components related to the recording operation and the above-described optical components related to the reproducing operation. As an example, the optical system is configured. In addition, the coaxial hologram recording apparatus includes only the optical components related to the recording operation described above, and the coaxial hologram reproducing apparatus includes only the optical components related to the reproduction operation described above. It is.

(Production apparatus, production method, and duplication master for duplication master for duplication of hologram recording medium)
A hologram reproducing apparatus having the optical unit 10 shown in FIG. 1 makes it possible to reproduce recorded data, or to manufacture a duplicate hologram recording medium that allows additional recording (recording) and reproduction when it has an additional recordable area. 2, 3, 5, 8, and 10 show the main part of a manufacturing apparatus (hereinafter abbreviated as a duplication master production apparatus) for producing a master (hereinafter abbreviated as a duplication master). Will be described with reference to FIG. The operation of the duplication master production apparatus will be described with reference to FIGS. 4, 6, 7 and 9. FIG. 2 to 7 are diagrams for explaining a technique for manufacturing the replica master according to the first embodiment, and FIGS. 8 to 10 are diagrams for manufacturing the replica master according to the second embodiment. It is a figure for demonstrating a technique. Here, there is an unrecorded master for duplication before the hologram is formed, or a master for duplication where a hologram is partially recorded but is not formed in all planned areas (predetermined areas). The duplication master 60A is denoted by the reference numeral, the duplication master disk of the first embodiment is denoted by the duplication master disk 60B, and the duplication master disk of the second embodiment is denoted by the duplication master disk 60C. The following explanation will be given.

(About the master for duplication of the first embodiment and its manufacturing technology)
FIG. 2 is an optical diagram showing the main part of a duplication master disc manufacturing apparatus, which is a master disc for duplicating a duplicate hologram recording medium, which enables reproduction of recorded data by the hologram reproduction device having the optical section 10 shown in FIG. The part 100 is shown. FIG. 3 is a partially enlarged view of the optical unit 100 shown in FIG. A technique for manufacturing the duplication master according to the first embodiment will be described below with reference to FIGS. 2 and 3.

  The optical unit 100, which is the main part of the replica master manufacturing apparatus, includes a laser light source 30, a half-wave plate 40, a polarization beam splitter 32a, a polarization beam splitter 32b, a spatial light modulator 33a formed of liquid crystal, and a Fourier transform lens. 34, an iris 35, a Fourier transform lens 36, an objective lens 38, a dummy glass 61a, a prism 62a, an aperture 44, a mirror 45a, and a mirror 45b are provided as main optical components. In addition, the replica master manufacturing apparatus includes a spindle motor 48 and a moving pedestal 49 in order to move the replica master 60A relative to the optical unit 100 as a mechanical component. The spindle motor 48 presses the replication master 60A with the mounting member 47a and the mounting member 47b and rotates it around the spindle motor rotation shaft 48a serving as the rotation center axis. Then, the duplication master 60A is moved in the left-right direction (Y-axis direction) of the paper surface of FIG. 2 by a moving force from a drive mechanism (not shown). In FIG. 2, the left direction of the paper is the positive direction of the Y axis, the upper direction of the paper is the positive direction of the Z axis, and the direction from the front side to the back side of the paper is the positive direction of the X axis. Each of the axis and the Z-axis is used in the following description as being orthogonal to each other.

  The single mode laser of the laser light source 30 is an external resonance type laser represented by a Littrow type or a Littman type, for example, and emits a single mode light beam. The light beam sequentially passes through the following optical components (not shown) included in the laser light source 30. The light beam passes through the anamorphic prism, the beam profile is shaped, the light beam intensity is measured by passing through the power monitor, and the light returning to the single mode laser is blocked by passing through the isolator and passes through the shutter. Thus, whether or not the light beam passes through the subsequent optical components is controlled depending on whether the shutter is on or off, and the aberration is corrected by passing through the spatial filter to have a favorable wavelength characteristic. .

  Then, the light beam emitted from the laser light source 30 has its polarization plane rotated by the half-wave plate 40 and separated into the master production reference beam 76a and the coaxial beam 75a by the polarization beam splitter 32a. Here, the half-wave plate 40 is rotated to adjust the light amount ratio so that the light amount ratio between the modulated coaxial light 75b and the master production reference light 76b is 1: 1, and the position of the half-wave plate 40 is adjusted after the adjustment. Is fixed. The beam diameter of the light beam separated as the master production reference light 76a is adjusted by the aperture 44 so that the size of the master production reference light 76b in the duplication master 60A is appropriate. Then, the mirror 45a changes the optical path so that the duplication master 60A is not positioned on the optical path of the master production reference beam 76b, thereby bypassing the duplication master 60A. Furthermore, the master-producing reference beam 76b from the mirror 45a is incident on the prism 62a disposed below the duplication master 60A by the mirror 45b. In the above description, the upper and upper terms represent the positive direction of the Z axis, and the lower and lower terms represent the negative direction of the Z axis.

  On the other hand, the coaxial light 75a, which is a light beam before being subjected to spatial light modulation, is transmitted through the polarization beam splitter 32a, and further transmitted through the polarization beam splitter 32b to be applied to the spatial light modulator 33a. Then, the light beam as the modulated coaxial light 75b modulated according to the pattern displayed on the spatial light modulator 33a is reflected. By being reflected by the spatial light modulator 33a, the modulated coaxial light 75b has a polarization plane changed by π / 2 and is reflected by the polarization beam splitter 32b and guided to the subsequent optical path. On the other hand, since the coaxial light 75a transmitted through the polarizing beam splitter 32a and the reference light 76a for manufacturing the master reflected by the polarizing beam splitter 32a are different in phase by π / 2, the modulated coaxial beam is finally obtained. The directions of polarization of the light 75b and the reference light 76b for master production coincide with each other, and a good hologram is formed.

  Here, the spatial light modulator 33a has two light beam reflection areas, ie, a signal light spatial light modulator that displays a signal light pattern based on recording data and a reference light spatial light modulator that displays a reference light pattern. For example, a reference light spatial light modulator is formed as a hollow ring on the outer periphery of the spatial light modulator 33a, and a signal light spatial light modulator is coaxially formed as a circle on the inner periphery of the spatial light modulator 33a. It is formed in a shape. The light beams reflected by these reflection regions are modulated coaxial light 75b having the same center line and coaxially arranged as signal light and reference light, and the modulated coaxial light 75b passes through this center line. The light passes through a Fourier transform lens 34, an iris 35, a Fourier transform lens 36, an objective lens 38, and a dummy glass 61a for correcting aberrations so as to coincide with the optical axes of the following optical components. That is, the signal light and the reference light included in the modulated coaxial light 75b are incident on the duplication master 60A with a common optical path formed by the various optical components described above.

  Then, the modulated coaxial light 75b and the master-producing reference beam 76b emitted from the laser light source 30 which is the same light source as the modulated coaxial light 75b are the recording layer 60a ( In FIG. 3). Then, the monomer is changed to a polymer according to the interference mode, and the refractive index in the minute region of the recording layer 60a is changed, so that a diffraction grating (hologram) corresponding to the refractive index pattern is formed. Here, the Fourier transform lens 34 creates a Fourier image forming surface, the iris 35 shields excess light at the Fourier image forming surface, and the Fourier transform lens 36 again creates an actual image forming surface. Since the lens 38 condenses the signal light and the reference light on a predetermined region of the recording layer 60a, the dummy glass 61a reproduces the aberration caused by the duplicate hologram recording medium (see the duplicate hologram recording medium 80A in FIG. 13) described later. It is used in order to correct in advance at the time of manufacture of the master for use so that the hologram can be accurately replicated on the copy hologram recording medium manufactured using the master for reproduction. In this embodiment, the objective lens 38 and the dummy glass 61a function as an embodiment of the light collecting means.

  Further, in FIG. 2, the master production reference beam 76b is guided from the inner peripheral side of the duplication master 60A (the side closer to the spindle motor rotation shaft 48a), and the outer peripheral side of the duplication master 60A (the side far from the spindle motor rotation shaft 48a). 2), but the positions where the mirror 45a and the mirror 45b are arranged are different from those shown in FIG. 2, and the master production reference beam 76b is guided from the outer peripheral side of the duplication master 60A. A structure of escaping to the inner peripheral side of the master 60A for use can also be adopted. In this case, the arrangement direction of the prism 62a is also changed so that the thickness of the inner peripheral portion (distance in the Z-axis direction) is larger than the thickness of the outer peripheral portion. The relationship between the shape of the prism and the master production reference beam 76b is basically to make the master production reference beam 76b enter the duplication master 60A without being totally reflected by the action of the angle α of the prism. Therefore, the shape and the direction of arrangement of the prism 62a are determined in accordance with the incident direction of the master-producing reference beam 76b.

  The process of forming a hologram on the duplication master 60A by the modulated coaxial light 75b and the master production reference beam 76b will be described in more detail along the partial enlarged view shown in FIG. In FIG. 3, the same parts as those shown in FIG. 2 are denoted by the same reference numerals, and the description of the same reference numerals is omitted.

  The magnitude of the aberration generated by the dummy glass 61a due to the modulated coaxial light 75b is a duplicate hologram recording medium (for example, FIG. The hologram is selected so that an accurate hologram can be formed on the recording layer of the duplicate hologram recording medium by correcting in advance the influence of the aberration generated by the duplicate hologram recording medium 80A) shown in FIG. For example, the dummy glass 61a has an appropriate aberration as described above by adjusting the thickness and refractive index of the glass material. Here, when the magnitude of the aberration generated by the duplicate hologram recording medium is small, it is possible to manufacture the duplication master 60B having good duplication characteristics without providing the dummy glass 61a. Further, instead of the objective lens 38 and the dummy glass 61a, an objective lens having equivalent aberration characteristics may be used. In this case, such an objective lens with corrected aberration (for example, the objective lens 39 shown in FIG. 9) functions as an embodiment of the condensing unit. 4 eliminates the need for the dummy glass 61a in FIG.

  Here, the duplication master 60A has a recording layer 60a formed of a photopolymer or the like, and also has a holding substrate 60b and a holding substrate 60c formed of glass, polycarbonate, etc., and the holding substrate 60b and the holding substrate 60c. Thus, the recording layer 60a is sandwiched on both sides. The holding substrate 60b and the holding substrate 60c are not limited to glass and polycarbonate as long as they can hold the recording layer 60a and have a property of transmitting the modulated coaxial light 75b and the master-producing reference light 76b. .

  The operation of the prism 62a will be described in more detail. As shown in FIG. 3, the reference beam 76b for master production is incident at an angle such that it is totally reflected on the surface of the holding substrate 60b of the duplication master 60A (the surface above the holding substrate 60b shown in FIG. 3). Under such conditions that cause total reflection, guiding the master-producing reference beam 76b from the surface of the holding substrate 60c of the duplication master 60A (the surface below the holding substrate 60c shown in FIG. 3) causes the prism 62a to be guided. It is difficult when not used. In other words, the prism 62a is used to achieve the purpose of total reflection on the surface of the holding substrate 60b of the duplication master 60A without causing total reflection on the surface of the holding substrate 60c of the duplication master 60A.

  FIG. 4 shows the relationship between the incident angle and the reflectance for a P-polarized light beam (hereinafter referred to as a P-polarized wave) and an S-polarized light beam (hereinafter referred to as an S-polarized wave) (Source: Murata). Kazumi, Science Library Physics 9 “Optics” Science Co., Ltd. Published on October 25, 1979. According to FIG. 4, when the refractive index of air is 1 and the refractive index of the holding substrate 60c of the replica master 60A is 1.5, the P-polarized wave is 33.7 degrees indicated by the angle Φb. It indicates that the incident light is the best when incident, and the S-polarized wave and the P-polarized wave are totally reflected when incident at an angle of 41.8 degrees or more shown by the critical angle Φc. Yes. In normal reflection and refraction, the reflectivity varies greatly depending on the difference between the P-polarized wave and the S-polarized wave, but there is no such large difference in total reflection. For this reason, the modulated coaxial light 75b and the master-producing reference light 76b may be either P-polarized waves or S-polarized waves. Further, in the case of circularly polarized light, the recording efficiency is inferior, but it cannot be used in this method. In this case, the critical angle Φc is substantially the same 41.8 degrees.

  In the present embodiment, the master-producing reference beam 76b is totally reflected on the incident-side surface of the holding substrate 60c of the duplication master 60A while satisfying the condition of total reflection on the upper surface of the holding substrate 60b of the duplication master 60A. The condition for satisfactorily entering the duplication master 60A is realized by adjusting the refractive index and the angle α of the prism 62a. As an example of the embodiment, the refractive index of the holding substrate 60b is 1.5, the refractive index of the holding substrate 60c is 1.5, the refractive index of the prism 62a is 1.5, and the angle α is 30 degrees. However, these constants can be determined as appropriate. For example, the angle α of the prism 62a may have any of the following relationships. If the prism 62a is not provided, the refraction angle of the reference beam 76b for master production incident on the replication master 60A at an incident angle of π / 2 (parallel to the surface of the holding substrate 60c) after being incident on the holding substrate 60c is It becomes equal to the critical angle Φc, and its value is 41.8 °. When the critical angle is an angle γ and the reflection angle at the holding substrate 60b is an angle β, the angle α of the prism may be in a range where the relationship of angle α> (angle β−angle γ) is satisfied. It is. In such a relationship, the master production reference beam 76b is incident on the surface of the prism 62a and the surface of the holding substrate 60c without being reflected. In order to make the light beam incident more efficiently, it is desirable that the incident surface of the prism 62a be a non-reflective coating.

  The above is the ideal state, but even in the non-ideal state, by arranging the prism 62a, theoretically the light is totally reflected on the upper surface of the holding substrate 60b. The light beam can be effectively used by causing almost all the light amount of the master-producing reference beam 76b to enter the prism 62a while generating very slight reflection on the surface of the substrate and the surface of the holding substrate 60c.

  Further, when the surfaces of the prism 62a and the holding substrate 60c that are opposed to each other are not in close contact with each other, total reflection may occur again at the boundary between the two. It is desirable to make both surfaces close to each other with good surface processing accuracy. It is further desirable to inject oil 63 into the gap between both surfaces, and it is desirable that the refractive index of the oil 63 be close to the refractive index of the holding substrate 60c and the refractive index of the prism 62a. In this way, the master-producing reference beam 76b is refracted and incident at the incident interface of the prism 62a without being effectively totally reflected, passes through the oil 63 layer, and holds the replication master 60A holding substrate. After being incident on 60c and passing through the recording layer 60a, it is totally reflected by the holding substrate 60c. That is, the oil 63 is used to optically place the prism 62a on the holding substrate 60c that is the surface of the duplication master 60A.

  Here, the optically close arrangement refers to whether or not the holding substrate 60c and the prism 62a are in close contact from the optical viewpoint, without regard to the physical arrangement of the holding substrate 60c and the prism 62a. Since the main viewpoint is that no optical reflection occurs at the interface between the holding substrate 60c and the prism 62a, for example, the interface between the holding substrate 60c and the prism 62a has ideal flatness. As in the case where the holding substrate 60c and the prism 62a are integrally formed, or in the case where an optical contact medium such as oil is filled between the holding substrate 60c and the prism 62a. This means that irregular reflection, total reflection, etc. do not occur at this interface. Therefore, from the physical viewpoint, the holding substrate 60c and the prism 62a are separated from each other, and even if they move relatively, they may correspond to an optically close arrangement.

  The oil 63 used in the embodiment is an example of an optical contact medium that is a medium used for optically close placement. The optical contact medium is not limited to the oil 63 as long as it is a medium that transmits a light beam that can be filled in the interface between the holding substrate 60c and the prism 62a. Specifically, the optical contact medium is assumed to have fluidity, and is poured from the end face of the holding substrate 60c or the prism 62a to physically satisfy the interface between the two so as to achieve the purpose of the optical contact arrangement. Can do. Further, when the holding substrate 60c and the prism 62a move relative to each other, the medium does not flow out of the interface and disappear due to this movement, and the optical adhesion of the interface is not hindered and the movement is hindered. It is desirable to have no viscosity. Further, the desirable range of the refractive index of such an optical contact medium depends on the incident angle of the light beam and the refractive index of each forming material forming the holding substrate 60c and the prism 62a. The most ideal combination of refractive indexes is that the refractive indexes of the forming materials of the holding substrate 60c and the prism 62a are equal, and the refractive index of the optical contact medium matches this. However, even if the refractive index of the optical contact medium is equal to or close to the refractive index of one of the forming materials of the holding substrate 60c or the prism 62a, a good optical contact arrangement effect is produced. In addition, if the refractive indexes of the three forming materials of the optical contact medium, the holding substrate 60c, and the prism 62a are close to each other, the effect of the close contact arrangement can be sufficiently obtained. Examples of such an optical contact medium include oil, but are not limited to oil.

  Then, the totally reflected reference light 76b for master production and the modulated coaxial light 75b interfere in the recording layer 50a, a hologram is formed, and this hologram is recorded as a change in refractive index. After the hologram is formed, the master production reference beam 76b exits from the end surface of the prism 62a (the left surface of the prism 62a shown in FIGS. 2 and 3), and the modulated coaxial light 75b is the holding substrate of the duplication master 60A. It goes out from the surface of 60c (the lower surface shown in FIGS. 2 and 3).

  As described above, the hologram is formed on the recording layer 60a of the duplication master 60A before recording the hologram, and the duplication master 60B is manufactured. Here, after a hologram is formed in a predetermined area of the recording layer 60a of the duplication master 60A, the duplication master 60A is rotated by the spindle motor 48, and a hologram is formed in another area of the recording layer 60a. Further, when the hologram is formed in a concentric shape (concentric circle), after the hologram is formed over one rotation of the master 60A for replication, the moving base 49 for moving the entire spindle motor 48 is moved in the Y-axis direction. To form a hologram in the area of the adjacent track. In this way, it is possible to manufacture a duplication master 60B in which holograms are formed in all regions of the recording layer 60a. Further, when the hologram is formed in a spiral shape (spiral shape), the replica base 60B can be manufactured by moving the moving base 49 in the Y-axis direction while rotating the replica master 60A. That is, a hologram is formed while the duplication master 60A sandwiched between the dummy glass 61a and the prism 62a fixed to the reference base together with other optical components as a part of the optical unit 100 is moved.

  More specifically, a control unit (not shown) controls the spindle motor 48, controls the moving base 49 to be moved by a moving table actuator (not shown), and moves the objective lens 38 by an objective lens actuator (not shown). Control to move in the Z-axis direction. Here, the spindle motor 48 and the movable pedestal 49 are controlled in synchronization, and form holograms sequentially in a concentric or spiral manner as described above. On the other hand, the objective lens 38 is controlled so that the modulated coaxial light 75b is condensed at a predetermined position of the recording layer 60a by the action of the feedback loop.

  For example, the feedback loop that controls the objective lens 38 operates as follows. A small amount of return light reflected from the interface between the recording layer 60a and the holding substrate 60c is detected, and this return light is condensed by a condenser lens (not shown) and a kamaboko lens (not shown), and divided into four. The above feedback loop is configured by adopting an stigma method for obtaining a focus signal from subtraction of signals generated in a diagonal direction of a photodetector (not shown). Such a control technique is a technique normally used when manufacturing a master disk of CD-ROM or DVD-ROM shown in the background art. In this embodiment, the spindle motor 48, the moving base 49, the moving base actuator, and the control unit function as an embodiment of the hologram forming position moving means.

  In this embodiment, when the holograms to be recorded on the recording layer 60a of the duplication master 60A overlap, when reproducing the duplicate hologram recording medium produced from the duplication master 60B produced in this way. In some cases, crosstalk occurs and the S / N (signal-to-noise ratio) of the reproduced signal deteriorates. In such a case, by changing the angle of the mirror 45a or the mirror 45b so that the angle of incidence of the reference beam 76b for master recording on the prism 62a is changed in advance, the S / N of the reproduction signal from the duplicate hologram recording medium is changed. It can be good.

  FIG. 5 shows an optical unit 110 which is a main part of a manufacturing apparatus according to another embodiment of a master for duplication. The difference between the optical unit 110 and the optical unit 100 is that a dummy glass 61b is used instead of the dummy glass 61a, and a prism 62b is used instead of the prism 62a. Components having the same configuration as in the optical unit 100 and having the same function are denoted by the same reference numerals, and description thereof is omitted.

  Here, the dummy glass 61b and the prism 62b are fixed by the mounting member 47a and the mounting member 47b so as to sandwich the replication master 60A, and the dummy glass 61b and the prism 62b are combined with the replication master 60A. It is characterized in that it moves relative to the master disc reference beam 76b and the modulated coaxial beam 75b. The dummy glass 61b has a disk shape and is disposed in close contact with or close to the duplication master 60A.

  The prism 62b is disposed in close contact with the replication master 60A, and as described above, the oil 63 is applied to the boundary surface in order to prevent total reflection at the boundary surface where the prism 62b and the replication master 60A are in close contact. It is more desirable to inject it. The prism 62b rotates around the spindle motor rotation shaft 48a. FIG. 5 shows a cross-sectional view taken along a line passing through the rotation center of the prism 62b. The three-dimensional structure of the prism 62b includes a central portion. Has a cone shape with a depression.

  When such a configuration is adopted, the dummy glass 61b and the prism 62b are larger in size than the optical unit 100, but the adhesion between the dummy glass 61b and the prism 62b and the duplication master 60A is high. There is an effect that it is possible to effectively prevent total reflection from occurring at those interfaces.

  Further, in FIG. 5, a structure for guiding the master disc manufacturing reference beam 76b from the inner peripheral side of the prism 62b (side closer to the spindle motor rotating shaft 48a) and to escape to the outer peripheral side of the prism 62b (side far from the spindle motor rotating shaft 48a). However, the position where the mirror 45a and the mirror 45b are arranged is changed from that shown in FIG. 5, and the reference beam 76b for manufacturing the master is moved from the outer peripheral side of the prism (the side far from the spindle motor rotating shaft 48a). It is also possible to adopt a structure that leads to the inner peripheral side of the prism (side closer to the spindle motor rotation shaft 48a). In this case, the shape of the prism is different from that of the prism 62b, and is a cone shape in which the thickness of the central portion is thicker than the outer peripheral portion. The relationship between the shape of the prism and the master production reference beam 76b is, in short, important that the master production reference beam 76b is incident on the duplication master 60A without being totally reflected by the action of the angle α of the prism. It is. Therefore, the shape of the prism is determined in accordance with the incident direction of the master-producing reference beam 76b.

  Furthermore, by using the duplication master 60A in which the holding substrate 60c and the prism 62b of the duplication master 60A are integrally formed with the same member, and the integrally formed member is replaced with the holding substrate 60c. The use of the oil 63 described above is not necessary. That is, such a duplication master includes a recording layer on which a hologram is formed, and a recording substrate disposed on both sides of the recording layer to hold the recording layer, each having a disc-shaped holding substrate. One of the substrates has a disk-shaped central point that is thickest or is formed into a thin cone shape and functions as a prism. In order to manufacture a duplicate hologram recording medium by recording a hologram with a manufacturing apparatus having a configuration similar to that shown in FIG. If the master for duplication is used, it is not necessary to separately use a prism in the technology for producing the duplication hologram recording medium of the embodiment described later.

  With reference to FIG. 6 and FIG. 7, the form of the hologram formed in the master 60B for duplication by the manufacturing apparatus which has an optical part shown in FIG. 2, FIG. 5 is demonstrated.

  FIG. 6 shows a hologram formation region (in FIG. 6, corresponding to a plane parallel to the XY plane, which is a plane including the X axis and the Y axis in FIGS. 2 and 5) of the replica master 60B. This shows the relationship between the small circles with diagonal lines) and the reference light for manufacturing master disc 76b (indicated by arrows in FIG. 6).

  7A to 7D show the relationship between the hologram recorded at a position where the rotation angle of the duplication master 60A differs and the master production reference beam 76b. In the manufacturing apparatus having the optical unit 100 shown in FIG. 2 and the optical unit 110 shown in FIG. 5, the replica master 60A is rotated by the spindle motor 48 when forming a plurality of hologram forming regions in units of pages. Therefore, in accordance with this rotation, the master-producing reference beam 76b is equivalently rotated. That is, FIG. 7A shows the direction of incidence of the master-producing reference beam 76b immediately after forming the hologram Ha by an arrow. FIG. 7B shows an equivalent incident direction of the master production reference beam 76b on which the hologram Ha is formed after the duplication master 60A is rotated by 90 ° in the rotation direction indicated by the arrow. The incident direction of the master-producing reference beam 76b immediately after forming the hologram Hb is indicated by an arrow. FIG. 7C shows an equivalent incident direction of the master production reference beam 76b on which the hologram Ha is formed after the replication master 60A is rotated by 180 ° in the rotation direction indicated by the arrow, and forms the hologram Hb. The equivalent incident direction of the master-producing reference beam 76b is indicated by an arrow, and the incident direction of the master-producing reference beam 76b immediately after the hologram Hc is formed is indicated by an arrow. FIG. 7D shows an equivalent incident direction of the master disc manufacturing reference beam 76b formed with the hologram Ha after the duplication master 60A is rotated 270 ° in the rotation direction indicated by the arrow, and forms the hologram Hb. The equivalent incident direction of the master manufacturing reference beam 76b is indicated by an arrow, the equivalent incident direction of the master manufacturing reference beam 76b immediately after forming the hologram Hc is indicated by an arrow, and immediately after the hologram Hd is formed. The incident direction of the reference light for manufacturing master disc 76b is indicated by an arrow.

  Although not shown in FIG. 7, the incident direction of the master-producing reference beam 76b on the hologram after the replica master 60A is rotated 360 ° in the rotation direction indicated by the arrow is the same as that of the hologram Ha. That is, in a hologram formed on a straight line extending radially from the center of rotation, the equivalent incident directions of all the master-recording reference beams 76b are the same. Thus, the replica master 60B on which all holograms are formed is arranged such that the equivalent incident direction of the master-producing reference beam 76b is arranged corresponding to the radiation extending from the rotation axis of the replica master 60A. This is referred to as a duplication master according to the first embodiment. The equivalent incident direction of the master-producing reference beam 76b is an important concept when manufacturing a duplicate hologram recording medium, which will be described later.

(About the master for duplication of the second embodiment and its manufacturing technology)
FIG. 8 shows an optical unit 120 which is a main part of the duplication master production apparatus according to the second embodiment. When the optical unit 120 is used, it is possible to manufacture a duplication master having a mode different from the duplication master according to the first embodiment described above. The duplication master 60C, which is the duplication master according to the second embodiment, and the manufacturing technique thereof will be described below with reference to FIGS. Components having the same configuration as those of the optical unit 100 and the optical unit 110 and having the same function are denoted by the same reference numerals, and description thereof is omitted.

  The optical unit 120 shown in FIG. 8 differs from the optical unit 100 and the optical unit 110 in that an optical unit rotation motor 51 having a rotation angle detector 51c is added as a mechanical component constituting the optical unit 120, and the spindle. The motor 48 has a rotation angle detector 48c. Here, the optical part rotation motor fixing part 51b of the optical part rotation motor 51 is fixed to the reference base. Further, the optical member is fixed to the optical unit rotating motor rotating shaft 51a so that the entire optical unit is rotated around the optical axis of the optical member through which the modulated coaxial light 75b passes. That is, the laser light source 30, the half-wave plate 40, the polarizing beam splitter 32a, the polarizing beam splitter 32b, the spatial light modulator 33a, the Fourier transform lens 34, the iris 35, the Fourier transform lens 36, the objective lens 38, the dummy glass 61a, and the prism 62a. The aperture 44, the mirror 145a, the mirror 145b, the mirror 145c, and the mirror 145d are integrally rotated by the optical unit rotation motor 51 around the optical axis of the optical member that is the center line of the modulated coaxial light 75b. (In FIG. 8, the rotation direction is indicated by reference numeral R1). Here, the mirror 145c and the mirror 145d are disposed sufficiently apart from the spindle motor rotation shaft 48a, and the reference light 76b for manufacturing the master disc even when the optical unit rotation motor rotation shaft 51a of the optical unit rotation motor 51 rotates 360 °. This path is not obstructed by the duplication master 60A.

  Each of the mirror 145a, the mirror 145b, the mirror 145c, and the mirror 145d is provided to guide the master-producing reference beam 76b to the prism 62a. The mirror-145a temporarily makes the master-producing reference beam in the X-axis direction. By changing the traveling direction of 76b, the optical member that forms the optical path through which the modulated coaxial light 75b passes is detoured so that the path of the reference light for manufacturing the master disk 76b is not obstructed. Reference light 76b for master production is incident from below the outer periphery of the master 60A for duplication, bypassing the master 60A for duplication by 145d. For this reason, the arrangement direction of the prism 62a is different from that of the optical system shown in FIG. The mirror 145a, the mirror 145b, the mirror 145c, and the mirror 145d guide the master-producing reference beam 76b to the prism 62a without disturbing the progress of the light beam by the other optical members and the duplication master 60A as described above. However, the number is not limited to four as long as it has the same function, and any other configuration may be adopted.

  With reference to FIG. 9, the form of the hologram formed in the duplication master 60C which is the duplication master produced by the production apparatus having the optical unit 120 shown in FIG. 8 will be described.

  FIG. 9 shows the relationship between the hologram forming area and the master-producing reference beam 76b as viewed from the surface of the replica master 60A (corresponding to a plane parallel to the XY plane in FIG. 8). In the manufacturing apparatus having the optical unit shown in FIG. 8, when forming a plurality of hologram forming regions in units of pages, the replica master 60A is rotated by the spindle motor 48 (in FIG. 8, the rotation direction is indicated by reference numeral R2). ) And the optical part rotating motor rotating shaft 51a of the optical part rotating motor 51 is rotated (in FIG. 8, the rotation direction is indicated by reference numeral R1) to rotate the entire optical part 120. That is, the entire optical unit 120 is rotated once by the optical unit rotating motor 51 in synchronization with one rotation of the replica master 60A by the spindle motor 48.

  The synchronized rotation of the duplication master 60A and the optical unit 120 changes the incident direction of the master production reference beam 76b as shown in FIGS. 9A to 9D to form a hologram. Accordingly, in accordance with this rotation, the master disc manufacturing reference beam 76b is equivalently incident on the duplication master disc 60A from one direction. That is, FIG. 9A shows the incident direction of the master-producing reference beam 76b immediately after forming the hologram Ha by an arrow. FIG. 9B shows an equivalent incident direction of the master production reference beam 76b on which the hologram Ha is formed after the duplication master 60A is rotated by 90 ° in the rotation direction indicated by the arrow. The incident direction of the master-producing reference beam 76b immediately after forming the hologram Hb is indicated by an arrow. FIG. 9C shows an equivalent incident direction of the master disc manufacturing reference beam 76b formed with the hologram Ha after the replication master disc 60C is rotated 180 ° in the rotation direction indicated by the arrow, and forms the hologram Hb. The equivalent incident direction of the master-producing reference beam 76b is indicated by an arrow, and the incident direction of the master-producing reference beam 76b immediately after forming the hologram Hc is indicated by an arrow. FIG. 9D shows an equivalent incident direction of the master disc manufacturing reference beam 76b formed with the hologram Ha after the duplication master 60C is rotated 270 ° in the rotation direction indicated by the arrow, and forms the hologram Hb. The equivalent incident direction of the master-producing reference beam 76b is indicated by an arrow, the equivalent incident direction of the master-producing reference beam 76b immediately after forming the hologram Hc is indicated by an arrow, and further, immediately after the hologram Hd is formed. The direction of incidence of the reference beam 76b for manufacturing a master disc is indicated by an arrow.

  Although not shown in FIG. 9, the incident direction of the master-producing reference beam 76b on the hologram after the replica master 60A is rotated 360 ° in the rotation direction indicated by the arrow is the same as that of the hologram Ha. In other words, the equivalent incident directions of all the master-producing reference beams 76b are the same. As described above, the duplication master 60C in which the equivalent incident directions of the master production reference beam 76b are arranged in the same direction is referred to as a duplication master according to the second embodiment, and will be used hereinafter.

  The control unit 52 shown in FIG. 8 rotates the optical unit rotating motor rotating shaft 51a of the optical unit rotating motor 51 in synchronization with one rotation of the replica master 60A by the spindle motor 48. The control unit 52 performs a control for rotating the whole one turn. The control unit 52 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a D / A converter, an A / D converter, It has a power amplifier (both not shown).

  The control in the control unit 52 is performed as follows. The angle detected by the rotation angle detector 48c of the spindle motor 48 and the angle detected by the rotation angle detector 48c of the optical unit rotation motor 51 are equal to each other or have a certain angle difference. The optical part rotation motor rotating shaft 51a of the part rotation motor 51 is rotated. Thus, synchronization between the rotation of the duplication master 60A and the entire rotation of the optical unit 120 is maintained. While performing such a synchronization operation, after a hologram is formed in a predetermined area of the recording layer 60a of the duplication master 60A, the duplication master 60A is rotated by the spindle motor 48, and another predetermined area of the recording layer. A hologram is formed. When forming a concentric track, a spiral is formed in which a moving pedestal 49 for moving the entire spindle motor 48 is moved in the Y-axis direction after a hologram is formed over one rotation of the replica master 60A. When the track is formed in a shape, the moving base 49 is moved in the Y-axis direction along with the rotation of the spindle motor rotating shaft 48a. As a result, it is possible to manufacture the duplication master 60C, which is the duplication master according to the second embodiment, by recording holograms in all the areas scheduled to be recorded on the duplication master 60A.

  Here, since the entire optical unit 120 is rotated, the modulated coaxial light 75b is also rotated, and the shape of the hologram is also rotated in accordance with the rotation of the duplication master 60A. Then, the shape of the hologram formed on the duplicate hologram recording medium is also rotated by such rotation. On the other hand, the shape of a hologram recorded by a general hologram recording / reproducing apparatus using the optical unit 10 as shown in FIG. 1 does not rotate in this way. Therefore, the reproduction master 60C is manufactured by the optical unit 120, and thereby, the so-called reproduction compatibility between the manufactured replication hologram recording medium and the hologram recording medium recorded by using the optical unit 10 shown in FIG. This will cause problems.

  In order to solve such a reproduction compatibility problem and eliminate the influence of rotation of the hologram formed on the hologram recording medium, a duplicate hologram recording medium is obtained by a hologram recording / reproducing apparatus having the optical unit 10 shown in FIG. When reproducing a signal corresponding to recorded data from the image, a reproduction image by reproduction light generated in the image sensor 29 formed of a set of fine photodetectors subdivided into a two-dimensional grid is reproduced by a reproduction circuit (not shown in FIG. 1). An electric signal equivalent to the rotation returned after processing is obtained, and when the rotation does not occur, the signal corresponding to the image to be generated in the image sensor 29 is reproduced, and then the reproduction process is performed. good.

(About the master for duplication of the third embodiment and its manufacturing technology)
As described above, when processing for rotating a reproduction image by reproduction light generated in the image sensor 29 is performed in a reproduction circuit to ensure reproduction compatibility, the processing load on the hologram recording / reproduction apparatus is large. In order to ensure reproduction compatibility between the duplicate hologram recording medium and the hologram recording medium recorded by the recording / reproducing apparatus having the optical unit 10 shown in FIG. 1, it is most desirable to use the same recording format at the time of recording. . In this way, for the duplication, the equivalent incident direction of the reference light for manufacturing the master disk 76b is arranged in the same direction while having the same recording format as the hologram recording medium recorded by the recording / reproducing apparatus having the optical unit 10. A technique for manufacturing such a duplication master 60D will be described below using the master as a duplication master 60D of the third embodiment.

  The duplication master 60D can be manufactured by using the optical unit 120 shown in FIG. 8, but the control unit 52 controls the spatial light modulator 33a as follows.

  The control unit 52 refers to the signal light spatial light modulation unit that displays the signal light pattern based on the recording data displayed on the spatial light modulator 33a according to the angle detected from the rotation angle detector 48c of the spindle motor 48. Both the patterns with the reference light spatial light modulator for displaying the light pattern are rotated around the optical axis. That is, each of the signal light pattern displayed on the signal light spatial light modulation unit and the reference light pattern displayed on the reference light spatial light modulation unit in the time required for one rotation of the spindle motor 48 is 1 around the optical axis. It is intended to rotate. This processing is performed in the control unit 52 by digital arithmetic processing processed by the CPU. In this way, the reproduction compatibility problem of the duplicate hologram recording medium is solved.

  FIG. 10 shows an optical unit 130 which is a main part of still another manufacturing apparatus for manufacturing the duplication master 60D. 10, components having the same configuration as those of the optical unit 100, the optical unit 110, and the optical unit 120 and having the same function are denoted by the same reference numerals, and description thereof will be omitted. Differences between the optical unit 130 shown in FIG. 10 and the optical unit 120 shown in FIG. 8 are as follows. The entire optical unit 120 rotates in synchronization with the rotation of the spindle motor rotating shaft 48a of the spindle motor 48. On the other hand, in the optical unit 130, an optical component for generating the modulated coaxial light 75b and irradiating it to the duplication master 60A is fixed to a reference table. An optical component (an optical component within a range surrounded by a thick broken line in FIG. 10) for generating the master disc reference beam 76b and irradiating the replica master disc 60A is a spindle motor of the spindle motor 48. The rotary shaft 48a rotates in synchronization with the rotation of the rotary shaft 48a. Hereinafter, the optical unit 130 will be described with reference to FIG.

  In the optical unit 130, an optical component (hereinafter referred to as a fixed unit optical component) fixed to the reference base is a transmissive spatial light modulator 33b formed of a laser light source 30, a half-wave plate 40, liquid crystal, or the like, Fourier A conversion lens 34, an iris 35, a Fourier transform lens 36, and an objective lens 38. The mechanical parts fixed to the reference table are a fixed part 71b of the movable optical part rotating motor 71 that rotates the movable part of the optical part and a spindle motor fixing part 48b of the spindle motor 48. Each of these fixed portion optical components is fixed integrally with each other.

  In the optical unit 130, optical components that rotate around the optical axis of the modulated coaxial light 75b (hereinafter referred to as a movable unit optical component) are a polarization beam splitter 32a, a mirror 145a, an aperture 44, a mirror 145b, and a prism 62a. is there. Each of these movable part optical components is fixed integrally with each other, and is smoothly centered around the optical axis of the fixed part optical component, that is, the optical axis of the modulated coaxial light 75b, using a rotation holding mechanism having a bearing (not shown). Can be rotated. As a rotating mechanism for rotating the movable part optical component, a disk-shaped pulley 73 and pulley 74 and a movable optical part rotating motor 71 are used. The rotation shaft 71a of the movable optical unit rotation motor 71 is fixed to the rotation center of the pulley 73, and the pulley 74 and the movable unit optical component are fixed so that the rotation center of the pulley 74 coincides with the optical axis of the fixed unit optical component. ing. Here, a movable part rotation detector 77 for detecting the rotation angle of the movable part optical component is arranged on the fixed side where the fixed part optical component is arranged. The movable part rotation detector 77 detects the reflected light from the radial bar code that emits a light beam and displays the rotational angle stuck on the surface of the pulley 74, thereby detecting the rotational angle of the pulley 74, that is, the movable part optics. The rotation angle of the part is detected.

  When the optical unit 130 illustrated in FIG. 10 is employed, the number of movable unit optical components can be reduced and the fixed unit optical component is formed as compared with the case where the optical unit 120 illustrated in FIG. 8 is employed. Since the modulated coaxial light 75b guided by the optical path does not rotate, the signal light pattern and the reference light according to the rotation of the spindle motor 48 as in the optical unit 120 shown in FIG. 8 in order to obtain the replica master 60D. There is no need to rotate the pattern.

  In the optical unit 130, a control unit (not shown) acts as follows to obtain synchronization of rotation between the spindle motor 48 and the movable optical unit rotation motor 71. The control unit drives the spindle motor 48. The mounting member 47a and the mounting member 47b are pressed against each other so that the replication master 60A and the dummy glass 61b rotate together with the spindle motor rotating shaft 48a. Then, a signal from the rotation angle detector 48c of the spindle motor 48 is captured. Then, the control unit compares the angle detected from the rotation angle detector 48c with the angle detected from the movable unit rotation detector 77, and this angle matches or the angle difference between them becomes a constant value. Thus, the movable optical part rotation motor 71 is controlled. Since such control processing is performed sequentially, the angle between the fixed part optical component and the movable part optical component and the rotation angle of the spindle motor rotating shaft 48a can be synchronized. Thus, as shown in FIG. 9, recording of a hologram is formed in which the equivalent incident directions of the master-producing reference beam 76b are arranged in the same direction, and the modulated coaxial beam 75b is equivalently arranged radially. A hologram duplication master 60D having an aspect can be manufactured.

(About post-processing)
The hologram duplication master 60B of the first embodiment, the hologram duplication master 60C of the second embodiment, and the hologram of the third embodiment in which the hologram is recorded as described above on the recording layer in the planned range. Each of the duplication masters 60D is used as a duplication master. When there is an unrecorded area of a hologram in the recording layer 60a of these duplication masters, the duplication master 60D is irradiated in the process of manufacturing a duplicate hologram recording medium described later. Further, the hologram may be formed on the hologram duplication master 60B, the hologram duplication master 60C, and the hologram duplication master 60D by the action of the light beam. The occurrence of such a situation means that the content recorded on the duplicate hologram recording medium at the initial stage of manufacture is different from the content recorded on the duplicate hologram recording medium at a stage after the start of production. Is not preferable.

  From this point of view, it is desirable to perform post-processing by irradiating the hologram duplication master 60B or the hologram duplication master 60D in which holograms are recorded on the recording layer 60a in a predetermined range with light having poor coherence. . This is a process of changing all the monomers remaining on the hologram duplication master 60B or the hologram duplication master 60D into polymers. The light to be irradiated is light having a wavelength at which the medium is exposed, and any light having poor coherence that does not emit diffracted light from the recorded hologram may be used. As a specific example, for example, scattered light may be collectively irradiated onto the hologram duplication master 60B or the hologram duplication master 60D.

(Manufacturing technology of duplicate hologram recording media using a master for duplication)
Various techniques can be considered as the above-described replica hologram recording medium manufacturing technique using the replica master, that is, the replica hologram recording medium manufacturing apparatus and the replica hologram recording medium manufacturing method. Indicates. In the following description, an unrecorded hologram recording medium before the hologram is recorded and a hologram recording medium in the process of manufacturing (holograms are recorded only in a part of all the areas scheduled to be recorded) The hologram recording medium at the stage) is given the reference number of the duplicate hologram recording medium 80A and used in the following description, and is manufactured using various manufacturing apparatuses described later (holograms are recorded in the entire area scheduled for recording). The hologram recording medium) is given the reference numerals of the duplicate hologram recording medium 80B to 80E and used in the following description. In any of the techniques, the duplication master is characterized by having a holding substrate that reflects the duplication reference light transmitted through the recording layer to the recording layer again and transmits the diffracted light from the recording layer. Then, the replica hologram recording medium manufacturing apparatus generates positioning reference means for arranging the relative position of the replica master and the replica hologram recording medium in a predetermined manner, the reference light for replication, and the recording layer of the replica master A reference light generating and irradiating means for irradiating a predetermined reference area with a reference light for duplication, and a prism optically arranged in close contact with the surface of the master for duplication to guide the reference light for duplication to the recording layer of the master for duplication; , Are provided. Specific embodiments will be described below.

(Regarding the production technique of the first embodiment for producing a duplicate hologram recording medium from the duplicate master 60B)
As a technique for manufacturing a duplicate hologram recording medium using the replica master 60B, a manufacturing apparatus according to the first embodiment and a manufacturing method according to the first embodiment using the manufacturing apparatus will be described. This manufacturing apparatus and manufacturing method perform replication by irradiating a duplication master 60B with a light spot and scanning the light spot in a two-dimensional direction. The duplicate hologram recording medium manufacturing apparatus 140 according to the first embodiment will be described with reference to FIG. As described above, in the duplication master 60B of the first embodiment, as shown in FIG. 7, the center of the duplication master 60B (corresponding to the rotation center of the spindle motor rotation shaft 98a shown in FIG. 11) is used as a reference. The hologram is formed by irradiating the master disc reference beam 76b radially, and this direction does not depend on the position of the replica master disc 60B in the radial direction and is the same at any position on the inner and outer circumferences. Considering this point, the duplicate hologram recording medium 80B in which the information on the duplication master 60B is duplicated is manufactured by the duplicate hologram recording medium manufacturing apparatus 140 of the first embodiment.

  The duplicate hologram recording medium manufacturing apparatus 140 according to the first embodiment includes a laser light source 90, a mirror 91a, a prism 62c, a spindle motor 98, and a duplication master 60B as main components. The laser light source 90 emits a duplicating reference beam 85a. The duplication reference beam 85a has a wavelength substantially equal to the wavelength of the master disc production reference beam 76b emitted from the laser light source 30 used when producing the duplication master disc 60B. The prism 62c has the same structure as the prism 62a shown in FIG. The prism 62c and the mirror 91a are driven by an actuator (not shown) so as to move in the direction indicated by the arrow in FIG. 11 (the positive direction of the Y axis) while maintaining a fixed positional relationship. The spindle motor 98 has a mounting member 97a and a mounting member 97b that rotate together with the spindle motor rotating shaft 98a. The mounting member 97 a and the mounting member 97 b are used to press the duplicate hologram recording medium 80 </ b> A and the duplication master 60 </ b> B so that both can be rotated by the rotational force of the spindle motor 98. In this embodiment, the mounting member 97a and the mounting member 97b function as an embodiment of the positioning means. In FIG. 12, the mirror 91a functions as an embodiment of a light beam moving means for changing the position of the spot-shaped duplication reference light irradiated to the duplication master 60B in the radial direction of the duplication master 60B. However, as another example of the light beam moving means, the laser light source 90 is moved by directly irradiating the duplication master 60B with the light beam from the laser light source 90 without using the mirror 91a. Furthermore, the laser light source 90 and the mirror 91a may be fixed, and the replica master 60B, the replica hologram recording medium 80A, the prism 62c, and the spindle motor 98 may be stacked and moved on a moving table.

  FIG. 12 shows the movement of the duplicating reference beam 85a formed as a light spot by a perspective view seen from above the duplicating hologram recording medium 80A. Here, the duplication reference beam 85a is irradiated from the same incident direction as the master disc reference beam 76b used as shown in FIG. 7 when the duplication master disc 60B of the first embodiment is produced. That is, with reference to the center of the master for duplication 60B (in FIG. 11, the center of rotation of the spindle motor rotating shaft 98a), the duplicating reference beam 85a is moved and irradiated radially, and holograms are sequentially formed to produce the replica hologram. The recording medium 80B is finally manufactured.

  More specifically, duplication is performed according to the following procedure. The rotation of the spindle motor rotation shaft 98a that rotates both the duplication master 60B and the duplication hologram recording medium 80A is stopped. The duplication reference beam 85a having a substantially circular shape on the cut surface perpendicular to the traveling direction of the light beam moves from the inner circumference of the duplication master 60B to the outer circumference in accordance with the movement of the mirror 91a. The spindle motor rotating shaft 98a stops again after rotating the replica master 60B and the replica hologram recording medium 80A (the direction of rotation is indicated by an arrow with reference numeral R2 in FIG. 2). The rotation angle is such that the movement distance on the outermost periphery of the duplication master 60B is within the length of the radius of the cross section of the duplication reference beam 85a. Again, the duplication reference beam 85a moves from the inner circumference to the outer circumference direction of the duplication master 60B according to the movement of the mirror 91a. By repeating the above procedure, it is possible to finally obtain a duplicate hologram recording medium 80B in which the holograms of all the regions scheduled to be duplicated of the duplication master 60B are duplicated.

  Another procedure is to continuously rotate the spindle motor rotating shaft 98a for rotating both the replication master 60B and the replication hologram recording medium 80A, and irradiate the replication reference light 85a for one round (360 °). The rotation of the spindle motor rotating shaft 98a is stopped. The mirror 91a is moved by a distance within the length of the radius of the cross section of the duplication reference beam 85a from the inner circumference to the outer circumference of the duplication master 60B. Again, the spindle motor rotating shaft 98a that rotates both the replica master 60B and the replica hologram recording medium 80A is continuously rotated to irradiate the reference light 85a for one round (360 °). By repeating the above procedure, it is possible to finally obtain a duplicate hologram recording medium 80B in which the holograms of all the regions scheduled to be duplicated of the duplication master 60B are duplicated.

  Further, in another procedure, the spindle motor rotating shaft 98a that rotates both the replica master 60B and the replica hologram recording medium 80A is continuously rotated, and the mirror 91a is moved from the inner periphery to the outer periphery. At this time, the spindle motor rotating shaft 98a and the mirror 91a are moved at such a moving speed that the duplication reference beam 85a can be irradiated to the entire area where duplication of the duplication master 60B is scheduled. In this way, it is possible to finally obtain a duplicate hologram recording medium 80B obtained by duplicating holograms in the entire area where duplication of the duplication master 60B is scheduled.

  In any of the above-described procedures, the replication reference beam 85a is moved in the Y-axis direction (the arrow Y in FIG. 12 indicates the movement direction), and the mirror 91a is used for replication in the rotation angle direction. The movement of the reference light 85a (the movement direction is indicated by adding the symbol R2 to the arrow in FIG. 12) irradiates all the regions to be duplicated with the reference light 85a for duplication using the spindle motor 98. In this embodiment, the laser light source 90 has a function of generating the duplication reference light 85a, and the spindle motor 98, the mirror 91a, and the actuator that moves the mirror 91a are moved to a predetermined area of the duplication master 60B. These are all configured as part of the duplicating reference light generating means.

  FIG. 13 is a partially enlarged view of FIG. 11 showing the vicinity where the duplicating reference beam 85a is incident. The holding substrate 60c of the replication master 60B and the surface of the prism 62c facing each other are in close contact with each other, and the replication reference light 85a is not totally reflected at the boundary between both surfaces. In addition, by injecting oil 63 for preventing total reflection between both surfaces, it is possible to optically closely arrange and further effectively prevent total reflection.

  In this way, the duplicating reference beam 85a incident on the holding substrate 60c is transmitted through the recording layer 60a on which the hologram is recorded and totally reflected by the holding substrate 60b. Then, when the duplicating reference beam 85a passes through the recording layer 60a, diffracted light 86 corresponding to the shape of the hologram already formed on the recording layer 60a is generated, and the diffracted light 86 records on the duplicate hologram recording medium 80A. A hologram is formed on the layer 80a. The diffracted light 86 shown by the solid line in FIG. 13 schematically shows only the diffracted light 86 from one hologram forming region, but from all of the recording portions of the recording layer 60a irradiated with the replication reference light 85a. Diffracted light is generated. This diffracted light corresponds to both signal light and reference light in the coaxial system. In this way, the diffracted light 86 reaches the duplicate hologram recording medium 80A. On the other hand, the duplication reference beam 85a is totally reflected at the interface of the holding substrate 60b and does not reach the duplication hologram recording medium 80A.

  The holding substrate 80c of the unrecorded duplicate hologram recording medium 80A is disposed in close proximity or close to the holding substrate 60b of the duplication master 60B. Here, the duplicate hologram recording medium 80A has a structure in which the recording layer 80a is held by the holding substrate 80c and the holding substrate 80b described above. The recording layer 80a is a layer formed of, for example, a photopolymer, and each of the holding substrate 80c and the holding substrate 80b is made of a material that transmits a light beam, such as glass or polycarbonate, and will be described later. The diffracted light 86 is transmitted. Since it has such a structure, a hologram is formed in the recording layer 80 a by the diffracted light including the diffracted light 86.

  Here, the diffracted light generated when the replication reference light 85a passes through the recording layer 60a is generated when the replication reference light 85a goes (when entering from the holding substrate 60c side) and when the replication reference light 85a is transmitted. It can occur both on the return after reflecting off the upper surface of the holding substrate 60b. If the hologram is formed on the recording layer 80a of the duplicate hologram recording medium 80A only by the diffracted light generated by the duplicate reference light 85a, the wavelength of the duplicate reference light 85a and the wavelength of the master production reference light 76b It is good to make the slightly different. When the duplicating reference beam 85a goes, diffracted light is generated by the action of a so-called reflection hologram, so that the wavelength dependence of the diffraction efficiency is steep, and the wavelength of the duplicating reference beam 85a and the reference light for master production A slight deviation from the wavelength of 76b reduces the generation of diffracted light, and a hologram is mainly formed in the recording layer 80a by the diffracted light generated when the duplicating reference light 85a is returned. The hologram formed in the recording layer 80a by such one diffracted light does not degenerate two diffracted lights, that is, the diffracted light by the reflection hologram and the diffracted light by the transmission hologram. For this reason, the manufacturing temperature is strictly controlled by adopting such a replication method in which the wavelength of the reference light 85a for replication and the wavelength of the reference light 76b for master production are slightly different. Even if it does not have, it has the effect that the replication hologram recording medium which has favorable S / N (signal-to-noise ratio) can be manufactured.

  If the replication hologram recording medium manufacturing apparatus 140 of the first embodiment is used, the replication reference light 85a can be introduced into the replication master 60B, and thus a hologram can be formed on the recording layer 80a of the replication hologram recording medium 80A. Easy to do. Since the duplication reference beam 85a is effectively introduced without being reflected by the surface of the holding substrate 60c on the incident side of the duplication master 60B by the action of the prism 62c, the rotation speed of the duplication master 60B is increased. However, the intensity of the light beam emitted from the laser light source 90 can be small. As a result, the speed of duplication of the duplicate hologram recording medium 80B can be improved by increasing the rotation speed of the duplication master 60B without using an expensive objective lens having a large diameter as employed in the background art. Here, in the duplicate hologram recording medium manufacturing apparatus 140, since the prism 62c is moved in conjunction with the mirror 91a, the size of the prism 62c can be reduced and the cost of the apparatus can be reduced.

  Although not shown, when the size of the prism 62c is increased to have a cone shape with a depressed center covering the entire surface of the duplicate hologram recording medium 80B, it is not necessary to move the prism in conjunction with the mirror 91a. it can.

(Regarding the production technique of the second embodiment for producing a duplicate hologram recording medium from the duplicate master 60B)
As a technique for manufacturing a duplicate hologram recording medium using the replica master 60B, a manufacturing apparatus according to the second embodiment and a manufacturing method according to the second embodiment using the manufacturing apparatus will be described. In this manufacturing apparatus and manufacturing method, replication is performed by irradiating a replication master 60B with a band of light and scanning the band of light in a one-dimensional direction. In this case, scanning in the one-dimensional direction is performed by rotating the duplication master 60B. The duplicate hologram recording medium manufacturing apparatus 150 of the second embodiment will be described with reference to FIG.

  The duplicate hologram recording medium manufacturing apparatus 150 of the second embodiment shown in FIG. 14 includes a laser light source 90, an anamorphic prism 92a, an anamorphic prism 92b, a mirror 91b, a spindle motor 98, a prism 62d, and a duplication master 60B as main components. Is. The laser light source 90, the anamorphic prism 92a, the anamorphic prism 92b, the mirror 91b, the fixed portion of the spindle motor 98, and the prism 62d are all fixed to the reference base. The duplicating reference beam 85b shaped in a band shape can be obtained by shaping the light beam from the laser light source 90 by the anamorphic prism 92a and the anamorphic prism 92b. Here, the two anamorphic prisms, the anamorphic prism 92a and the anamorphic prism 92b, are used because the length in the longitudinal direction of the belt-shaped duplication reference beam 85a is substantially equal to the radius of the duplication master 60B. This is because it is not necessary to scan the duplication reference beam 85a in the direction of the radiation extending from the center of the duplication master 60B. Therefore, when the length of the duplicating reference beam 85a in the longitudinal direction can be made sufficiently long only by the anamorphic prism 92a, the anamorphic prism 92b is not required.

  Here, the duplication master 60B and the prism 62d are moved relative to each other by the rotation of the duplication master 60B, and the prism 62d has a wedge shape and extends in a direction extending from the front surface to the back surface of the paper. The thickness (length in the vertical direction of the paper surface) is the same, and the width extending from the front surface of the paper surface to the back surface direction is not less than the length of the duplication reference light 85a in the short direction and is relatively narrow. . Although not shown, it is more desirable to fill the interface between the replica master 60B and the prism 62d with the oil 63 to achieve an optical close arrangement. The wavelength of the duplicating reference beam 85a is substantially equal to the wavelength of the master-producing reference beam 76b.

  Although not shown, the prism 62d may have a structure covering the entire surface of the duplication master 60B. In this case, the prism 62d has the same structure as the prism 62b shown in FIG. It shall have the shape of. In this case, the duplicate hologram recording medium 80A, the duplication master 60B, and the prism 62b (not shown in FIG. 14, FIG. 5 are shown) sandwiched between the mounting member 97a and the mounting member 97b and positioned. Each of the reference) can be rotated together with the spindle motor rotating shaft 98a of the spindle motor 98. In this case, the optical closeness of the opposing surfaces of the replica master 60B and the prism 62b is better than when the replica master 60B and the prism 62b move relatively. can do. Further, when a duplication master (not shown) in which the holding substrate 60c and the prism 62b are integrated is used, the optical closeness can be best.

  FIG. 15 shows a relationship between the duplicate hologram recording medium 80A and the duplication reference light 85b formed as a band of light by a perspective view seen from the upper side of the duplicate hologram recording medium 80A. Here, the duplicating reference beam 85b is irradiated from the same incident direction as the master disc producing reference beam 76b used as shown in FIG. 7 when the duplicating disc 60B is produced. That is, with reference to the center of the replication master 60B (in FIG. 11, the rotation center of the spindle motor rotation shaft 98a), the replication reference light 85b is irradiated radially, and the replication master 60B and the replication hologram recording medium 80A. With the rotation, holograms are sequentially formed, and a recorded duplicate hologram recording medium 80B is finally manufactured. That is, the replica hologram recording medium 80A is moved in the rotational angle direction (indicated by the arrow R2 in FIG. 15) along with the rotation of the spindle motor rotating shaft 98a, and the reference light 85b for replication is scanned one-dimensionally. is doing.

  More specifically, duplication is performed according to the following procedure. The duplicate master 60B and the duplicate hologram recording medium 80A are rotated together by the rotation of the spindle motor rotating shaft 98a. At this time, the belt-like duplication reference beam 85b reflected by the mirror 91b simultaneously irradiates the outer circumference from the inner circumference of the duplication master 60B. In this way, it is possible to finally obtain a duplicate hologram recording medium 80B obtained by duplicating holograms in the entire area where duplication of the duplication master 60B is scheduled. In this embodiment, the laser light source 90 has a function of generating the reference light 85a for duplication, and the spindle motor 98, the prism 62d, the anamorphic prism 92a, the anamorphic prism 92b, and the mirror 91b are duplicated in a predetermined area of the duplication master 60B. Each has a function of irradiating the reference light 85a, and both are configured as a part of the duplication reference light generating means.

  By using such a duplicate hologram recording medium manufacturing apparatus 150, the duplicate hologram recording medium 80B can be obtained simply and at high speed by rotating the spindle motor rotating shaft 98a once.

(Regarding the production technique of the third embodiment for producing a duplicate hologram recording medium from the duplicate master 60C and the duplicate master 60D)
As a technique for manufacturing a replica hologram recording medium using the replica master 60C and the replica master 60D, a replica hologram recording medium manufacturing apparatus 160 of the third embodiment and a manufacturing method of the third embodiment using the manufacturing apparatus will be described. In this manufacturing apparatus and manufacturing method, a hologram recording medium on which a hologram is recorded is obtained by irradiating a light beam in a range covering the entire master 60C for duplication or the master 60D for duplication at a time without scanning the light beam. It is something that can be done.

  FIG. 16 shows a duplicate hologram recording medium manufacturing apparatus 160 of the third embodiment. The replica hologram recording medium manufacturing apparatus 160 of the third embodiment includes a laser light source 90, an anamorphic prism 92a, an anamorphic prism 92b, an anamorphic prism 92c, an anamorphic prism 92d, a mirror 91c, a prism 62e, and a replica master 60C or replica master 60D. FIG. 16 representatively shows a duplication master 60C) as a main component. All of the above-described components are fixed to the reference table. The width of the light beam from the laser light source 90 is expanded on the plane including the Y axis and the Z axis shown in FIG. 16 by the anamorphic prism 92a and the anamorphic prism 92b. Further, the width of the light beam is expanded by the anamorphic prism 92c and the anamorphic prism 92d on the plane including the X axis and the Y axis shown in FIG. The duplicating reference beam is obtained as the duplicating reference beam 85c. Here, the four anamorphic prisms of the anamorphic prism 92a to the anamorphic prism 92d are used so that the duplication reference light 85c can irradiate the entire surface of the duplication master 60C or the duplication master 60D. Therefore, when the size of the area of the replication master 60C or the replication master 60D irradiated with the replication reference light 85c is small, a sufficient irradiation area of the replication reference light 85c is achieved by the anamorphic prism 92a and the anamorphic prism 92c. Can be secured.

  The wavelength of the duplicating reference beam 85c has a wavelength substantially equal to the wavelength of the master disc manufacturing reference beam 76b. The prism 62e is configured to cover the entire surface of the replication master 60C or the replication master 60D. As shown in FIG. 16, the thickness of the prism 62e (in the Y-axis direction, which is the direction in which the replication reference light 85c travels) Although the distance in the Z-axis direction changes, the thickness of the prism 62e (distance in the Z-axis direction) does not change in the X-axis direction.

  FIG. 17 shows a relationship between the duplicate hologram recording medium 80A and the duplication reference light 85c expanded in two dimensions by a perspective view seen from the upper side of the duplicate hologram recording medium 80A. Here, the replica reference light 85c is produced from the same incident direction as that of the master disc reference light indicated by the arrow as shown in FIG. 9D when the replica master disc 60C or the replica master disc 60D is manufactured. Irradiated. That is, by irradiating the duplication reference beam 85c, the duplication hologram recording medium 80C is manufactured when the duplication master 60C is used, and the duplication hologram recording medium 80D is produced when the duplication master 60D is used. . In this embodiment, the laser light source 90 has a function of generating the reference light 85a for duplication, and each of the mirror 91c, the anamorphic prism 92a, the anamorphic prism 92b, the anamorphic prism 92c, and the anamorphic prism 92d is a predetermined of the duplication master 60B. Each of the regions has a function of irradiating the replication reference light 85a, and both are configured as a part of the replication reference light generation means.

  By using such a replica hologram recording medium manufacturing apparatus 160, the replica hologram recording medium 80A is disposed in the vicinity of the replica master 60C or the replica master 60D, and the replica reference light 85c is irradiated through the prism 62e. Thus, the duplicate hologram recording medium 80C or the duplicate hologram recording medium 80D can be obtained instantaneously.

  Further, in such a duplicate hologram recording medium manufacturing apparatus 160, a plurality of duplicate hologram recording media 80A are continuously moved by using a transfer device (not shown), and as shown in FIG. By stopping the movement above the master 60D and irradiating the duplicating reference beam 85c, it is possible to continuously obtain the duplicate hologram recording medium 80C or the duplicate hologram recording medium 80D on which the hologram is formed. In such a batch process, a mechanism for stopping the movement on the upper side of the replica master 60C or the replica master 60D is not shown, but is normally used in the manufacturing process of various products. For example, the lift of the duplicate hologram recording medium 80A is lifted and moved, and the lift is lowered when it is detected by an optical sensor (not shown) that the duplicate hologram recording medium 80A is positioned on the duplicate master 60C or the duplicate master 60D. The relative position between the duplicate hologram recording medium 80A and the duplicate master 60C or the duplicate master 60D is set to a predetermined position, and functions as an embodiment of the positioning means.

  Each of the replica hologram recording medium 80B to the replica hologram recording medium 80D manufactured by the manufacturing apparatus of the first to third embodiments and the manufacturing method of the first to third embodiments is a large amount as a replica hologram recording medium. Can be replicated and distributed. In this case, if a specific area of the duplicate hologram recording medium is left as an unrecorded area of the hologram, a person who obtains such a duplicate hologram recording medium writes necessary recording data in the unrecorded area ( Can be added).

  Further, in the case where no additional writing is performed on the replica hologram recording medium 80B or replica hologram recording medium 80D manufactured by the manufacturing apparatus of the first embodiment to the third embodiment or the manufacturing method of the first embodiment to the third embodiment, It is desirable to perform post-processing by irradiating the hologram recording medium with light having poor coherence. This is a process of changing all the monomers remaining in the duplicate hologram recording medium into polymers. The light to be irradiated may be light having a wavelength at which the medium is exposed and has poor coherence. For example, LED light may be collectively irradiated. As a result, additional recording cannot be performed on the duplicate hologram recording medium.

  The duplicate hologram recording medium manufactured by using the manufacturing apparatus according to the first to third embodiments described above is a transmission hologram recording medium, and the hologram recording medium is irradiated with reference light to reproduce the duplicate hologram. The recorded data corresponding to the hologram recorded from the diffracted light generated on the same side as the reference light transmitted through the recording medium 80B is reproduced. In the case of a hologram recording medium that can be reproduced by the recording / reproducing apparatus having the optical unit 10 shown in FIG. 1, the hologram recording medium is further completed by forming a reflective film in contact with the holding substrate 60b. Here, the reflective film can be formed by sputtering, for example. This reflection film is for irradiating a reference light for reproduction from the holding substrate 60c side to read a signal recorded on the hologram recording medium.

  The duplicate hologram recording medium having the reflection film on the duplicate hologram recording medium 80B obtained as described above can be easily reproduced by the ordinary reproduction method of the hologram reproducing apparatus having the optical unit 10 shown in FIG. is there. A duplicate hologram recording medium having a reflection film on the duplicate hologram recording medium 80C obtained as described above is obtained by the image sensor 29 as described above in the hologram reproducing apparatus having the optical unit 10 shown in FIG. Reproduction can be performed by a reproduction method that rotates a reproduction image. A duplicate hologram recording medium having a reflection film on the duplicate hologram recording medium 80D can be easily reproduced by a normal reproduction method in the hologram reproducing apparatus having the optical unit 10 shown in FIG.

(Modification of Embodiment of Manufacturing Method of Duplicating Master and Duplicating Hologram Recording Medium)
Various modified embodiments of the above-described embodiment will be described below.

  FIG. 18 is a partially enlarged view of FIG. 2, but shows an example in which the condensing position of the modulated coaxial light 75 b is different. In the above embodiment, the modulated coaxial light 75b is once condensed and then irradiated to the recording layer 60a of the duplication master 60A. However, in FIG. 18, the recording layer 60a is irradiated before the modulated coaxial light 75b is condensed. It is made to do. The aberration is corrected by the objective lens 39 without using the dummy glass. Instead, an objective lens and a dummy glass (see, for example, the objective lens 38 and the dummy glass 61a in FIG. 3) are used. It is good as a thing. In this case, as apparent from comparison with FIG. 3, the duplication master 60A is arranged in the opposite direction to that of FIG. 3, the holding substrate 60b side is arranged on the prism 62a side, and the holding substrate 60c side is the objective lens. It is arranged on the 39 side. In addition, by adopting the oil 63, the optical reflection arrangement can be ensured and total reflection can be effectively suppressed. The duplication master disc manufactured by varying the condensing position of the modulated coaxial light 75b in this way has the same hologram shape as the duplication master disc 60B or duplication master disc 60D. Here, the method of changing the condensing point can be freely performed by adjusting the target value (offset) of the control system by the feedback loop when the above-described stigma method is adopted. A manufacturing apparatus and a manufacturing method for manufacturing a replica hologram recording medium from such replica master 60B or replica master 60C can be used by using any of the techniques of the above-described embodiments.

  FIG. 19 shows an example in which a master-producing reference beam 76b from the mirror 45a is irradiated from above the duplication master 60A without using the mirror 45b, although the optical unit substantially similar to FIG. 2 is used. The prism 65 is installed near the holding substrate 60b of the duplication master 60A, and the prism 62a is installed near the holding substrate 60c. It is more desirable to fill the gaps between the holding substrates and the prisms with oil 63 in order to achieve an optically close arrangement. The prism 65 is used to guide the master production reference beam 76b into the holding substrate 60b of the duplication master 60A. The prism 65 is arranged at a position that does not obstruct the progression of the modulated coaxial light 75b. Further, the prism 62a is for causing the master-producing reference beam 76b to escape from the duplication master 60A. In the absence of the prism 62a, it is difficult for the master-producing reference beam 76b from above in FIG. 19 to be totally reflected by the holding substrate 60c and escape. If it cannot be removed, the master-producing reference beam 76b is multiple-reflected at the upper and lower interfaces of the duplicating master 60A, and the monomer is wasted.

  Even when the prism 62a and the prism 65 are not provided, the master-producing reference beam 76b can pass through the holding substrate 60b and the holding substrate 60c. However, the incident angle of the reference light for manufacturing master 76b on the holding substrate 60b should be closer to the perpendicular to the surface of the holding substrate 60b so as not to be reflected by the holding substrate 60b and the holding substrate 60c. For example, when the refractive index of the holding substrate 60b is 1.5, total reflection is performed on the surface of the holding substrate 60b unless the angle is within 41.8 ° with respect to the normal from the surface of the holding substrate 60b. It will occur. On the other hand, when the prism 62a and the prism 65 are provided, even if the angle of incidence of the master production reference beam 76b is 41.8 ° or more, total reflection does not occur, and the holding substrate 60b is effectively formed. Incident.

  Further, the relationship between the focal position of the modulated coaxial light 75b and the upper and lower arrangements of the duplication master 60A (the arrangement of which holding substrate 60b or holding substrate 60c is the incident side of the modulated coaxial light 75b) is the result. The hologram shown in FIG. 19 is not limited to the combination shown in FIG. 19 as long as the hologram form formed on the duplicate hologram recording medium obtained as a product is a combination that can obtain the above-described duplicate hologram recording medium 80B to duplicate hologram recording medium 80D. Thus, when the prism 65 is also arranged on the upper surface of the replica master 60A, the master-producing reference beam 76b can be guided from above the replica master 60A in the same manner as the modulated coaxial light 75b. The optical path of the manufacturing reference beam 76b can be made simpler, the cost of manufacturing equipment can be reduced, and the alignment of the master manufacturing reference beam 76b can be facilitated to improve the reliability.

  FIG. 20 is a partially enlarged view of the hologram forming region in the case where the condensing position of the modulated coaxial light is different from that shown in FIGS. 3 and 18. While adopting the same arrangement relationship between the replication master 60A and the prism 62a as shown in FIG. 18, the condensing point of the modulated coaxial light 75b is set to be farther from the replication master 60A. Such setting can be performed by adjusting the target value (offset) of the control system by the feedback loop when the astigma method is adopted. In the case of using the duplication master 60E formed in such a manner of condensing the modulated coaxial light 75b, the above-described technology for producing a duplicate hologram recording medium can be employed. It can be different from the thing.

  FIG. 21 is a partially enlarged view of the hologram forming region in the case where the condensing position of the modulated coaxial light is different from those shown in FIGS. 3, 18, and 20. This shows a method for manufacturing a duplicate hologram recording medium using the master for duplication 60E, which is different from any method for manufacturing the duplicate hologram recording medium described above. Here, the holding substrate 80b side of the duplicate hologram recording medium 80E and the holding substrate 60b side of the duplication master 60E are arranged so as to face each other. In addition to the recording layer 80a, the holding substrate 80b, and the holding substrate 80c, the duplicate hologram recording medium 80E before the hologram is formed is provided with a reflective layer 80d from the beginning. For example, a thickness of the holding substrate 80b is 0.5 mm, and a thickness of the holding substrate 80c is 0.1 mm, for example. Since the condensing point of the modulated coaxial light 75b is set to be farther from the replica master, and the hologram is formed on the replica master 60E, for example, replication is performed using the replica reference light 85a. The hologram formed by the diffracted light 86 generated in this case is satisfactorily formed on the recording layer 80a at the back of the thick holding substrate 80b. If such a method for producing a duplicate hologram recording medium is employed, the duplicate hologram recording medium can be provided with the reflective layer 80d in advance, so that the production yield is obtained when the reflective layer 80d is formed after the hologram is duplicated. However, there is an advantage that this is not the case.

  The duplication hologram recording medium duplication method shown in FIG. 21 is an example in the case of using duplication reference light 85a that is two-dimensionally scanned, but in the case of using duplication reference light 85b that is one-dimensionally scanned. Any method in the case of using the irradiation reference beam 85c to be irradiated can be employed, and the above-described technology can be employed as a post-processing technology using a monomer as a polymer.

(Modification of the shape of the master for duplication and the shape of the duplicate hologram recording medium)
The above description has been made on the case where the shape of the replica master and the shape of the replica hologram recording medium are both discs. However, the shape of the replica master and the shape of the replica hologram recording medium are card shapes (rectangular or square). ). In this case as well, it is possible to manufacture a replica master and a replica hologram recording medium using the same principle as described above, and further, a replica master manufacturing apparatus and a replica hologram using the same principle as described above. A recording medium manufacturing apparatus can be provided.

  In other words, in the production of the master for duplication, in the disk shape, the hologram was formed on the two-dimensional surface of the master for duplication by moving the light spot in the tangential direction (circumferential direction) and radial direction (radial direction). In the card shape, a hologram is formed on a two-dimensional surface by scanning the relative position between the light spot and the card-shaped duplication master in two directions perpendicular to the X axis and the Y axis. And, in the manufacturing apparatus of the replica master, the configuration of the manufacturing apparatus in the above-described disk shape is the same as that provided with a mechanism for changing the relative position of the light spot and the card-shaped replica master in the X-axis and Y-axis directions. It can be adopted as it is.

  In the production of a duplicate hologram recording medium, when producing a duplicate hologram recording medium by scanning a light spot two-dimensionally, the light in the tangential direction (circumferential direction) and radial direction (radial direction) is used in the disk shape. The hologram was formed on the duplicate hologram recording medium by moving the spot. However, in the card shape, the relative position between the light spot and the card-shaped duplication master is moved in two directions perpendicular to the X and Y axes. A hologram is formed on the hologram recording medium. In the case of producing a duplicate hologram recording medium by scanning a light beam in a one-dimensional direction, the one-dimensional light beam extending in the one-dimensional direction is scanned in a direction perpendicular to the direction in which the light beam extends to produce a duplicate hologram recording medium. A hologram is formed. In addition, when a light beam having a two-dimensional area is used, batch irradiation is performed similarly to the disk shape.

  Further, in the replica master manufacturing apparatus, in the case of a disk shape, an operation such as synchronization of the incident direction of the reference light and the rotation of the replica master makes it easy to manufacture the replica hologram recording medium. Although it is required, such a complicated processing is not required for the card shape that operates based on the orthogonal coordinate system of the X axis and the Y axis, so the mechanism of the manufacturing apparatus for the master for duplication is simplified. it can.

  Each of the above-described embodiments is merely one embodiment of the present invention, and the present invention is not limited to the above-described embodiment. For example, the shapes of the replica master and the replica hologram recording medium are not limited to a disc shape or a card shape, and the replica hologram recording medium transmits without being limited to only having a reflective film. The structure of each layer of the master for duplication and the hologram recording medium for duplication is not limited to the above-described form, and embodiments of modifications and combinations within the same technical idea are also possible. Naturally, it is included in the scope of the present invention.

It is a conceptual diagram of the optical part as a principal part of the hologram recording apparatus of a co-axial system. It is a conceptual diagram of the optical part as a principal part of the manufacturing apparatus of the master for duplication. FIG. 3 is a partially enlarged view of FIG. 2. It is a graph which shows the relationship between an incident angle and a reflectance. It is a conceptual diagram of the optical part as a principal part of the manufacturing apparatus of the master for duplication. It is a figure which shows the relationship between the hologram formation area | region seen from the surface side of the master for duplication, and the reference light for master disc manufacture. It is a figure which shows the relationship between the hologram recorded in the position from which the rotation angle of the original disk for replication differs, and the reference light for an original disk manufacture. It is a conceptual diagram of the optical part as a principal part of the manufacturing apparatus of the master for duplication. It is a figure which shows the relationship between the hologram recorded in the position from which the rotation angle of the original disk for replication differs, and the reference light for an original disk manufacture. It is a conceptual diagram of the optical part as a principal part of the manufacturing apparatus of the master for duplication. It is a conceptual diagram of a duplicate hologram recording medium manufacturing apparatus. It is a figure which shows the reference light for duplication formed as a light spot by the perspective view seen from the upper side of the duplication hologram recording medium. It is the elements on larger scale of FIG. It is a conceptual diagram of a duplicate hologram recording medium manufacturing apparatus. It is a figure which shows the reference light for duplication formed as a belt of light by the perspective view seen from the upper side of the duplication hologram recording medium. It is a conceptual diagram of a duplicate hologram recording medium manufacturing apparatus. It is a figure which shows the reference light for duplication expanded two-dimensionally with the perspective view seen from the upper side of the duplication hologram recording medium. FIG. 4 is a partially enlarged view of a hologram forming region when the position of condensing modulated modulated light is different from that shown in FIG. 3. It is a figure which shows the example which irradiates the reference light for original disc manufacture from the upper direction of the original disc for duplication using the optical part substantially the same as FIG. FIG. 19 is a partially enlarged view of a hologram forming region in a case where the condensing position of the modulated coaxial light is different from that shown in FIGS. 3 and 18. FIG. 21 is a partial enlarged view of a hologram formation region when the position of the focused focused coaxial light is different from that shown in FIGS. 3, 18, and 20.

Explanation of symbols

10, 100, 110, 120, 130, 135 Optics, 20, 30, 90 Laser light source, 22, 32a, 32b Polarizing beam splitter, 23, 33a, 33b Spatial light modulator, 24, 26, 34, 36 Fourier transform Lens, 25, 35 Iris, 27 1/4 wave plate, 40 Half wave plate, 41, 42 1/4 wave plate unit, 28, Objective lens, 29, Image sensor, 38, 39 Objective lens, 44 Aperture, 45a, 45b Mirror, 47a, 47b Mounting member, 48 Spindle motor, 48a Spindle motor rotation shaft, 48b Spindle motor fixing part, 48c Rotation angle detector, 49 Moving base, 50 Hologram recording medium, 50a, 60a, 80a Recording layer, 50b 50c, 60b, 60c, 80b, 80c holding substrate, 0d reflective layer, 50e protective layer, 51 optical unit rotation motor, 51a optical unit rotation motor rotating shaft, 51b optical unit rotation motor fixing unit, 51c rotation angle detector, 52 control unit, 53, 54 wavelength plate unit actuator, 60A, 60B, 60C, 60D, 60E Duplicating master, 61a, 61b Dummy glass, 62a, 62b, 62c, 62d, 62e Prism, 63 Oil, 71 Movable optical part rotating motor, 71a Rotating shaft, 71b Fixed part, 73, 74 Pulley 75a Coaxial light, 75b Modulated coaxial light, 76a, 76b Reference light for master production, 77 Moving part rotation detector, 80A, 80B, 80C, 80D Hologram recording medium, 85a, 85b, 85c Duplicate reference light, 91a, 91b, 91c Mirror, 92a, 92b, 92c 92d anamorphic prism, 97a, 97b attachment member, 98 a spindle motor, 98a a spindle motor rotation shaft, 140, 150, 160 duplicate hologram recording medium manufacturing apparatus, 145a, 145b, 145c, 145d mirror, Ha, Hb, Hc, Hd hologram

Claims (14)

An apparatus for producing a master for duplication used for duplicating a hologram carrying recorded data on a duplicate hologram recording medium,
A beam splitter that splits a light beam from a laser light source into a coaxial beam and a reference beam for master production;
A spatial light modulator that performs modulated spatial light on the coaxial light and generates modulated coaxial light in which predetermined reference light and signal light corresponding to recording data are arranged coaxially;
Condensing means for condensing the modulated coaxial light on the recording layer of the duplication master,
A prism that is optically arranged in close contact with the surface of the master for duplication, guides the reference light for master production to the recording layer on which the reference light for master production is incident and the modulated coaxial light is collected;
Hologram forming position moving means for moving the position of the recording layer where the hologram is formed by interference between the master production reference light and the modulated coaxial light; and
An apparatus for producing a master for duplication comprising: The condensing means and the prism are configured so that the modulated coaxial light is irradiated from one surface of the replica master, and the master manufacturing reference light is irradiated from the other surface of the replica master. It is arranged so as to sandwich the master for duplication,
2. The optical disk forming device according to claim 1, further comprising an optical path forming unit that guides the master-producing reference light to the prism at an incident angle that causes total reflection on the back side of the one surface of the replica master. Production equipment for master for duplication. The condensing means and the prism are arranged on the same side of the duplication master so that the modulated coaxial light and the master production reference light are irradiated from the same side of the duplication master. ,
2. The duplication master production apparatus according to claim 1, further comprising an optical path forming unit that guides the master production reference light to the prism. In order to optically closely arrange the surface of the master for duplication and the prism,
2. The apparatus for producing a master for duplication according to claim 1, wherein a gap between a surface of the master for duplication and the prism is filled with an optical contact medium that transmits a light beam.   2. The apparatus for producing a master for duplication according to claim 1, wherein the hologram forming position moving means has a spindle motor that rotates around a center point of the master for duplication having a circular plate shape. The hologram forming position moving means has a spindle motor that rotates around a center point of the master for duplication that is a circular plate,
2. The apparatus for manufacturing a master for duplication according to claim 1, wherein the direction of incidence of the reference light for manufacturing the master and the position of the prism are moved in synchronization with a rotation angle of a spindle motor rotating shaft of the spindle motor. . The hologram forming position moving means has a spindle motor that rotates around a center point of the master for duplication that is a circular plate,
In synchronization with the rotation angle of the spindle motor rotating shaft of the spindle motor, the incident direction of the reference light for manufacturing the master, the position of the prism, the position of the modulated coaxial light around the optical axis, and the spatial light modulator The apparatus for producing a master for duplication according to claim 1, wherein an image displayed on the disk is rotated. A replica hologram recording medium manufacturing apparatus for replicating a hologram carrying recording data formed on a replica master to a replica hologram recording medium,
Positioning means for setting a relative position between the replication master and the replication hologram recording medium;
Generating a reference light for duplication, and irradiating the reference light for duplication to irradiate the predetermined area of the recording layer of the master for duplication with the reference light for duplication;
A prism that is optically arranged in close contact with the surface of the master for duplication to guide the reference light for duplication to the recording layer of the master for duplication;
The duplication master is
The duplication reference light transmitted through the recording layer is reflected again to the recording layer and has a holding substrate that transmits diffracted light from the recording layer.
An apparatus for producing a duplicate hologram recording medium. The replication reference light generating and irradiating means is
A laser light source for generating the spot-shaped reference light for replication;
A spindle motor for rotating the replica master and the replica hologram recording medium to irradiate the predetermined area with the replica reference light;
A light spot moving means for changing the position of the reference light for duplication in the spot shape irradiated on the duplication master in the radial direction of the duplication master,
An apparatus for producing a duplicate hologram recording medium according to claim 8. The replication reference light generating and irradiating means is
A laser light source for generating the spot-shaped reference light for replication;
An anamorphic prism for shaping the spot-shaped reference light for duplication into the band-like reference light for duplication;
A spindle motor for rotating the replica master and the replica hologram recording medium to irradiate the predetermined area with the replica reference light;
An apparatus for producing a duplicate hologram recording medium according to claim 8. The replication reference light generating and irradiating means is
A laser light source for generating the spot-shaped reference light for replication;
A first anamorphic prism for shaping the spot-shaped duplication reference light into a band-like duplication reference light;
A second anamorphic prism configured to extend the length of the strip-shaped reference light for duplication in the short direction to shape the reference light for duplication in a range covering the predetermined area;
An apparatus for producing a duplicate hologram recording medium according to claim 8. A disc-shaped duplication master used for duplicating a hologram carrying recorded data on a duplicate hologram recording medium,
A recording layer on which the hologram is formed;
Each of which is disposed on both sides of the recording layer to hold the recording layer, each having a disc-shaped holding substrate,
One of the holding substrates is formed in a cone shape in which the thickness of the center point of the disk shape is the thickest, or formed in a cone shape in which the thickness of the center point of the disk shape is the smallest, and functions as a prism. A master for duplication. A method of manufacturing a master for duplication used for duplicating a hologram carrying recording data on a duplication hologram recording medium,
The light beam from the laser light source is divided into a coaxial beam and a reference beam for master production,
Spatial light modulation is performed on the coaxial light to generate modulated coaxial light in which predetermined reference light and signal light corresponding to recording data are arranged coaxially,
Condensing the modulated coaxial light on the recording layer of the master for duplication,
The modulated coaxial light is led to the recording layer without being totally reflected by the prism optically arranged on the surface of the replica master without reflecting the master reference light;
Moving the position of the recording layer on which the hologram is formed by interference between the reference light for master production and the modulated coaxial light,
A method for manufacturing a replica master, wherein a hologram is formed in a predetermined range of the replica master. A method for producing a duplicate hologram recording medium for duplicating a hologram formed on a duplication master carrying recorded data on a duplicate hologram recording medium,
The relative position between the replica master and the replica hologram recording medium is a predetermined arrangement,
A prism is optically closely arranged on the surface of the master for reproduction,
Generating a reference light for duplication that irradiates the recording layer on which the hologram of the master for duplication is formed;
The duplication reference light is incident on the duplication master without being totally reflected by the prism,
A method for producing a duplicate hologram recording medium, wherein the duplicate hologram recording medium is irradiated with diffracted light from the recording layer of the duplication master.

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