JP2012014804A - Manufacturing device of master disk and method for manufacturing master disk - Google Patents

Abstract

[PROBLEMS] A master disk manufacturing apparatus and master disk manufacturing method for replicating a hologram optical element for an optical pickup, and the substrate thickness of the master disk and the recording material for replication and the diffraction angle of the hologram optical element can be freely designed. Provided are a master manufacturing apparatus and a master manufacturing method capable of forming a master that does not require a condenser lens immediately before the master during duplication.
An apparatus for manufacturing a master disc includes a light source 80 that emits a light beam, and a beam that splits the light beam emitted from the light source 80 into a laser beam L1 and a laser beam L2 that travels in a direction different from the traveling direction of the laser beam L1. The laser beam L2 is reflected so that the splitter 81, the objective lens 87 that collects the laser beam L1 and becomes the recording beam L3, and the recording beam L3 and the laser beam L2 intersect, and the reflection direction of the laser beam L2 And a retainer 93 that holds the master recording material 90 so that the recording light L3 and the laser light L2 intersect at the master recording material 90.
[Selection] Figure 14

Description

  The present invention relates to a hologram optical element master manufacturing apparatus and master master manufacturing method.

  Multiple standard optical discs are widely used, such as CD (Compact Disc), DVD (Digital Versatile Disc), and BD (Blu-ray Disc), which have different wavelengths of light sources for optical information recording and reproduction. When this recording / reproducing device is incorporated into an electronic device such as a notebook computer, it is required to be downsized and thinned, and the optical pickup device corresponding to each wavelength in the recording / reproducing device is also required to be downsized and thinned. It has been. Further, when recording / reproducing devices for each optical disc are integrated and a recording / reproducing device capable of recording / reproducing all the optical discs is incorporated, the optical pickup is further required to be thinner. In order to provide a thin optical pickup device, a technique has been proposed in which diffractive optical elements are used to diffract return light from an optical disk into a focus signal light receiving element and a track signal light receiving element.

  FIG. 15 shows a schematic diagram of an optical pickup device. The optical pickup device is configured as follows, for example. The optical pickup device includes semiconductor lasers 10 and 11 as light sources, a dichroic mirror 12, a collimator lens 9, a diffraction grating 8, a beam splitter 5, a quarter wavelength plate 3, an objective lens 2, and a sensor lens. 4, a diffractive optical element 6, and a light receiving element 7. In the optical pickup device, light emitted from the semiconductor laser 10 is made into substantially parallel light by the collimator lens 9 and diffracted by the diffraction grating 8 into at least 0th order transmitted light and first order diffracted light. The light emitted from the diffraction grating 8 passes through the beam splitter 5, is converted into circularly polarized light by the quarter wavelength plate 3, is condensed by the objective lens 2, and is irradiated onto the optical disk 1. The semiconductor laser 11 that is a light source has a wavelength different from that of the semiconductor laser 10, is coupled to the optical axis of the semiconductor laser 10 by the dichroic mirror 12, and is similarly irradiated onto the optical disk 1. The reflected light from the optical disk 1 is again converted into linearly polarized light rotated by 90 ° with respect to the incident time by the quarter-wave plate 3, reflected by the beam splitter 5, focused by the sensor lens 4, and partially diffracted by the diffractive optical element 6. And enters the light receiving element 7. Each of the light receiving elements 7 is for a focus signal or a track signal.

  In order to provide a thinner optical pickup device, it is necessary to increase the diffraction angle of the diffractive optical element 6 related to light beam separation, but in order to diffract short wavelength return light with a large diffraction angle, the diffractive optical element It is necessary to reduce the pitch of 6 and it is very difficult to manufacture by photolithography. For this reason, attention has been paid to using a hologram optical element in which a refractive index grating is recorded on an optical recording material by a two-beam interference method as a diffractive optical element of an optical pickup device as disclosed in JP-A-2005-11478. The hologram optical element created by the two-beam interference method can be designed with a free diffraction angle, and can also realize high diffraction efficiency. In the relief type hologram element produced by the photolithography technique, the reflected light from the non-reproducing layer is diffracted on the relief type hologram element when the multilayer disk is used, and stray light is generated. In the volume hologram optical element created by the two-beam interference method, the reflected light from the non-reproducing layer is not diffracted on the volume hologram optical element because the phase state is different from the reflected light from the reproducing layer. It is also possible to suppress the stray light.

  Such a hologram optical element is produced through a sector mask for separating the light beam for a focus signal or a track signal, and a light beam equivalent to the zero-order transmitted light that is the basis of the optical pickup and incident on each light receiving element. This is performed by causing the two light beams to be interfered with each other on the optical recording material. In order to manufacture a hologram optical element having focal positions at a plurality of locations, a complicated manufacturing process is required. Therefore, a master for manufacturing the optical element is prepared in advance, and the hologram is formed via the master. A method of replicating and mass-producing optical elements has been attracting attention. In Japanese Patent Application Laid-Open No. 2005-11478, the sector mask is disposed immediately before the recording material, a master is produced by two-beam interference exposure, and the hologram optical element is duplicated. More specifically, the master and the duplication recording material are brought into close contact with each other, and the two light fluxes of the zero-order transmitted light and the first-order diffracted light generated from the zero-order transmitted light of the master are similarly interfered on the duplication recording material. It is carried out. In the replication method described in Japanese Patent Application Laid-Open No. 2005-331758, a gap is formed between hologram regions on the master so that the 0th-order transmitted light and the first-order diffracted light of the master have a desired overlap on the recording material for replication. Provided.

JP 2005-11478 A JP 2005-331758 A

  Thus, in producing a hologram optical element by the two-beam interference method, since the two light beams are both focused light and are not circular light beams cut out by a sector mask, they are superposed to form a desired hologram optical element. Is difficult. In Japanese Patent Application Laid-Open No. 2005-11478, the master and the recording material for duplication are made in close contact with each other, and duplication is performed. However, if the angle between the two light beams is increased so as to increase the diffraction angle, the master in between the close contact is obtained. When the substrate for recording material for duplication and duplication is thick, the two light beams are separated by an optical path corresponding to the thickness of the substrate, so that it is difficult to superimpose the two light beams in the recording material for duplication. Thus, the problem is that the thickness and diffraction angle of the substrate cannot be designed sufficiently freely. Further, as a different duplicating method, in Japanese Patent Laid-Open No. 2005-11478, a relay lens system is assembled between the master and the recording material for duplication, so that the 0th-order transmitted light and the first-order diffracted light of the master are duplicated in the recording material. A two-beam interference exposure method is described. In this method, the optical axis adjustment between the relay lens and the master disk is not easy, and one pair of relay lenses is required for one hologram optical element duplication, so that duplication is inefficient.

  Further, in the duplication method described in the example of Japanese Patent Application Laid-Open No. 2005-331758, the 0th-order transmitted light and the 1st-order diffracted light of the master are overlapped on the master so as to overlap each other as desired. Although there is a gap between the hologram areas, since a condensing lens is used when reproducing the master, one condensing lens is required for one master. It is difficult to adjust the optical axis. Further, when a plurality of the same masters are prepared in mass production, the same number of condensing lenses as the masters are required, and the duplication is inefficient.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a master disk manufacturing apparatus and a master disk manufacturing method for replicating a hologram optical element for an optical pickup. An object of the present invention is to provide a master manufacturing apparatus and a master manufacturing method that can freely design the diffraction angle of an element and can form a master that does not require a condensing lens immediately before the master during replication.

  The master production apparatus according to the present invention is a master production apparatus for duplicating a hologram optical element. The master manufacturing apparatus includes a light source that emits a light beam, a branching device that branches the light beam emitted from the light source into a first light flux and a second light flux that travels in a direction different from the traveling direction of the first light flux, and the first light flux And a reflection device capable of adjusting the reflection direction of the second light beam and the recording light and the second light beam so that the recording light and the second light beam intersect each other. A holder that holds the photosensitive material so that the two light beams intersect with each other in the photosensitive material and a control unit that controls driving of the reflecting device are provided. The holder holds the photosensitive material so that the inclination angle of the photosensitive material with respect to the recording light can be adjusted, and holds the photosensitive material rotatably. The control unit drives the reflecting device in accordance with the tilt angle and the rotation of the photosensitive material so that the incident direction in which the second light beam enters the photosensitive material becomes a specific constant direction.

  Preferably, the reflection device is provided so as to be capable of advancing and retreating with respect to the second light beam emitted from the branching device, a position where the second light beam emitted from the branching device can be reflected toward the photosensitive material, and the second light beam. The 1st reflective mirror provided so that it could move between the positions away from was included. The reflection device includes a second reflection mirror that reflects the second light beam when the first reflection mirror moves away from the second light beam, and a reflection surface that reflects the second light beam reflected by the second reflection mirror. A rotation reflection mirror having a rotatable surface, and a third reflection mirror that reflects the second light beam reflected by the rotation reflection mirror toward the photosensitive material.

  The incident direction of the second light beam reflected by the first reflecting mirror with respect to the photosensitive material is a specific constant direction, and the incident direction of the second light beam reflected by the third reflecting mirror with respect to the photosensitive material is a specific constant direction. Thus, the rotary reflection mirror is rotated in accordance with the inclination angle and the rotation of the photosensitive material.

  Preferably, the holder moves so that the distance between the focal point of the recording light condensed by the lens and the photosensitive material is constant.

  Preferably, the master manufacturing apparatus further includes a plurality of sector masks. The sector mask is disposed in the path of the first light beam or recording light. Each sector mask is formed with a hole through which the first light beam or the recording light passes, each hole having a different shape, and the sector mask is replaced in accordance with the inclination angle and the rotation of the photosensitive material.

  The master disk manufacturing method according to the present invention includes a light source that emits a light beam, and a branching device that branches the light beam emitted from the light source into a first light flux and a second light flux that travels in a direction that intersects the traveling direction of the first light flux. The second light beam is reflected so that the recording light condensed by the lens and the second light beam intersect, and the reflection direction of the second light beam is changed. An adjustable reflection device, a holder that holds the photosensitive material, and holds the photosensitive material so that the first light beam and the second light beam intersect in the photosensitive material, and a control unit that controls driving of the reflection device. The process of preparing the manufacturing apparatus of the master provided with is provided. Further, the master production apparatus includes a step of holding the photosensitive material in the holder, and a step of forming interference fringes on the photosensitive material by intersecting the recording light and the second light beam reflected by the reflecting device with the photosensitive material. With.

  According to the hologram optical element master manufacturing apparatus and the master manufacturing method of the present invention, when replicating a hologram optical element for an optical pickup, the substrate thickness of the master or the duplication recording material, and the diffraction angle of the hologram optical element A master that can be freely designed can be obtained. In addition, a master disc capable of replicating a hologram optical element that does not require a condenser lens immediately before the master disc can be manufactured.

(A) is a top view which shows the outline | summary of a hologram optical element, (b) is a side view of a hologram optical element. (A) is a top view which shows typically the original disk of a hologram optical element, (b) is a side view which shows typically the manufacturing process of a hologram optical element. It is a schematic diagram which shows the original disk of the hologram optical element of this invention. It is a schematic diagram which shows the manufacturing method of the hologram optical element using the original disc of this invention. It is a schematic diagram which shows the mass-production method of the hologram optical element using the original disc of this invention. It is a schematic diagram which shows the preparation method of the original disc of this invention, and a 1st process. It is a structural example of the sector mask for producing the original disc of this invention. It is a schematic diagram which shows the preparation method of the original disk of this invention, and a 2nd process. It is a schematic diagram which shows the preparation method of the original disk of this invention, and a 3rd process. It is a schematic diagram which shows the preparation method of the original disc of this invention, and a 4th process. It is a schematic diagram which shows the preparation method of the original disc of this invention, and a 5th process. It is a figure for demonstrating the production method of the original disk using a coupling prism. (A) It is a schematic diagram which shows the manufacturing apparatus which produces the original recording of this invention, (b) is a schematic diagram which shows the manufacturing apparatus after driving from the state shown to (a). It is a schematic diagram which shows the 2nd manufacturing apparatus for producing the original recording of this invention, (b) is a schematic diagram which shows the state driven from the state shown to (a). It is the schematic which shows the structure of an optical pick-up.

  The optical element according to the present invention will be described with respect to a hologram optical element master, a method for manufacturing the hologram optical element, and the like.

(Master of hologram optical element)
The master of the hologram optical element of the present invention will be described with reference to FIGS. FIG. 1A is a plan view showing an outline of a hologram optical element, and FIG. 1B is a side view of the hologram optical element.

  As shown in FIG. 1B, the hologram optical element 21 includes a hologram recording layer 23 and a substrate 24 disposed on both sides of the hologram recording layer 23 and sealing the hologram recording layer 23. The substrate 24 may be a transparent substrate such as glass or polycarbonate. Alternatively, one surface of the hologram recording layer 23 may be covered with a protective film. As shown in FIG. 1A, the hologram recording layer 23 is formed with an aggregate refractive index grating (aggregate diffraction pattern) 22. The collective refractive index grating 22 includes a plurality of refractive index gratings (diffraction patterns) 22b, 22c, 22d1, 22d2, 22e1, and 22e2. In the example shown in FIG. 1, the outer peripheral edge portion of the collective refractive index grating 22 is formed to be circular.

  When the 0th-order transmitted light 26 is perpendicularly incident on the hologram optical element 21, the 0th-order transmitted light 26 and the first-order diffracted lights 27b, 27c, and 27b are transmitted from the respective refractive index gratings 22b, 22c, 22d1, 22d2, 22e1, and 22e2. 27d1, 27d2, 27e1, 27e2 are emitted.

  The zero-order transmitted light 26 is collected at the focal point 28a. The first-order diffracted light 27b is collected at the focal point 28b, and the first-order diffracted light 27c is collected at the focal point 28c. The first-order diffracted lights 27d1 and 27d2 are condensed on the focal point 28d, and the first-order diffracted lights 27e1 and 27e2 are condensed on the focal point 28e. In the example shown in FIGS. 1A and 1B, light receiving elements 20a to 20e are disposed at the respective focal points 28a to 28e. The focal points 28 a to 28 e are arranged on the virtual plane so that the light receiving elements 20 a to 20 e can be arranged on a virtual plane parallel to the hologram recording layer 23.

  FIG. 2A is a plan view schematically showing a master 32 used when manufacturing the hologram optical element, and FIG. 2B is a side view of the master 32 of the hologram optical element. 3 is a side view showing a relative positional relationship with a hologram optical element 21. FIG. The master 32 shown in FIG. 2A is a master for recording the collective refractive index grating 22 of the hologram optical element 21 shown in FIG. 1A, and irradiates the master 32 with a light beam equivalent to the reproduction light. Thus, each refractive index grating of the collective refractive index grating 22 is recorded by two-beam interference. As shown in FIG. 2, the master 32 includes a hologram recording layer 33 and a substrate 34 that seals the hologram recording layer 33. The substrate 34 may be a transparent substrate such as glass or polycarbonate. Or you may make it cover the single side | surface of the hologram recording layer 33 with the protective film which protects.

  As shown in FIG. 2A, the hologram recording layer 33 is formed with a collective refractive index grating (aggregate diffraction pattern) 30, and the collective refractive index grating 30 includes a plurality of refractive index gratings (diffraction patterns). 30a, 30b, 30c, 30d1, 30d2, 30e1, and 30e2 are formed. The reproduction light 35 is incident on the refractive index gratings 30 a, 30 b, 30 c, 30 d 1, 30 d 2, 30 e 1, and 30 e 2 of the master disk 32 from one main surface of the master disk 32 by causing the reproduction light 35 that is a plane wave from a specific direction. Diffraction is performed by the refractive index gratings 30a, 30b, 30c, 30d1, 30d2, 30e1, and 30e2. Then, the first-order diffracted lights 36 a, 36 b, 36 c, 36 d 1, 36 d 2, 36 e 1, 36 e 2 are emitted from the other main surface of the master 32.

  The refractive index gratings 30a, 30b, 30c, 30d1, 30d2, 30e1, and 30e2 are changed from the focal points 28a to 28e in FIG. 1 to the zero-order transmitted light 26 and the first-order diffracted lights 27b, 27c, and 27d1, corresponding to the focal points 28a to 28e. Each virtual light obtained by extending the zero-order transmitted light 26 and the first-order diffracted lights 27b, 27c, 27d1, 27d2, 27e1, 27e2 in the direction opposite to the traveling direction of 27d2, 27e1, 27e2, and the hologram recording shown in FIG. It is formed at a position where the layer 33 intersects. A part of the refractive index grating 30a, a part of the refractive index grating 30b, and a part of the refractive index grating 30d2 overlap each other.

  In FIG. 2B, the focal points 37a to 37e coincide with the focal points 28a to 28e in FIG. The 0th-order transmitted light 26 and the refractive index gratings 22b, 22c, 22d1, 22d2, 22e1, and 22e2 shown in FIG. 1B are converted into the first-order diffracted lights 36a, 36b, 36c, and 36d1, shown in FIG. It overlaps with 36d2, 36e1, and 36e2.

  Refractive index gratings 30a, 30b, 30c, 30d1, 30d2, 30e1, and 30e2 are two light fluxes equivalent to the reproduction light 35 and light fluxes equivalent to the first-order diffracted light 36a, 36b, 36c, 36d1, 36d2, 36e1, and 36e2. Recorded by beam interference.

  Furthermore, although details will be described later, in FIGS. 1A and 2B, the collective refractive index grating 22 is positioned at a position where the first-order diffracted light 36a from the refractive index grating (first diffraction pattern) 30a passes. When the hologram recording layer 23 is arranged, the refractive index grating (first diffraction pattern) 22b shown in FIG. 1 (a) has the first-order diffracted light 36b from the refractive index grating 30b shown in FIG. 2 (a) and the refractive index grating 30a. Is formed in a region where the first-order diffracted light 36a from the light beam intersects.

  The refractive index grating 22c shown in FIG. 1A is formed in a region where the first order diffracted light 36c from the refractive index grating 30c shown in FIG. 2A intersects with the first order diffracted light 36a from the refractive index grating 30a. . The refractive index grating 22d1 shown in FIG. 1A is formed in a region where the first order diffracted light 36a shown in FIG. 2A intersects with the first order diffracted light 36d1 from the refractive index grating 30d1. The refractive index grating 22d2 shown in FIG. 1A is formed in a region where the first order diffracted light 36a shown in FIG. 2A intersects with the first order diffracted light 36d2 from the refractive index grating (third diffraction pattern) 30d2. The The refractive index grating 22e1 shown in FIG. 1A is formed in a region where the first order diffracted light 36a shown in FIG. 2A intersects with the first order diffracted light 36e1 from the refractive index grating 30e1. The refractive index grating 22e2 shown in FIG. 1A is formed in a region where the first order diffracted light 36a shown in FIG. 2A intersects the first order diffracted light 36e2 from the refractive index grating 30e1.

  Note that the collective refractive index grating 22 of the hologram optical element 21 can be appropriately changed by appropriately changing the refractive index grating shown in FIG.

(Method for manufacturing hologram optical element using master)
A method for replicating a hologram optical element using the master disk of the present invention will be described with reference to FIGS. FIG. 3 is a schematic diagram showing a method for manufacturing a hologram optical element. In the hologram optical element manufacturing method shown in FIGS. 3 to 5, for the sake of easy understanding, description is given focusing on the refractive index gratings 30 a and 30 b of the collective refractive index grating 30. 3 shows only the first-order diffracted light 36a and the first-order diffracted light 36b extracted from the diffracted light beam emitted from the master disk 32 in FIG.

  First, the master disk 32 is prepared. The master disc 32 includes a hologram recording layer 33 including two main surfaces arranged in the thickness direction, and a substrate 34 disposed on each main surface of the hologram recording layer 33. Then, the duplication recording element 45 is arranged at a predetermined interval from the master disk 32. As a matter of course, after the duplication recording element 45 is arranged, the master 32 may be arranged at a distance from the duplication recording element 45. The duplication recording element 45 includes a substrate 43 having two main surfaces facing each other in the thickness direction, and a hologram recording layer 46 formed on the main surface facing the master 32 out of the main surfaces of the substrate 43.

  Then, the reproduction light 35, which is a plane wave, is incident on the master disk 32 from a specific direction. Refractive index gratings 30a and 30b are recorded on the hologram recording layer 33 of the master 32, and the focused light is diffracted, and the first-order diffracted lights 36a and 36b are emitted from the refractive index gratings 30a and 30b.

  The first-order diffracted light 36a is a light flux equivalent to the 0th-order transmitted light that passes through the hologram optical element in the optical pickup, and the first-order diffracted light 36b is a light flux equivalent to the first-order diffracted light incident on the light receiving element 20b in the optical pickup. It is. The first-order diffracted light 36 a includes a light beam that travels perpendicular to the main surface of the hologram recording layer 33 that faces the duplication recording element 45.

  The first-order diffracted light 36 b includes a light beam traveling in a direction inclined with respect to the main surface of the hologram recording layer 33 facing the duplication recording element 45.

  At least a part of the first-order diffracted light 36b and at least a part of the first-order diffracted light 36b cross each other and interfere with each other.

  The refractive index grating 22b is recorded on the hologram recording layer 46 by arranging the hologram recording layer 46 in an area where the first-order diffracted beams 36a and 36b interfere. In other words, the region located between the refractive index grating 30a and the focal point 37a and the region through which the first-order diffracted light 36a passes and the region located between the refractive index grating 30b and the focal point 37b and through which the first-order diffracted light 36b pass are overlapped. A refractive index grating 22b is formed in a portion where each region overlaps. The focal point 37b and the focal point 37b are located on the virtual plane S. The virtual plane S is parallel to the main surface located on the duplication recording element 45 side in the main surface of the hologram recording layer 33.

  A transparent substrate such as glass or polycarbonate may be provided on the surface of the duplication recording element 45 on the master 32 side, and the hologram recording layer 46 may be covered with a protective film. Furthermore, a state where the release agent when the hologram recording layer 46 is shaped is applied to the surface of the duplication recording element 45 on the master 32 side may be used. The reproduction light 35 is diffracted and then reflected by the reflecting surface 49. Thereby, since the reproduction light 35 does not enter the recording element 45 for duplication, unnecessary exposure can be prevented.

  In FIG. 3, the master 32 is simplified, and the first-order diffracted light 36a from the refractive index grating 30a and the first-order diffracted light 36b from the refractive index grating 30b are shown to completely overlap. This is shown for easy understanding, and the first-order diffracted light 36b intersects a part of the first-order diffracted light 36a.

  As shown in FIGS. 2A and 2B, the hologram recording layer 33 is formed with a plurality of refractive index gratings 30c to 30e2 in addition to the refractive index grating 30b. As shown in FIGS. 2A and 2B, the first-order diffracted light 36c from the refractive index grating 30c and a part of the refractive index grating 30a intersect each other. The hologram recording layer 46 shown in FIG. 3 is located in a region where the first-order diffracted light 36c and a part of the refractive index grating 30a intersect. A refractive index grating 22c shown in FIG. 1A is formed on the hologram recording layer 46 by interference fringes formed by a part of the first-order diffracted light 36a and the first-order diffracted light 36c.

  Similarly, a part of the first-order diffracted light 36a from the refractive index grating 30a shown in FIGS. 2A and 2B intersects with the first-order diffracted lights 36d1 and 36d2 from the refractive index gratings 30d1 and 30d2. The hologram recording layer 46 shown in FIG. 3 is located at a portion where a part of the first-order diffracted light 36a and the first-order diffracted lights 36d1 and 36d2 intersect. The refractive index gratings 22d1 and 22d2 shown in FIG. 1 are formed by interference fringes between a part of the first-order diffracted light 36a and the first-order diffracted lights 36d1 and 36d2.

Similarly, a part of the first-order diffracted light 36a from the refractive index grating 30a shown in FIGS. 2A and 2B intersects with the first-order diffracted lights 36e1 and 36e2 from the refractive index gratings 30e1 and 30e2. The hologram recording layer 46 shown in FIG. 3 is located at a portion where a part of the first-order diffracted light 36a1 and the first-order diffracted lights 36e1 and 36e2 intersect. The refractive index gratings 22e1 and 22e2 shown in FIG. 1 are formed in the hologram recording layer 46 by a part of the first-order diffracted light 36a and interference fringes between the first-order diffracted lights 36e1 and 36e2.

  As described above, the first-order diffracted light 36c, 36d1, 36d2, 36e1, and 36e2 among the light beams diffracted from the master disk 32 of FIG. Refractive index gratings 30c, 30d1, 30d2, 30e1, and 30e2 are recorded by interfering with the first-order diffracted light 36a. As a result, the collective refractive index grating 22 shown in FIG. 1A is formed in the hologram recording layer 46. That is, the master 32 functions as a mask that generates the total luminous flux necessary for producing the hologram optical element by entering the reproduction light 35 and reflects the unnecessary luminous flux. At this time, the incident angle of the reproduction light 35 with respect to the master 32 is larger than the maximum value of the diffraction angle with respect to the master 32 of the first-order diffracted light 36b and a light beam equivalent to the first-order diffracted light 36c to e shown in FIG. Larger is preferred. More preferably, the incident angle of the reproduction light 35 with respect to the master disk 32 is the total reflection angle of the reflection surface 49.

  FIG. 4 is a schematic diagram showing a manufacturing method for manufacturing a large number of hologram optical elements. In FIG. 4, in order to make the explanation easy to understand, the refractive index gratings 30 a and 30 b of the collective refractive index grating 30 are described with focus on the other refractive index gratings 30 c, 30 d 1, 30 d 2, and 30 e 1. , 30e2 are not shown. A master 51 shown in FIG. 4 is a master of a hologram optical element used when manufacturing a plurality of hologram optical elements 21 at the same time.

  The master 51 includes a substrate 52, a hologram recording layer 53 formed on the main surface of the substrate 52, and a substrate 54 disposed on the hologram recording layer 53. In the hologram recording layer 53, a plurality of collective index gratings 30 are formed. In FIG. 4, a plurality of refractive index gratings 30 a and 30 b that are equal to each other are recorded on the same surface on the master disk 51. Although not shown in FIG. 4, a plurality of other refractive index gratings 30c, 30d1, 30d2, 30e1, and 30e2 are also formed. The master 51 and the duplication recording element 55 are arranged with a space therebetween. The duplication recording element 55 includes a substrate 58 and a hologram recording layer 56 formed on the main surface of the substrate 58.

  Then, the reproduction light 35 that is a plane wave is incident on the master 51 from a specific direction. By the incidence of the reproduction light 35, a plurality of first-order diffracted light 36a and a plurality of diffracted light 36b, which are a plurality of focused lights that are equal to each other, are generated. By disposing the duplication recording element 55 that records the interference fringes in the region where the diffracted light 36a and 36b interfere, a plurality of equal interference fringes 57 can be recorded on the hologram recording layer 56 at a time, and a plurality of refractions can be recorded. A rate grating 22b is formed. The hologram recording layer 56 may be applied in the form of dots at positions where the refractive index grating (interference fringes 57) is recorded.

  Similarly, the first-order diffracted light 36c, 36d1, 36d2, 36e1, 36e2 from the refractive index gratings 30c, 30d1, 30d2, 30e1, 30e2 of the collective refractive index grating 30 (not shown) and the first-order diffracted light 36a of the refractive index grating 30a Interference fringes are recorded on the hologram recording layer 56. Further, a plurality of refractive index gratings are formed by the first-order diffracted light 36a from the plurality of refractive index gratings 30a. As a result, the collective refractive index grating 22 is formed in the hologram recording layer 56.

  FIG. 5 is a schematic view showing a hologram optical element manufacturing apparatus. Laser light oscillated from a light source 60 that emits laser light is collimated by a spatial filter and a collimator lens (not shown), and guided to an expander lens 62 by a mirror 61. The light passes through the aperture 63 and the coupling prism 64 and enters the master 51. When the reproduction light is incident on the master 51, a plurality of first-order diffracted light is diffracted as described above, and interference fringes due to the diffracted light are recorded as a refractive index grating on the hologram recording layer. Note that the coupling prism 64 may be omitted.

  When the hologram recording layer is subjected to two-beam interference exposure, oxygen contained in the recording layer hinders the photopolymerization reaction, so that an area where the hologram optical element records incoherent light such as an LED before exposure. Irradiate temporarily. The laser beam used for recording may be separated by a coherent length or longer to irradiate the recorded area. However, when the same light source is used, it is necessary to pass through a plurality of mirrors in order to make the optical path length longer than the coherent length. Therefore, it is preferable to use a separate light source. Further, after the duplication recording layer is subjected to two-beam interference exposure, the incoherent light is similarly irradiated in order to suppress further reaction. With this irradiation, the recorded interference fringes can be fixed. Although the light source for generating the incoherent light is not shown in FIG. 5, for example, it is disposed immediately before the surface of the duplication recording element 55 that is not substantially in close contact with the master 51, and when performing two-beam interference exposure, It is good to drive so that it can be retracted so as not to be disposed in the area. Further, for example, a light source that generates the incoherent light is disposed at a position that does not interfere with the diffracted light, and is substantially the same as the master 51 of the recording element 55 for duplication via a mirror disposed at a position that does not interfere with the diffracted light. The area to be recorded may be irradiated from a surface that does not adhere.

(Preparation method of master)
A method for manufacturing a master according to the present invention will be described with reference to FIGS. FIG. 6A is a side view schematically showing a first step of a method for producing a master, and FIG. 6B is a plan view schematically showing a first step of the method for producing a master.

  First, the first refractive index grating 30 a is recorded on the hologram recording layer 75 of the master recording element 74 by two-beam interference exposure of the first recording light 72 a and the reference light 73. The first recording light 72 a is generated by transmitting laser light through the sector mask 70 a and the objective lens 71. Here, the first recording light 72a is a light beam equivalent to the first-order diffracted light 36a in FIG. 3 (the zero-order transmitted light 26 shown in FIG. 2B). Similarly to the first-order diffracted light 36a, the first recording light 72a is condensed at the focal point 78a.

  The hologram recording layer 75 is formed in a flat plate shape on the main surface of the substrate 76, the first main surface irradiated with the first recording light 72a, and the second main surface located on the opposite side of the first main surface. Including a surface.

  The first main surface of the hologram recording layer 75 is disposed so as to be perpendicular to the optical axis of the first recording light 72a. The reference light 73 is parallel light incident on the master at the same incident angle as the reproduction light used for replicating the hologram optical element. In the hologram recording layer 75, the surface on which the two light beams are incident may be a transparent substrate such as glass or polycarbonate, may be covered with a protective film that protects the hologram recording layer 75, and the hologram recording layer. A state in which a release agent when 75 is shaped may be applied.

FIGS. 7A to 7E are plan views showing sector masks. The sector mask 70a shown in FIG. 7A is a mask used when forming the refractive index grating 30a. The sector mask 70a is formed with a circular hole through which the first recording light 72a passes. ing.

  FIG. 8A is a side view schematically showing a second step of the master production method, and FIG. 8B is a plan view schematically showing a second step of the master production method. FIG. 8B is a plan view of the master recording element 74 viewed from the optical axis direction of the second recording light 72c. The second refractive index grating 30 c is recorded on the hologram recording layer 75 of the master recording element 74 by the two-beam interference exposure of the second recording light 72 c and the reference light 73. The second recording light 72c is generated by transmitting the laser light through the sector mask 70c and the objective lens 71. The second recording light 72c is a light beam equivalent to the diffracted light 36c in FIG. The second recording light 72c is also collected at the focal point 78c.

  Here, the master recording element 74 shown in FIG. 8A is rotated from the state shown in FIG. 6A around a virtual axis perpendicular to the paper surface, and shifted so as to be close to the objective lens 71. I am letting.

  A focal point 78 a 1 in FIG. 8A is a position when the focal point 78 a shown in FIG. 6A is rotated and shifted in the same manner as the original recording element 74, similarly to the original recording element 74.

  The focal points 78a1 and 78c are arranged on a virtual plane S parallel to the main surface of the hologram recording layer 75. The relative positional relationship between the focal points 78a1 and 78c coincides with the relative positional relationship between the light receiving elements 20a and 20c shown in FIG.

  The reference light 73 is parallel light incident on the hologram recording layer 75 at the same incident angle as in the first step. That is, the reference light 73 is shifted, tilted, and rotated by the same amount as the master recording element 74 is shifted, tilted, and rotated so that the reference light 73 enters the main surface of the hologram recording layer 75 in the same direction. ing. For this reason, in any state shown in FIG. 6A and FIG. 7A, the incident angles at which the reference light 73 enters the hologram recording layer 75 are the same. Further, when the hologram recording layer 75 is viewed from a direction perpendicular to the main surface of the hologram recording layer 75, the planar direction in which the reference light 73 is incident on the reference light 73 also coincides.

  That is, when the hologram recording layer 75 is used as a reference, the reference light 73 is always incident on the hologram recording layer 75 from the same incident angle and direction. 8A. As shown in FIG. 7C, the sector mask 70c shown in FIG. 8A has a hole corresponding to a part of the opening of the sector mask 70a.

  FIG. 9A is a side view schematically showing a third step of the method for producing the master, and FIG. 9B is a plan view schematically showing the third step of the method for producing the master. FIG. 9B is a plan view of the master recording element 74 as seen from the optical axis direction of the third recording light 72b. By the two-beam interference exposure of the third recording light 72 b and the reference light 73, the third refractive index grating 30 b is recorded on the hologram recording layer 75 of the master recording element 74. The third recording light 72 b is generated by transmitting the laser light through the sector mask 70 b and the objective lens 71. Here, the third recording light 72b is a light beam equivalent to the diffracted light 36b in FIG. 3, and the third recording light 72b is collected at the focal point 78b. As shown in FIG. 7B, the sector mask 70b has a hole corresponding to a part of the hole formed in the sector mask 70a. The third recording light 72b passes through a hole formed in the sector mask 70b.

  When forming the refractive index grating 30b as shown in FIG. 9, the master recording element 74 is moved from the state shown in FIG. The focal points 78a2 and 78c1 shown in FIG. 9A are virtual points when the focal points 78a1 and 78c shown in FIG. 8A are moved along with the movement of the recording element 74 for master. The relative positional relationship between the focal points 78b, 78a2, and 78c1 is the relative positional relationship between the focal points 28b, 28a, and 28c shown in FIG.

  That is, the master recording element 74 is moved from the state shown in FIG. 8 so that the distance between the focal points 78b, 78a2, and 78c1 is the distance between the light receiving elements 20b, 20a, and 20c.

  The reference light 73 is parallel light incident on the hologram recording layer 75 at the same incident angle as in the first step. That is, the reference beam 73 is shifted, tilted, and rotated by the same amount as the master recording element 74 is shifted, tilted, and rotated so that the reference beam 73 is incident on the hologram recording layer 75 in the same direction. .

  FIG. 10A is a side view schematically showing the fourth step of the master production method, and FIG. 10B is a plan view showing the fourth step of the master production method. Next, the fourth refractive index grating 30d (30d1, 30d2) is recorded in the hologram recording layer 75 of the master recording element 74 by two-beam interference exposure of the fourth recording light 72d and the reference light 73. The fourth recording light 72d is generated by transmitting laser light through the sector mask 70d and the objective lens 71. As shown in FIG. 7D, the sector mask 70d has a hole corresponding to a part of the hole formed in the sector mask 70a. The fourth recording light 72d passes through a hole formed in the sector mask 70a. Here, the fourth recording light 72d is a light beam equivalent to the diffracted light 36d in FIG. The focal point 78d of the recording light 72d is located on the virtual plane S parallel to the surface of the hologram recording layer 75.

  Here, the focal point 78a3 shown in FIG. 10A is a virtual point when the focal point 78a2 shown in FIG. 9A is moved along with the movement of the master recording element 74. The relative position relationship between the focal point 78a3 and the focal point 78d is such that the master recording element 74 moves so that the relative position between the light receiving element 20a and the light receiving element 20d shown in FIG. Yes.

  That is, the master recording element 74 is moved from the state of the first step so that the distance between the focal point 78d and the focal point 78a3 coincides with the distance between the light receiving element 20a and the light receiving element 20d shown in FIG. Shift, tilt and rotate. The reference light 73 is parallel light that is incident on the hologram recording layer 75 in the same incident direction as in the first step. That is, the reference light 73 is shifted, tilted, and rotated by the same amount as the master recording element 74 is shifted, tilted, and rotated so that the reference light 73 enters the main surface of the hologram recording layer 75 in the same direction. ing.

  FIG. 11A is a side view schematically showing the fifth step of the method for producing the master, and FIG. 11B is a side view schematically showing the fifth step of the method for producing the master. By the two-beam interference exposure of the fifth recording light 72e and the reference light 73, the fifth refractive index grating 30e (30e1, 30e2) is recorded on the hologram recording layer 75 of the master recording element 74. The fifth recording light 72e is generated by transmitting the laser light through the sector mask 70e and the objective lens 71. As shown in FIG. 7E, the sector mask 70e has a hole corresponding to a part of the hole formed in the sector mask 70a. In FIGS. 11A and 11B, the fifth recording light 72e is a light beam equivalent to the diffracted light 36e in FIG. The recording light 72e passes through the condensing position of the recording light 72a and is condensed at a focal point 78e on the virtual plane S parallel to the main surface of the hologram recording layer 75.

  In FIG. 11A, a focal point 78a4 is a virtual point when the focal point 78a3 shown in FIG. 10A is moved along with the movement of the master recording element 74.

  The relative positional relationship between the focal point 78e and the focal point 78a coincides with the relative positional relationship between the light receiving element 20e and the light receiving element 20a shown in FIG.

  That is, the master recording element 74 is shifted from the state of the first step so that the distance between the focus 78a4 and the focus 78e is equal to the distance between the light receiving element 20a and the light receiving element 20e shown in FIG. It is tilted and rotated. The reference light 73 is parallel light incident on the hologram recording layer 75 at the same incident angle as in the first step. That is, the reference beam 73 is shifted, tilted, and rotated by the same amount as the master recording element 74 is shifted, tilted, and rotated so that the reference beam 73 is incident on the hologram recording layer 75 in the same direction. .

  The diffraction grating is manufactured through the above steps. From the first step to the fifth step, the order may be random. 6 to 11, the sector mask 70 is disposed immediately before the objective lens 71, but may be immediately after the objective lens 71 and immediately before the recording element 74 for master. Although the objective lenses are all equal, the objective lens 71 that records the recording light 72a and the objective lens 71 that records the recording lights 72b to 72e may be different. Further, each sector mask shown in FIGS. 7A to 7E is obtained by cutting out a first-order diffracted light component to be guided to each light-receiving element in the optical pickup. In the first step, the zero-order transmission is performed. It is not necessary to use a mask notched in a circular shape as with light, or to use a sector mask. Of course, the hologram optical element capable of diffracting a diffracted light beam in five or more directions and the hologram optical element capable of diffracting a diffracted light beam in three or less directions can be manufactured by the same method.

  Since oxygen contained in the recording layer hinders the photopolymerization reaction, incoherent light such as an LED is temporarily irradiated onto the area where the refractive index grating is recorded before exposure. In addition, after the two-beam interference exposure of the refractive index grating, the incoherent light is similarly irradiated in order to suppress further reaction. By this irradiation, the recorded refractive index grating can be fixed. When manufacturing the hologram optical element, it is necessary to provide the reflection surface 49 (see FIG. 3) described above. For this reason, after the two-beam interference exposure in the production of the master, a process of forming a reflecting surface on the substrate is performed. In addition, the board | substrate 76 (refer FIG. 6) in which the said reflective surface was formed corresponds to the board | substrate 42 of FIG.

  The reflection surface 49 is generated by performing a coating process on the surface on which the reflection surface is formed after the exposure process of the hologram recording layer 75. Alternatively, a reflection plate having a high reflectance with respect to a specific incident angle is separately prepared, and the reflection surface of the reflection plate is set as the reflection surface 49 by being overlaid on the hologram recording layer 75 after the exposure process. In the method using the reflecting plate, the same effect can be obtained by inserting the reflecting plate between the substrate and the hologram recording layer 75 without overlapping the reflecting plate on the hologram recording layer 75.

  FIG. 12 is a diagram for explaining a method of manufacturing a master using a coupling prism. Referring to FIG. 12, the method using coupling prism 93 is performed when the incident angle of reference light 73 originally corresponds to the reflection angle of substrate 76 and when the reflection surface is provided on lower surface 76 a of substrate 76. Limited. The reflection surface is strongly reflected at a specific incident angle (outgoing angle). Therefore, as shown in FIG. 12, when the coupling prism 94 is brought into close contact in the exposure process of the hologram recording layer (recording material for master disc) 75, the incident surface and the exit surface of the coupling prism 94 deviate from the specific angle. For this reason, the reference beam 73 can be transmitted.

(Equipment for making the master)
An apparatus for producing the master of the present invention will be described with reference to FIGS. 13 (a) and 13 (b) and FIGS. 14 (a) and 14 (b). FIG. 13A is a schematic diagram of a manufacturing apparatus for producing the master disk of the present invention. The master production apparatus is configured as follows, for example.

  The master manufacturing apparatus includes a light source 80 that emits laser light, a beam splitter 81 that branches the laser light from the light source 80 into laser light L1 and laser light L2, and condenses the laser light L1. An objective lens 87 for recording light L3 is provided. Further, the master production apparatus holds the reflection device 88 that reflects the laser light L2 and the master recording material 90 so that the recording light L3 and the laser light L2 intersect, and the recording light L3 and the laser light L2. Includes a master recording material 90 that holds the master recording material 90 so as to intersect with the master recording material 90. The master production apparatus further includes a control unit 92 that controls the driving of the reflection device 88 and a mirror 89 that reflects the laser light L1 branched from the beam splitter 81 toward the objective lens 87. The reflection device 88 includes a movable mirror 83, a mirror 82, a parabolic mirror 85, a rotating mirror 84, a sector mask 86, and an objective lens 87.

  The light source 80 emits laser light (light beam). The mirror 89 reflects the laser light L 1 branched by the beam splitter 81 toward the sector mask 86 and the objective lens 87. The objective lens 87 condenses the laser light L1 reflected by the mirror 89 to obtain recording light L3. The holder 93 supports the recording material 90 for master, and the holder 93 is provided so as to be movable in the direction close to and away from the objective lens 87 shown in FIG. The rotation center line is provided so as to be rotatable, and the rotation center line is provided so as to be inclined. The master recording material 90 is a photosensitive material. The rotation center line of the holder 93 is parallel to the optical axis of the recording light L3 in the initial state. The holder 93 adjusts the inclination angle of the recording material 90 for master with respect to the recording light L3 by inclining so that the rotation center line of the holder 93 is inclined with respect to the recording light L3. The holder 93 can change the position of the recording light L3 irradiated to the master recording material 90 by rotating.

  The laser light oscillated from the light source 80 branches into a laser light L1 that passes through the beam splitter 81 and a laser light L2 that is reflected by the beam splitter 81. In the example shown in FIG. 13A, the beam splitter 81 splits the light beam from the light source 80 into a laser beam L1 and a laser beam L2 that travels in a traveling direction perpendicular to the traveling direction of the laser beam L1. However, the branching angles of the laser light L1 and the laser light L2 are set as appropriate.

  The movable mirror 83 is provided so as to be movable between a position where the laser beam L2 branched by the beam splitter 81 is reflected and a position away from the laser beam L2 branched from the beam splitter 81. The mirror 82 is provided at a position where the laser beam L2 can be reflected when the movable mirror 83 is retracted from the position where the laser beam L2 is reflected.

  The rotating mirror 84 is provided at a position away from the laser beam L2 reflected by the movable mirror 83, and the rotating mirror 84 reflects the laser beam L2 reflected by the mirror 82 toward the parabolic mirror 85. Has been placed.

  The rotating mirror 84 has a reflecting surface that is rotatable, and can adjust the reflection angle of the laser light L2. Thereby, the incident direction of the laser beam L2 incident on the parabolic mirror 85 can be adjusted, and the reflection direction of the laser beam L2 reflected by the parabolic mirror 85 can be adjusted as appropriate.

  The state shown in FIG. 13A shows the state corresponding to the manufacturing process shown in FIGS. 6A and 6B, and the recording light L3 corresponds to the first recording light 72a in FIG. .

  A plurality of sector masks 86 are prepared in advance, and can be appropriately replaced in accordance with interference fringes (refractive index grating) formed on the master recording material 90. The objective lens 87 is a condensing lens that condenses the laser light L1. Note that the focal point of the recording light L3 is located on the opposite side of the objective lens 87 with respect to the master recording material 90.

  In the state shown in FIG. 13A, the movable mirror 83 reflects the laser beam L2, and the laser beam L2 reflected by the movable mirror 83 is incident on the main surface of the master recording material 90 from a specific fixed direction. . Specifically, when the main surface of the master recording material 90 is viewed from a direction perpendicular to the main surface of the master recording material 90, the laser beam L2 is recorded on the master recording material 90 as a reference. The direction of the plane direction entering the material 90 is determined in advance, and the incident angle at which the laser beam L2 is incident on the master recording material 90 is also determined in advance. In FIG. 6A, the recording light L3 corresponds to the first recording light 72a, and the laser light L2 corresponds to the reference light 73. Interference fringes (refractive index grating) are recorded on the master recording material 90 by causing the recording light L3 and the laser light L2 to interfere with each other.

  Thus, after forming the refractive index grating 30a, when the refractive index grating 30b and the like are further formed on the recording material 90 for master, as shown in FIG. Any one of a direction to shift toward the objective lens 87, a direction to rotate around a virtual axis parallel to the Z-axis, and a direction to incline so that the rotation center line of the holder 93 intersects the optical axis of the recording light L3 Move in the direction by a preset amount of movement. Further, the control unit 92 retracts the movable mirror 83 away from the optical axis of the laser beam L2, and the control unit 92 replaces the sector mask 86. A specific example of the sector mask 86 is shown in FIG. 7, for example. Then, the mirror 82 reflects the laser beam L2 toward the rotating mirror 84. The posture of the rotating mirror 84 is a predetermined posture based on a command from the parabolic mirror 85.

  The laser beam L2 reflected by the rotating mirror 84 is reflected by the parabolic mirror 85 and is incident on the master recording material 90.

  Here, as shown in FIGS. 13A and 13B, the incident direction when the laser beam L2 reflected by the movable mirror 83 enters the recording material 90 for master and the laser beam reflected by the parabolic mirror 85. The incident direction when L2 enters the master recording material 90 coincides with the incident direction. That is, the incident angle when the laser beam L2 reflected by the parabolic mirror 85 is incident on the master recording material 90 is a predetermined specific incident angle, and is perpendicular to the main surface of the master recording material 90. The plane direction in which the laser beam L2 enters the master recording material 90 when the main surface is viewed from any direction is also a predetermined direction. Specifically, as the recording material 90 for master is rotated, the rotating mirror 84 also follows and rotates. Thus, the laser beam L2 from the parabolic mirror is always at the same position on the main surface of the master recording material 90, at the same incident angle, and at the same angle in the rotation direction (θ direction) of the master recording material 90. Then, the light enters the master recording material 90. That is, with reference to the master recording material 90, the laser light L2 is always incident from the same direction toward the same position.

  The laser beam L1 shown in FIG. 13B corresponds to the second recording beam 72b shown in FIG. 8A, and the laser beam L2 corresponds to the reference beam 73. Then, interference fringes (refractive index grating) are formed on the master recording material 90 by causing the recording light L3 and the laser light L2 to interfere with each other.

  Further, when forming a plurality of types of interference fringes on the master recording material 90, the control unit 92 moves the rotating mirror 84 and the holder 93.

  Specifically, as the recording material 90 for master is rotated, the rotating mirror 84 also follows and rotates. Thus, the laser beam L2 from the parabolic mirror is always at the same position on the main surface of the master recording material 90, at the same incident angle, and at the same angle in the rotation direction (θ direction) of the master recording material 90. Then, the light enters the master recording material 90.

  Then, the recording light L3 and the laser light L2 form a new interference fringe (refractive index grating) on the recording material 90 for master. In this way, a plurality of refractive index gratings are formed on the master recording material 90.

  For example, as shown in FIGS. 9A and 9B, the refractive index grating 30c is formed on the recording material 90 for master. Similarly, after forming the refractive index grating 30c, the controller 92 moves the retainer 93 and the rotating mirror 84 to cause the laser light L1 and the laser light L2 to interfere on the recording material 90 for master, A refractive index grating 30d and a refractive index grating 30e are formed on the master recording material 90.

  14 (a) and 14 (b) are schematic views showing a modification of the apparatus for producing the master shown in FIGS. 13 (a) and 13 (b). 14A and 14B, a plurality of fixed mirrors 91 are employed in place of the parabolic mirror 85 shown in FIGS. 13A and 13B.

  The embodiment disclosed this time is an exemplification, and the present invention is not limited to the above contents. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied to a hologram optical element master manufacturing apparatus and master master manufacturing method.

  DESCRIPTION OF SYMBOLS 1 Optical disk, 2 Objective lens, 3 1/4 wavelength plate, 4 Sensor lens, 5 Beam splitter, 6 Diffraction optical element, 7 Light receiving element, 8 Diffraction grating, 9 Collimator lens 10, 11 Semiconductor laser, 12 Dichroic mirror, 20a ˜20e Light receiving element, 22b, 22c, 22d1, 22d2, 22e1, 22e2 Refractive index grating, 22 Collective index grating, 23 Hologram recording layer, 24 Substrate, 260th order transmitted light, 27b, 27c, 27d1, 27d2, 27e1, 27e2 First order diffracted light, 28a, 28b, 28c, 28d, 28e Focus, 30a, 30b, 30c, 30d1, 30d2, 30e1, 30e2 Refractive index grating, 30 Collective index grating, 32 Master, 33 Hologram recording layer, 34 Substrate, 35 Reproducing light, 36a, 36b, 36c, 3 d1, 36d2, 36e1, 36e2 First order diffracted light, 45 Replication recording element, 46, 53 Hologram recording layer, 49 Reflecting surface, 51 Master, 52 Substrate, 54 Substrate, 55 Replication recording element, 56 Hologram recording layer, 57 Interference Stripe, 58 substrate, 60 light source, 61 mirror, 62 expander lens, 63 aperture, 64 coupling prism, 70a, 70b, 70c, 70d, 70e sector mask, 71 objective lens, 72a, 72b, 72c, 72d, 72e Light, 73 reference light, 74 master recording element, 75 hologram recording layer, 80 light source, 81 beam splitter, 82 mirror, 83 movable mirror, 84 rotating mirror, 85 parabolic mirror, 86 sector mask, 87 objective lens, 90 master Recording material, 91 fixed mirror , 92 control unit, 93 retainer, L1 laser beam, L2 laser beam, L3 recording light, S imaginary plane.

Claims (5)

A master production apparatus for duplicating a hologram optical element,
A light source that emits a light beam;
A branching device that branches the light beam emitted from the light source into a first light beam and a second light beam that travels in a direction different from the traveling direction of the first light beam;
A lens that condenses the first light flux and serves as recording light;
A reflection device that reflects the second light beam and adjusts the reflection direction of the second light beam so that the recording light and the second light beam intersect;
A holder for holding the photosensitive material such that the recording light and the second light beam intersect in the photosensitive material;
A control unit for controlling the driving of the reflection device;
With
The holder holds the photosensitive material so that an inclination angle of the photosensitive material with respect to the recording light can be adjusted, and holds the photosensitive material rotatably.
The control unit drives the reflecting device in accordance with the tilt angle and the rotation of the photosensitive material so that the incident direction of the second light beam incident on the photosensitive material is a specific constant direction. apparatus. The reflection device is provided so as to be able to advance and retreat with respect to the second light beam emitted from the branching device, and is capable of reflecting the second light beam emitted from the branching device toward the photosensitive material, and A first reflection mirror provided so as to be movable between positions away from the second light beam; and a second reflection mirror that reflects the second light beam when the first reflection mirror is separated from the second light beam; A rotating reflecting mirror that includes a reflecting surface that reflects the second light beam reflected by the second reflecting mirror, the reflecting surface being rotatably provided, and the second light beam reflected by the rotating reflecting mirror. A third reflecting mirror that reflects toward the photosensitive material,
The incident direction of the second light flux reflected by the first reflecting mirror with respect to the photosensitive material is the specific constant direction,
Rotating the rotary reflecting mirror in accordance with the tilt angle and the rotation of the photosensitive material so that the incident direction of the second light beam reflected by the third reflecting mirror with respect to the photosensitive material is the specific constant direction; The master production apparatus according to claim 1.   3. The master production apparatus according to claim 1, wherein the holder moves so that a distance between the focal point of the recording light condensed by the lens and the photosensitive material is constant. A plurality of sector masks;
The sector mask is disposed in a path of the first light flux or the recording light,
Each sector mask is formed with a hole through which the first light beam or the recording light passes, and each hole has a different shape,
4. The master production apparatus according to claim 1, wherein the sector mask is replaced in accordance with the inclination angle and the rotation of the photosensitive material. A light source that emits a light beam, a branching device that branches the light beam emitted from the light source into a first light flux and a second light flux that travels in a direction intersecting the traveling direction of the first light flux, and the first light flux. The second light beam is reflected and the reflection direction of the second light beam can be adjusted so that the recording light and the recording light condensed by the lens intersect with the second light beam. A reflection device, a holding device for holding the photosensitive material, a holder for holding the photosensitive material so that the first light beam and the second light beam intersect at the photosensitive material, and a control for controlling the driving of the reflection device A step of preparing a master production apparatus comprising a portion;
Holding the photosensitive material in the holder;
Crossing the recording light and the second light flux reflected by the reflecting device at the photosensitive material to form interference fringes on the photosensitive material;
A method for manufacturing a master, comprising:

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