Hologram manufacturing apparatus, hologram manufacturing method, and light guide plate

Abstract

The present invention efficiently replicates a hologram having interference fringes similar to those of a plurality of master holograms. An apparatus for replicating interference fringes of master holograms 31 arranged in multiple rows and multiple columns to a photosensitive layer 11 includes: an exposure part C having a master layer 3 with the master holograms 31; a conveyance part B for placing the photosensitive layer 11 on a first surface side of the master layer 3; and a light source D for irradiating the master holograms 31 with coherent light L1. The conveyance part B places an elongated belt-shaped photosensitive layer 11 on the first surface side of the master layer 3, and then stops conveyance of the photosensitive layer 11. The light source D has a position changing mechanism part 63 for changing the irradiation position of the light L1 with respect to the master holograms 31, and the position changing mechanism part 63 changes the irradiation position to a first position for irradiating the plurality of master holograms 31 in one row with the light L1 and a second position for irradiating the plurality of master holograms 31 in another row with the light L1.

Description

Hologram manufacturing apparatus, hologram manufacturing method, and light guide plate

[0001] The present invention relates to a hologram manufacturing apparatus and method for manufacturing a hologram by replicating a master hologram.

[0002] A known method for manufacturing holograms involves optically replicating the interference fringes of a master hologram onto a photosensitive layer using a master hologram. Briefly, as shown in FIG. 22 , a laminate including a master layer containing a master hologram, an unexposed photosensitive layer in close contact with the master layer, and a glass plate in close contact with the photosensitive layer is irradiated with laser light from the glass plate side. The laser light passes through the glass plate and the photosensitive layer and is incident on the master hologram, generating diffracted light in the master hologram, which then passes through the photosensitive layer. The laser light and the diffracted light interfere with each other to expose the photosensitive layer, thereby recording the interference fringes of the master hologram in the photosensitive layer. In this way, the master hologram can be replicated onto the photosensitive layer. In other words, a hologram similar to the master hologram can be produced in the photosensitive layer.

[0003] For example, Patent Document 1 discloses a duplication method in which an original hologram is attached to a flat portion of a rotating body, a photosensitive film for duplication is wrapped around and tightly attached to the original hologram, the rotating body is intermittently rotated together with the photosensitive film for duplication, and when the rotating body comes to a standstill, reproduction light is irradiated at an angle to reproduce the original hologram, and the hologram information is intermittently reproduced on the photosensitive film for duplication.

[0004] Japanese Patent Application Publication No. 5-249876

[0005] The duplication method of Patent Document 1 involves rotating a rotor with a master hologram attached together with a photosensitive film, which can result in the formation of a gap between the master hologram and the photosensitive film. If a gap occurs between the two, the reconstructed light may be internally reflected at the air interface in the gap, or the refractive index of the reconstructed light may change. This can result in the inability to accurately duplicate the hologram information onto the duplication photosensitive film. Furthermore, Patent Document 1 does not disclose or suggest at all how to duplicate the interference fringes (information) of multiple master holograms onto a photosensitive layer, or how to irradiate the reconstructed light.

[0006] An object of the present invention is to provide a hologram manufacturing apparatus and method that efficiently irradiates a master layer having multiple columns and multiple rows of master holograms with coherent light to continuously produce holograms in a photosensitive layer.

[0007] In one aspect, a hologram manufacturing apparatus is provided, the hologram manufacturing apparatus of the first embodiment comprising: an exposure unit having a master layer having master holograms arranged in a plurality of columns in a width direction and a plurality of rows in a transport direction perpendicular to the width direction; a transport unit that transports an unexposed photosensitive layer and positions the photosensitive layer on a first surface side of the master layer in the exposure unit; and a light source that irradiates the master hologram with coherent light from the first surface side of the photosensitive layer, and exposes the master hologram by transmitting the coherent light and diffracted light generated from the master hologram by the irradiation of the coherent light through the photosensitive layer. In an apparatus for replicating interference fringes of a master hologram onto the photosensitive layer, the transport unit transports a long, strip-shaped photosensitive layer a predetermined length in the longitudinal direction and then stops transporting the photosensitive layer, and the light source has a position change mechanism that changes the irradiation position of coherent light onto the master hologram, and the position change mechanism changes the irradiation position between a first position where the coherent light is irradiated onto multiple master holograms extending in one row or one column, and a second position where the coherent light is irradiated onto multiple master holograms extending in another row or another column.

[0008] A second aspect of the hologram manufacturing apparatus is the first aspect, wherein the position changing mechanism does not operate until exposure of the photosensitive layer at the first position is complete. A third aspect of the hologram manufacturing apparatus is the first or second aspect, wherein the light source has a coherent light oscillator and a reflector that changes the direction of travel of the coherent light from the oscillator toward the master hologram, and the position changing mechanism moves the reflector to the first position and the second position. A fourth aspect of the hologram manufacturing apparatus is the third aspect, wherein a plurality of reflectors are provided corresponding to the plurality of master holograms arranged in the width direction. A fifth aspect of the hologram manufacturing apparatus is the third or fourth aspect, wherein the oscillator has a first oscillator that emits coherent light of a predetermined wavelength and a second oscillator that emits coherent light of a wavelength different from the wavelength of the coherent light of the first oscillator. A sixth form of hologram manufacturing apparatus is the manufacturing apparatus of any of the third to fifth forms, wherein the position change mechanism has a fixed unit, a moving unit, and a drive unit that moves the moving unit relative to the fixed unit along the transport direction of the photosensitive layer, and the reflector is provided on the moving unit.

[0009] A seventh embodiment of the hologram manufacturing apparatus is the manufacturing apparatus of any of the first to sixth embodiments, wherein the exposure unit further includes a light-transmitting plate arranged on the first surface side of the master layer, the transport unit transports the photosensitive layer between the first surface of the master layer in the exposure unit and the second surface of the light-transmitting plate, the light source irradiates the master hologram with coherent light from the first surface side of the light-transmitting plate, and a light-absorbing layer that absorbs the diffracted light is provided on the first surface of the light-transmitting plate in an area other than the area where the coherent light is incident on the master hologram. The eighth form of the hologram manufacturing apparatus is the manufacturing apparatus of any of the first to sixth forms, wherein the exposure unit further has a light-transmitting plate arranged on the first surface side of the master layer, the transport unit transports the photosensitive layer between the first surface of the master layer in the exposure unit and the second surface of the light-transmitting plate, the light source irradiates the master hologram with coherent light from the first surface side of the light-transmitting plate, and a light-absorbing layer that absorbs the diffracted light is provided on at least one of the end surfaces of the light-transmitting plate, the end surface on which the diffracted light travels.

[0010] In another aspect, a hologram manufacturing method of a ninth aspect is provided, comprising: a transport step of transporting an unexposed photosensitive layer to a first surface side of a master layer having master holograms arranged in a plurality of columns in a width direction and a plurality of rows in a transport direction perpendicular to the width direction; and an exposure step of irradiating the photosensitive layer with coherent light from the first surface side after arranging the photosensitive layer on the first surface side of the master layer, wherein the coherent light and diffracted light generated from the master hologram by the irradiation of the coherent light are transmitted through the photosensitive layer for exposure, thereby forming interference fringes of the master hologram on the photosensitive layer. a method for replicating a hologram on a layer, the photosensitive layer being in the form of a long strip, the transporting step transporting the long strip-shaped photosensitive layer a predetermined length in the longitudinal direction and then stopping the transport of the photosensitive layer, and the exposing step irradiating a plurality of master holograms extending in one row or one column with the coherent light to replicate interference fringes corresponding to the master holograms in that row or column in the photosensitive layer, and then irradiating a plurality of master holograms extending in another row or another column with the coherent light to replicate interference fringes corresponding to the master holograms in that row or column in the photosensitive layer. A tenth aspect of the present invention is the method for producing a hologram of the ninth aspect, wherein the coherent light is a red laser beam, a green laser beam, a blue laser beam, or a composite laser beam containing at least two laser beams selected from the group consisting of red laser beam, green laser beam, and blue laser beam.

[0011] According to the manufacturing apparatus and manufacturing method of the present invention, it is possible to efficiently replicate a hologram having interference fringes similar to those of a master hologram.

[0012] 1 is a side view of a hologram manufacturing apparatus according to a first embodiment; a plan view of an exposure unit of the manufacturing apparatus; a perspective view of the exposure unit and light source of the manufacturing apparatus; an enlarged cross-sectional view taken along line IV-IV in FIG. 2; a bottom view of the master layer, as viewed from the first surface side; a bottom view of a light-transmitting plate, as viewed from below; a perspective view of a first light-transmitting plate, as viewed from below; a reference side view of the exposure unit, illustrating one aspect in which reflected light of diffracted light is unlikely to enter a duplicate hologram; a reference side view of the exposure unit, illustrating another aspect in which reflected light of diffracted light is unlikely to enter a duplicate hologram; a reference view illustrating a method for producing a master hologram; a side view of a manufacturing apparatus for explaining the steps of a method for producing a hologram; a side view of a manufacturing apparatus for explaining the steps of the manufacturing method; a plan view of a duplicate hologram continuum in which holograms are continuously produced; a reference side view of a light guide plate on which a red duplicate hologram, a green duplicate hologram, and a blue duplicate hologram are stacked. 10A and 10B are perspective views of an exposure unit and a light source according to a second embodiment; a perspective view of a light source according to a third embodiment; a perspective view of a light source according to a fourth embodiment; a reference side view of an exposure unit according to a first example of a fifth embodiment; a reference side view of an exposure unit according to a second example of the fifth embodiment; a cross-sectional view of an exposure unit according to a sixth embodiment; (a) is a reference side view of an exposure unit according to a first example of a seventh embodiment, and (b) is a reference side view of an exposure unit according to a second example of the same; and (b) is a reference side view of an exposure unit according to a second example of the same. Reference views for explaining a conventional method of replicating a hologram.

[0013] [First Embodiment] One embodiment will be described below with reference to the drawings. In this specification, the "first surface" of a certain component (e.g., a master layer or a light-transmitting plate) refers to the surface on which coherent light is incident to expose a photosensitive layer, and the "second surface" of a certain component refers to the surface opposite to the first surface. Please note that the thickness, size, scale, and shape of components such as layers shown in each drawing may differ from the actual ones.

[0014] {Hologram manufacturing apparatus} Fig. 1 is a side view of a hologram manufacturing apparatus according to a first embodiment, Fig. 2 is a plan view of an exposure unit in the manufacturing apparatus as seen from above, Fig. 3 is a perspective view showing the exposure unit and light source in the manufacturing apparatus, and Fig. 4 is an enlarged cross-sectional view of the exposure unit cut along the transport direction. In Figs. 2 and 3, both sides of a long, strip-shaped material to be processed are omitted. Also, in Fig. 3, the master mounting member for mounting a master layer and the plate mounting member for mounting a light-transmitting plate are omitted. In this specification, the "transport direction" corresponds to the longitudinal direction of the material to be processed, and the "width direction" refers to the direction perpendicular to the longitudinal direction within the plane of the material to be processed.

[0015] A hologram manufacturing apparatus records interference fringes of the master hologram in a photosensitive layer by transmitting coherent light and diffracted light generated from a master hologram by irradiating the coherent light through the photosensitive layer, thereby replicating a hologram in the photosensitive layer. In this specification, a hologram replicated in a photosensitive layer may be referred to as a "replica hologram." The photosensitive layer used in the manufacturing apparatus is a long strip. By loading a long strip of photosensitive layer into the manufacturing apparatus and exposing the photosensitive layer using the manufacturing apparatus, multiple replicate holograms can be continuously obtained. The long strip is a strip whose longitudinal length is significantly longer than its lateral length. A long strip of photosensitive layer is typically stored wound on a roll and unwound from the roll when in use. A manufacturing apparatus for creating a replicate hologram in a long strip of photosensitive layer is specifically described below.

[0016] 1 to 4, manufacturing apparatus A has a conveying section B that conveys photosensitive layer 11 in the longitudinal direction, an exposure section C that exposes photosensitive layer 11 conveyed by conveying section B, and a light source D that irradiates coherent light L1 onto a stack including photosensitive layer 11 in exposure section C. Various operations of manufacturing apparatus A, which will be described later, are controlled by a control section (not shown) that includes a computer or the like. The general flow of manufacturing a duplicate hologram is to convey photosensitive layer 11 to exposure section C, expose photosensitive layer 11 to light in exposure section C to form a duplicate hologram, and then convey photosensitive layer 11 again, repeating this process to continuously produce a plurality of duplicate holograms.

[0017] <Processed Material Including Photosensitive Layer> The photosensitive layer 11 is made of an unexposed photosensitive material. Examples of photosensitive materials that can be used include photopolymers, photoresists, silver halide emulsions, and dichromated gelatin. The photosensitive layer 11 typically has a thickness of several μm to 20 μm, and therefore is often not strong enough to withstand transport through the manufacturing equipment A. For this reason, the photosensitive layer 11 is typically formed on a long, strip-shaped support substrate 12. The support substrate 12 is not particularly limited as long as it has a refractive index approximately equal to that of the light-transmitting plate. Examples include glass, TAC (triacetylcellulose), and resins such as polycarbonate. The thickness of the support substrate 12 is not particularly limited and is approximately 10 μm to 100 μm. Hereinafter, a material consisting of the support substrate 12 and the photosensitive layer 11 formed solidly on one side of the support substrate 12 will be referred to as the "processed material 1."

[0018] The long strip-shaped material 1 to be treated may be wound into a roll for storage, transportation, etc. However, it is preferable to attach a protective film 15 or the like to the material 1 to prevent scratches on the support substrate 12 and the photosensitive layer 11. For example, an adhesive-backed protective film 15 is attached to the support substrate 12 side of the material 1 to be treated. A release liner 16 is attached to the photosensitive layer 11 side of the material 1 to be treated. The release liner 16 is then attached for two purposes. One is to protect the photosensitive layer 11. The other is to conceal the slight adhesiveness of the photosensitive layer 11, which has slight adhesiveness, and prevent blocking when the material 1 to be treated is wound into a roll. In this way, the laminated film consisting of the adhesive-backed protective film 15 / material 1 to be treated (support substrate 12 + photosensitive layer 11) / release liner 16 is wound into a roll and loaded into the unwinding section of the manufacturing apparatus A.

[0019] <Conveying section> Conveying section B unwinds the laminate film including the material to be treated 1 wound around a roll and conveys the unwound laminate film including the material to be treated 1 in its longitudinal direction. Specifically, conveying section B has an unwinding section 21 that loads the laminate film wound around a roll, a film peeling section 22 that peels the protective film 15 together with the adhesive from the laminate film and takes it up, a liner peeling section 23 that peels the release liner 16 from the laminate film and takes it up, accumulation mechanisms 241, 242 that allow the material to be treated 1 that is intermittently conveyed to accumulate, thereby enabling the material to be treated 1 to be continuously unwound and taken up, a film laminating section 25 that bonds the protective film 15 with adhesive to the material to be treated 1 that has been exposed to light, a liner laminating section 26 that bonds the release liner 16 to the material to be treated 1 that has been exposed to light, and a take-up section 27 that winds up the material to be treated 1 with the protective film 15 and release liner 16 bonded to it. Note that guide rolls and the like are arranged at appropriate positions on the conveying path of conveying section B. In the illustrated example, a first accumulation mechanism 241 is provided between unwinding section 21 and exposure section C, and a second accumulation mechanism 242 is provided between exposure section C and winding section 27.

[0020] Conveying unit B unwinds the laminate film containing the material 1 to be treated from unwinding unit 21 at a predetermined speed and conveys it in the longitudinal direction. Upstream of first accumulation mechanism 241, film peeling unit 22 and liner peeling unit 23 peel the adhesive-backed protective film 15 and release liner 16 from the laminate film. Conveying unit B conveys the material 1 to exposure unit C, where it temporarily stops conveying. As described below, after the exposure process for material 1 is completed in exposure unit C, conveying unit B conveys material 1 downstream in the conveying direction by a predetermined length and then stops again. By repeating this intermittent conveying process of conveying material 1, stopping conveying, exposing material 1, and conveying material 1 again, multiple duplicate holograms can be continuously produced in the long strip-shaped photosensitive layer 11.

[0021] After the exposure process is completed, the film laminating unit 25 and the liner laminating unit 26 laminate another adhesive-backed protective film 15 and release liner 16 to the treated material 1, and the winding unit 27 winds up the treated material 1 with the bonded protective film 15 and release liner 16 at a predetermined speed. The first accumulation mechanism 241 temporarily retains the treated material 1 being unwound from the unwinding unit 21 while the transport of the treated material 1 is stopped at the exposure unit C, and releases the retained treated material 1 when the treated material 1 that was stopped at the exposure unit C begins to be transported again. The second accumulation mechanism 242 releases the treated material 1 being wound up by the winding unit 27 while the transport of the treated material 1 is stopped at the exposure unit C, and temporarily retains the treated material 1 when the treated material 1 that was stopped at the exposure unit C begins to be transported again. 1, accumulation rolls that move up and down are used as the first accumulation mechanism 241 and the second accumulation mechanism 242. Note that a production line may be configured in which either the first accumulation mechanism 241 or the second accumulation mechanism 242 is not provided.

[0022] <Exposure Section> The exposure section C is a part of the manufacturing apparatus A that exposes the photosensitive layer 11. The exposure section C has a master layer 3 including a master hologram 31, a master mounting member 38 for mounting the master layer 3, light-transmitting plates 41, 42, and 43 arranged on the first surface side of the master layer 3, and a plate mounting member 48 for mounting the light-transmitting plates 41, 42, and 43. The workpiece 1 including the photosensitive layer 11 is interposed between the first surface of the master layer 3 and the second surfaces of the light-transmitting plates 41, 42, and 43.

[0023] (Master Layer and Master Mounting Member) Figure 5 is a bottom view of the master layer 3 as viewed from the first surface side. In other words, Figure 5 is a view of the master layer 3 (excluding the light-transmitting plate and the material to be treated 1) as viewed from the direction of the outline arrow in Figure 4. Note that since the master hologram 31 is sandwiched between the first substrate 32 and the second substrate 33, it does not appear on the surface when viewed from the first surface side, but for convenience, the master hologram 31 is also represented by a solid line in Figure 5.

[0024] 1 to 5, the master layer 3 has a plurality of master holograms 31. For example, the master layer 3 has a first substrate 32, a second substrate 33, and a plurality of master holograms 31 interposed between the first substrate 32 and the second substrate 33. The master holograms 31 are arranged at predetermined intervals along the surface of the master layer 3. That is, the master holograms 31 are arranged in m columns in the width direction and n rows in the transport direction, which is a direction perpendicular to the width direction. Here, m is an integer of 2 or greater, and n is an integer of 2 or greater. The upper limits of m and n are not particularly limited, but are each independently, for example, 20 or less, preferably 15 or less. Note that a "row" refers to a group arranged in the width direction, and a "column" refers to a group arranged in the transport direction (corresponding to the longitudinal direction of the workpiece 1). In the illustrated example, a total of nine master holograms 31 are provided on the master layer 3, arranged 3 x 3. Specifically, the master holograms 31 are arranged in three rows in the transport direction of the material 1 to be processed and in three columns in the width direction of the material 1 to be processed, with a gap between each row and each column. Thus, in the illustrated example, three master holograms are arranged in each of the first row S-1, second row S-2, and third row S-3, and three master holograms are arranged in each of the first column R-1, second column R-2, and third column R-3. However, the number and arrangement of the master holograms 31 provided on the master layer 3 are not limited to the three rows and three columns and can be changed as appropriate. The first and second substrates 32 and 33 are not particularly limited as long as they are base materials having a refractive index substantially equal to that of the light-transmitting plate, and may be made of, for example, glass, TAC (triacetyl cellulose), polycarbonate, or other resins.

[0025] Here, a method for manufacturing a master layer containing a master hologram will be briefly described. A master hologram can be manufactured by a conventionally known method. FIG. 10 is a reference diagram schematically illustrating the process of manufacturing a master hologram. As shown in FIG. 10( a), a photosensitive layer 1100 made of a photosensitive material is prepared. Examples of the photosensitive material that can be used include photopolymer, photoresist, silver halide emulsion, and dichromated gelatin. In the illustrated example, the photosensitive layer 1100 is interposed between the first and second substrates 3200 and 3300. However, the master hologram may be manufactured using only the photosensitive layer 1100, or may be manufactured using a substrate in which the photosensitive layer 1100 is provided on the first substrate 3200. Next, a master hologram is produced by irradiating photosensitive layer 1100 with light IL of a predetermined wavelength from two different directions (a direction forming an angle α with respect to the XY plane (hereinafter referred to as the "α direction") and a direction forming an angle β with respect to the XY plane (hereinafter referred to as the "β direction"). Specifically, by irradiating photosensitive layer 1100 with interference light of laser light of a predetermined wavelength from two directions, the monomer component in the irradiated portion of photosensitive layer 1100 is diffused, resulting in a refractive index distribution. As a result, interference fringes are recorded in the irradiated portion, resulting in master hologram 3100. In order to maintain coherence, it is preferable that the light IL of the predetermined wavelength is irradiated from two directions after light emitted from the same laser oscillator is split by a polarizing beam splitter, the polarization axis of one of the split light beams is rotated by a half-wave plate to coincide with the polarization axis of the other light beam, and the light is magnified and flattened by a magnifying lens and a collimating lens, respectively.

[0026] As shown in FIG. 1B, master hologram 3100 manufactured as described above is irradiated with laser light IL100 of the predetermined wavelength from one direction (β direction) of the two directions (α direction, β direction) in which laser light of the predetermined wavelength was irradiated when master hologram 3100 was produced. In other words, laser light IL100, which is the reproduction light, is irradiated at an angle at which master hologram 3100 is reproduced. The light is then diffracted in the other direction (α direction) (diffracted light IL200). When laser light of a red wavelength is irradiated, a red master hologram is generated; when laser light of a green wavelength is irradiated, a green master hologram is generated; and when light of a blue wavelength is irradiated, a blue master hologram is generated.

[0027] Returning to FIG. 4 , a light-absorbing layer 35 is provided on the second surface of the master layer 3. Hereinafter, to distinguish the light-absorbing layer 35 provided on the master layer 3 from a light-absorbing layer provided on a light-transmitting plate, the light-absorbing layer 35 provided on the master layer 3 will be referred to as the "master light-absorbing layer 35." The master light-absorbing layer 35 is laminated at least in an area of ​​the second surface of the master layer 3 that corresponds to the master hologram 31. In the illustrated example, the master light-absorbing layer 35 is laminated over substantially the entire second surface of the master layer 3. Note that when the master layer 3 consists of only the master hologram 31 or the master hologram 31 and the first substrate 32, the master light-absorbing layer 35 may be laminated at least on the second surface of the master hologram 31. The master light-absorbing layer 35 is provided to absorb the light that has passed through the master hologram 31 when part of the coherent light passes through the master hologram 31.

[0028] The material for forming the master light-absorbing layer 35 is not particularly limited, provided that it contains an absorbent capable of absorbing the coherent light. Examples of such absorbents include black colorants such as carbon black, organic dyes, pigments primarily composed of metal oxides, inorganic substances such as metal particles, and other organic substances. The light that an absorbent can absorb typically depends on the wavelength of the light, so the absorbent is selected taking into account the wavelength of the coherent light. For example, as described below, if red, green, and blue laser beams are selectively used as coherent light during exposure, the light-absorbing layer is formed from a material containing an absorbent capable of absorbing all of these laser beams in the visible light range. A typical example of such an absorbent is a black colorant. Alternatively, a mixed absorbent may be used, for example, comprising a first absorbent that absorbs light with a wavelength of 600 nm to 900 nm, a second absorbent that absorbs light with a wavelength of 450 nm to 750 nm, and a third absorbent that absorbs light with a wavelength of 300 nm to 550 nm. The master light-absorbing layer 35 can be formed by applying a forming material containing an absorbent such as the black colorant, an appropriate binder resin, and any additives to the second surface of the master layer 3. The thickness of the master light-absorbing layer 35 is not particularly limited and is, for example, several μm to 100 μm.

[0029] The master layer 3 is attached to a master mounting member 38. The master mounting member 38 has a holder 381 that holds the master layer 3 and a moving mechanism 382 that moves the holder 381. The moving mechanism 382 moves the holder 381 holding the master layer 3 to move the master layer 3 closer to or farther from the workpiece 1. In the example of FIG. 1 , the workpiece 1 is transported substantially horizontally in the exposure section C, so the moving mechanism 382 moves the master layer 3 up and down. As shown by the two-dot chain line in FIG. 4 , the moving mechanism 382 moves the holder 381 holding the master layer 3 upward, thereby moving the master layer 3 away from the workpiece 1. Furthermore, the moving mechanism 382 moves the holder 381 downward, thereby bringing the master layer 3 into substantial contact with the workpiece 1. The moving mechanism 382 can be a conventional actuator such as a pneumatic cylinder or a rack-and-pinion. The movement mechanism 382 may be configured to be able to move the master layer 3 a predetermined amount in the width direction and / or the transport direction.

[0030] (Light-Transmitting Plates) Figure 6 is a bottom view of the light-transmitting plates 41, 42, and 43 as viewed from the first surface side. In other words, Figure 6 is a view of the light-transmitting plates 41, 42, and 43 as viewed from the direction of the white arrow in Figure 4 (excluding the material to be treated 1 and the master layer 3). With reference to Figures 1 to 4 and 6, the light-transmitting plates 41, 42, and 43 are members that support the material to be treated 1, and the material to be treated 1 is interposed between the light-transmitting plates 41, 42, and 43 and the master layer 3. The light-transmitting plates are disposed on the first surface side of the master layer 3. Note that, in order to interpose the material to be treated 1 between the light-transmitting plates 41, 42, and 43 and the master layer 3, the light-transmitting plates 41, 42, and 43 are not in close contact with the first surface of the master layer 3, but are disposed on the first surface side of the master layer 3 with a gap therebetween.

[0031] As shown in FIG. 4 , light-transmitting plates 41, 42, and 43 are provided corresponding to at least one master hologram 31. For example, if the master layer 3 includes multiple master holograms 31, one light-transmitting plate may be arranged on the first surface of the master layer 3 corresponding to all of the master holograms 31. Alternatively, one light-transmitting plate 41 may be arranged corresponding to at least one master hologram 31, and another light-transmitting plate 42 may be arranged corresponding to at least another master hologram 31. In the latter case, multiple separate light-transmitting plates are used. In the illustrated example, light-transmitting plates 41, 42, and 43 are arranged corresponding to each row of the master holograms 31. Specifically, as described above, n rows of master holograms 31 are provided on the master layer 3, and therefore n light-transmitting plates are arranged corresponding to each row. In the illustrated example, three rows and three columns of master holograms 31 are arranged, and therefore three light-transmitting plates 41, 42, and 43 are arranged corresponding to the three rows. Hereinafter, the three light-transmitting plates 41, 42, and 43 will be referred to as the "first light-transmitting plate 41," the "second light-transmitting plate 42," and the "third light-transmitting plate 43," respectively. With reference to Fig. 1 , the first light-transmitting plate 41 is located downstream in the conveying direction, the second light-transmitting plate 42 is located closer to the unwinding section 21, and the third light-transmitting plate 43 is located closer to the unwinding section 21. Therefore, the first light-transmitting plate 41 and the second light-transmitting plate 42, and the second light-transmitting plate 42 and the third light-transmitting plate 43 are adjacent to each other in the conveying direction.

[0032] The first light-transmitting plate 41 is disposed on the first surface side of the master layer 3 in correspondence with the three master holograms 31 arranged in the first row S-1. The second light-transmitting plate 42 is disposed on the first surface side of the master layer 3 in correspondence with the three master holograms 31 arranged in the second row S-2. The third light-transmitting plate 43 is disposed on the first surface side of the master layer 3 in correspondence with the three master holograms 31 arranged in the third row S-3. The first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43 are all made of strip-shaped light-transmitting plates extending in the width direction.

[0033] The first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43 may be the same shape and size, or may be the same shape but different sizes, or may be different shapes but different sizes. In the illustrated example, the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43 are the same shape and size to simplify the equipment. Hereinafter, since the second light-transmitting plate 42 and the third light-transmitting plate 43 have the same configuration as the first light-transmitting plate 41, the configuration of the first light-transmitting plate 41 will be described in detail, and a detailed description of the second light-transmitting plate 42 and the third light-transmitting plate 43 will be omitted. Regarding the second light-transmitting plate 42 and the third light-transmitting plate 43, the terms "first light-transmitting plate 41" and "first row S-1" in the following section on specific examples of the first light-transmitting plate 41 will be read as "second light-transmitting plate 42" and "second row S-2" or "third light-transmitting plate 43" and "third row S-3."

[0034] Specific Examples of the First Light-Transmitting Plate 41 FIG. 7 is a perspective view of the first light-transmitting plate 41. Note that FIG. 7 depicts the first surface of the first light-transmitting plate 41 facing upward. With reference to FIGS. 4, 6, and 7, the first light-transmitting plate 41 is formed in a rectangular parallelepiped shape with its longitudinal axis extending in the width direction. The first light-transmitting plate 41 extends in the width direction so as to overlap the three master holograms 31 arranged in the first row S-1 and their surrounding areas in a planar perspective view. The dimensions of the first light-transmitting plate 41 are equal to or larger than the dimensions of the master holograms 31, and preferably larger than the dimensions of the master holograms 31. In this specification, the "dimension" of an object such as a light-transmitting plate refers to the length of the object in a side view (the length in the transport direction in a side view). "Side view" refers to viewing the object from one side in the width direction to the opposite side. The thickness of the first light-transmitting plate 41 is set as appropriate, but it is preferable that the thickness of the first light-transmitting plate 41 be relatively large in order to minimize reflection of diffracted light. For example, the thickness of the first light-transmitting plate 41 is 10 mm to 50 mm, and preferably 25 mm to 45 mm. The first light-transmitting plate 41 is formed from a material that transmits coherent light. For example, the first light-transmitting plate 41 (light-transmitting plate) is formed from a material with a refractive index of approximately 1.5. Examples of materials with a refractive index of approximately 1.5 include glass and resins such as TAC (triacetyl cellulose) and polycarbonate. Examples of the glass include alkali-free glass, low-alkali glass, borosilicate glass, and soda-lime glass.

[0035] The first light-transmitting plate 41 is provided with light-absorbing layers 51 and 53. The light-absorbing layers 51 and 53 are provided to absorb diffracted light. The diffracted light is light that is diffracted when coherent light is incident on the master hologram 31. In this embodiment, the light-absorbing layers 51 and 53 are provided on the end faces and first surface of the first light-transmitting plate 41. The end faces are also called thickness surfaces or side surfaces and refer to surfaces of the first light-transmitting plate 41 other than the first and second surfaces. The rectangular parallelepiped first light-transmitting plate 41 has four end faces. The light-absorbing layer 51 may be provided in a solid state on all end faces, or may be provided in a solid state on at least the end face on the side where the diffracted light travels. In the illustrated example, the light-absorbing layer 51 is provided on all end faces of the first light-transmitting plate 41.

[0036] Furthermore, a light-absorbing layer 53 is also provided on the first surface of the first light-transmitting plate 41. However, in order to allow coherent light to be incident on the master hologram 31 from the first surface side of the first light-transmitting plate 41, the light-absorbing layer 53 is provided on the first surface of the first light-transmitting plate 41 in an area other than the area where coherent light is incident on the master hologram 31. Hereinafter, the "area where coherent light is incident on the master hologram 31" will be referred to as the "incident area," and the "area other than the area where coherent light is incident on the master hologram 31" will be referred to as the "non-incident area." The incident area is the area surrounded by fine dashed lines in FIGS. 6 and 7 . Note that such dashed lines are not actually drawn on the first light-transmitting plate 41. The incident area has approximately the same shape and size as the master hologram 31 in a planar view. By irradiating the incident area with coherent light, the coherent light is incident on the master hologram 31. The light-absorbing layer 53 may be provided in a solid state over the entire non-incident region of the first surface (not shown), or may be provided at least in the non-incident region (first surface) on the side where diffracted light travels. In the illustrated example, the light-absorbing layer 53 is provided not over the entire non-incident region, but in the non-incident region on the side where diffracted light travels. In other words, the light-absorbing layer 53 is provided in a part of the non-incident region. Furthermore, the edge 53a of the light-absorbing layer 53 provided on the first surface is located along or near the edge of the incident region.

[0037] The material for forming the light-absorbing layers 51 and 53 is not particularly limited, provided that it contains an absorbent capable of absorbing the diffracted light. The light-absorbing layers 51 and 53 can be formed, for example, from the materials exemplified for the master light-absorbing layer 35. To avoid redundancy, further description will be omitted, and the material and method for forming the light-absorbing layers 51 and 53 should be referred to the master light-absorbing layer 35.

[0038] 1 to 4 and 6, the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43 are attached to a plate mounting member 48 with their longitudinal end faces in close contact with each other. Both widthwise ends of the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43 are attached to the plate mounting member 48. The plate mounting member 48 is fixed to a frame (not shown) of the manufacturing apparatus A. Note that the plate mounting member 48 may be provided with a movement mechanism (not shown) so that the first light-transmitting plate 41 and the like can be moved.

[0039] The light-absorbing layers 51 and 53 are provided to absorb the diffracted light before it is reflected. The purpose of providing the light-absorbing layers 51 and 53 will now be explained. As shown in FIG. 22 , laser light incident from the glass plate side passes through the photosensitive layer and enters the master hologram. The master hologram then generates diffracted light, which then passes through the photosensitive layer. The laser light and diffracted light pass through the photosensitive layer from two directions, exposing the photosensitive layer to light, forming a duplicate hologram in that area. However, the diffracted light that passes through the photosensitive layer may be internally reflected at the air interface of the glass plate (the bottom surface in the illustrated example), and the reflected light (reflected diffracted light) may pass through the duplicate hologram again. If the reflected light passes through again, the interference fringes of the duplicate hologram will be disrupted, making it impossible to produce a duplicate hologram with interference fringes similar to those of the master hologram. Therefore, in this embodiment, light-absorbing layers are provided to absorb the diffracted light before it is reflected.

[0040] For this purpose, the light-absorbing layers 51, 53 may be provided in an appropriate range on the first surface and / or end surface of the light-transmitting plate, taking into consideration the dimensions of the coherent light, the diffraction angle of the diffracted light, the thickness of the light-transmitting plate (such as the first light-transmitting plate 41), etc. For example, as described above, when the light-absorbing layer 53 is provided on the first surface of the light-transmitting plate (such as the first light-transmitting plate 41) so that the edge 53a of the light-absorbing layer 53 is located along or near the edge of the incident area, by satisfying the relationship of the following formula (1), almost all of the diffracted light can be absorbed by the light-absorbing layers 51, 53 without internal reflection. Formula (1): h>d / tan θ where h represents the thickness of the light-transmitting plate, d represents the dimension at the incident position of the coherent light, and θ represents the diffraction angle of the diffracted light. In formula (1), d refers to the dimension of the coherent light itself when the dimension of the coherent light is equal to or smaller than the dimension of the master hologram at the incident position of the coherent light, and refers to the dimension of the master hologram when the dimension of the coherent light is larger than the dimension of one master hologram. The diffraction angle of the diffracted light refers to the angle between the normal direction of the first surface of the master hologram and the propagation direction of the diffracted light.

[0041] Figure 8 is a reference side view showing the state of diffracted light when the relationship of formula (1) is satisfied. In this specification, the term "reference side view" refers to a side view that shows the internal components in a perspective view. In Figure 8, coherent light L1 is shown by a solid line, and diffracted light L2 is shown by a dashed line.

[0042] As shown in FIG. 8 , diffracted light L2 generated from the master hologram 31 by irradiation with coherent light L1 is almost entirely absorbed by the light-absorbing layers 51 and 53. This allows a replica hologram having interference fringes similar to those of the master hologram 31 to be formed in the photosensitive layer 11. Specifically, light-absorbing layers 51 and 53 are provided on the end faces and first surface of the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43. Therefore, as shown in FIG. 8 , coherent light L1 incident from the incident area on the first surface of the first light-transmitting plate 41 is diffracted at a predetermined diffraction angle (e.g., an acute diffraction angle) recorded in the master hologram 31 in the first row S−1, generating diffracted light L2. When the diffracted light L2 first strikes the first surface and end surface of the first light-transmitting plate 41, the diffracted light is absorbed by the light-absorbing layers 51 and 53 without internal reflection. This prevents reflected light (diffracted light reflected by the first surface or end surface of the first light-transmitting plate 41) from being re-entered into the duplicate hologram 310 formed by exposing the photosensitive layer 11 to coherent light L1 and diffracted light L2 as they pass through the photosensitive layer 11. This prevents the interference fringes of the duplicate hologram 310 from being disturbed, making it possible to produce a duplicate hologram 310 having interference fringes similar to those of the master hologram 31. As with the first light-transmitting plate 41, the diffracted light of the second light-transmitting plate 42 and the third light-transmitting plate 43 is absorbed by the light-absorbing layers 51, 53 without being internally reflected.

[0043] Furthermore, the light-transmitting plates are divided into a plurality of pieces corresponding to the rows, such as the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43, and a light-absorbing layer 51 is provided on at least one end face of each plate on the side along which the diffracted light travels. Therefore, the diffracted light traveling through one light-transmitting plate does not enter the light-transmitting plate adjacent to that light-transmitting plate in the transport direction. In other words, because the light-transmitting plate is divided into a plurality of pieces and the light-absorbing layer 51 is provided on the end face along which the diffracted light travels, for example, the diffracted light L2 traveling through the second light-transmitting plate 42 does not enter the first light-transmitting plate 41 adjacent to the second light-transmitting plate 42, and the diffracted light L2 traveling through the third light-transmitting plate 43 does not enter the second light-transmitting plate 42 adjacent to the third light-transmitting plate 43. Therefore, for example, it is possible to prevent diffracted light L2 generated in the master hologram 31 in the second row S-2 from entering the first light-transmitting plate 41, and then the diffracted light L2 from being internally reflected and entering the duplicate hologram 310 in the first row S-1, thereby disturbing the interference fringes of the duplicate hologram 310. The first row S-1 and the second row S-2, and the second row S-2 and the third row S-3 are adjacent rows in the transport direction.

[0044] Furthermore, reflected light can be prevented from re-entering the duplicate hologram even when the relationship of the following formula (2) is satisfied: formula (2): h>d / 2 tan θ, where h, d, and θ are the same as in formula (1).

[0045] FIG. 9 is a reference side view showing the state of diffracted light when the relationship of Equation (2) is satisfied. Coherent light is represented by a solid line, diffracted light by a dashed line, and reflected light by a dashed-dotted line. As shown in FIG. 9 , diffracted light L2 generated from the master hologram 31 by irradiation with coherent light L1 is partially absorbed by the light-absorbing layers 51 and 53, but a portion of the diffracted light L2 is internally reflected at the air-interface of the entrance region of the first light-transmitting plate 41 (generating reflected light L3). When the relationship of Equation (2) is satisfied, the reflected light L3 is less likely to enter the replica hologram. Specifically, as shown in FIG. 9 , a portion of the diffracted light L2 is absorbed by the light-absorbing layers 51 and 53 provided on the first surface and end surface of the first light-transmitting plate 41 and is not reflected. A portion of the diffracted light L2 travels to the entrance region of the first surface of the first light-transmitting plate 41, is internally reflected at the entrance region, and reflected light L3 travels back into the first light-transmitting plate 41. When the relationship of formula (2) is satisfied, the reflected light L3 is unlikely to be incident on the duplicate hologram 310 formed in the photosensitive layer 11, and instead proceeds to the master layer 3. Note that, because a master light-absorbing layer 35 is provided on the second surface of the master layer 3, the reflected light L3 that has passed through the master layer 3 is absorbed by the master light-absorbing layer 35. This prevents the reflected light L3 from repeatedly reflecting and entering the duplicate hologram 310. Even when the relationship of formula (2) is satisfied, the interference fringes of the duplicate hologram 310 are not disturbed by the reflected light, and a duplicate hologram 310 having interference fringes similar to those of the master hologram 31 can be produced. The second light-transmitting plate 42 and the third light-transmitting plate 43 are similar to the first light-transmitting plate 41.

[0046] Note that neither Equation (1) nor Equation (2) takes into account the thickness of the material to be treated 1. In other words, in Equation (1) and Equation (2), it would be more accurate to define h as "the thickness of the light-transmitting plate + the thickness of the material to be treated 1." However, the thickness of the material to be treated 1 (the thickness of the photosensitive layer 11 and the thickness of the supporting substrate 12) is much smaller than the thickness of the light-transmitting plate. Therefore, it is believed that the above-mentioned effects can be achieved by satisfying the relationship between Equation (1) and Equation (2) even without considering the thickness of the material to be treated 1. Note that in each figure, the thickness of the material to be treated 1 (the photosensitive layer 11 and the supporting substrate 12) is exaggerated, particularly to make the material to be treated 1 easier to understand. For this reason, h is defined as "the thickness of the light-transmitting plate." However, if necessary, h in Equation (1) and Equation (2) may be defined as "the thickness of the light-transmitting plate + the thickness of the material to be treated."

[0047] (Others) The exposure section C is provided with a pressure roll 28 for adhering the material 1 to the light-transmitting plate. The exposure section C also includes an index oil injector and an index oil remover (both not shown) that are interposed between the master layer 3 and the material 1 to prevent an air interface from forming between the master layer 3 and the material 1. A bleaching section 29 is provided downstream of the exposure section C. The bleaching section 29 irradiates the material 1 with UV / VIS light of a relatively high intensity, but not enough to damage the material forming the photosensitive layer 11. The exposure bleaches the exposed photosensitive layer 11, completing the photoreaction of the photosensitive layer 11 (both the areas irradiated with coherent light and the areas not irradiated with coherent light).

[0048] 1 and 3, in the exposure section C, a light source D irradiates a stack including a photosensitive layer 11 with coherent light L1. The light source D has a position change mechanism that changes the irradiation position of the coherent light L1 relative to the master hologram 31. The position change mechanism changes the irradiation position between a first position where the coherent light L1 is irradiated onto a plurality of master holograms 31 extending in one row, and a second position where the coherent light L1 is irradiated onto a plurality of master holograms 31 extending in another row.

[0049] Laser light is typically used as the coherent light L1. There are no particular limitations on the wavelength of the laser light, but when the replicated hologram is incorporated into, for example, an AR (Augmented Reality) device, it is preferable to use laser light in the visible light region. For example, it is preferable to use laser light with a red wavelength, green wavelength, or blue wavelength. In the present invention, "red wavelength" refers to, for example, a wavelength of 600 to 700 nm, "green wavelength" refers to, for example, a wavelength of 500 to 560 nm, and "blue wavelength" refers to, for example, a wavelength of 430 to 500 nm. There are also no particular limitations on the type of laser light, and examples include solid-state lasers, liquid lasers, gas lasers, and semiconductor lasers.

[0050] The light source D has a laser oscillator 61, a reflector 62 that changes the direction of laser light from the laser oscillator 61 and causes the laser light to travel toward a laminate including a photosensitive layer 11, and various optical devices arranged between the laser oscillator 61 and the reflector 62, and the reflector 62 is equipped with the position change mechanism unit 63.

[0051] The laser oscillator 61 emits laser light of a predetermined wavelength. In one embodiment, a laser oscillator 61 that emits laser light of a visible light wavelength is used. Examples of such laser oscillators 61 include a red laser oscillator that emits laser light of a red wavelength (referred to as red laser light), a green laser oscillator that emits laser light of a green wavelength (referred to as green laser light), and a blue laser oscillator that emits laser light of a blue wavelength (referred to as blue laser light). For example, a 640 nm laser oscillator manufactured by Cobolt (product name "Cobolt 05-01 Series Bolero") can be used as the red laser oscillator. A 532 nm laser oscillator manufactured by Cobolt (product name "Cobolt 05-01 Series Samba") can be used as the green laser oscillator. A 460 nm laser oscillator manufactured by Coherent (product name "Genesis MX460") can be used as the blue laser oscillator.

[0052] In the illustrated example, the light source D has three laser oscillators 61 (a first oscillator 611, a second oscillator 612, and a third laser oscillator 613) that emit coherent light beams of different wavelengths. For example, the first oscillator 611 is a red laser oscillator, the second oscillator 612 is a green laser oscillator, and the third oscillator 613 is a blue laser oscillator. The number of laser oscillators 61 provided in the light source D is not limited to three, and may be one, two, or four or more.

[0053] The reflector 62 is not particularly limited as long as it can reflect the laser light, which is the coherent light L1, and may be, for example, a mirror. Examples of optical devices include a shutter, a magnifying lens, a collimating lens, a half-wave plate, a dielectric multilayer mirror, and a beam splitter, and any of these may be appropriately selected and placed on the optical path.

[0054] 3 shows one example of the configuration of the light source D. Arranged on the optical path of the first oscillator 611 are, in this order, a shutter 6111, a dielectric multilayer mirror 6112, a magnifying lens 6113, a collimating lens 6114, a half-wave plate 6115, and a dielectric multilayer mirror 6116. Red laser light of a predetermined wavelength emitted from the first oscillator 611 is magnified and flattened by the magnifying lens 6113 and the collimating lens 6114, has its polarization direction adjusted by the half-wave plate 6115, and is then reflected by the dielectric multilayer mirror 6116. The shutter is a device that controls the blocking and transmission of light, and the dielectric multilayer mirror is a device that reflects light of a specific wavelength with a high reflectance. On the optical path of the second oscillator 612, a shutter 6121, a dielectric multilayer mirror 6122, a magnifying lens 6123, a collimating lens 6124, a half-wave plate 6125, and a Dylomic mirror 6126 are arranged in this order. Green laser light of a predetermined wavelength emitted from the second oscillator 612 is similarly magnified and flattened and reflected by the Dylomic mirror 6126. The Dylomic mirror 6126 is a mirror that selectively reflects light of a specific wavelength, transmitting red laser light and reflecting green laser light. On the optical path of the third oscillator 613, a shutter 6131, a dielectric multilayer mirror 6132, a magnifying lens 6133, a collimating lens 6134, a half-wave plate 6135, and a Dylomic mirror 6136 are arranged in this order. The blue laser light of a predetermined wavelength emitted from the third oscillator 613 is similarly expanded and flattened, and reflected by the dylomic mirror 6136. The dylomic mirror 6136 is a mirror that selectively reflects light of a specific wavelength, and transmits red and green laser lights and reflects blue laser light.

[0055] Furthermore, the red, green, and blue laser beams travel the same optical path after the Dylomic mirror 6136. A shutter 71 and a broadband dielectric multilayer mirror 72 are provided after the Dylomic mirror 6136. The laser beam reflected by the mirror 72 is split into multiple beams. The laser beam is split into the same number of beams as the number of master holograms 31 in one row. In other words, the laser beam is split into the same number of beams as the number of columns of master holograms 31 in the master layer 3. As described above, the master layer 3 has three columns of master holograms 31 (three per row), so the laser beam reflected by the broadband dielectric multilayer mirror 72 is split into three beams. For example, a first polarizing beam splitter 731, a second polarizing beam splitter 732, and a broadband dielectric multilayer mirror 74 are provided to split the laser beam. A half-wave plate 75, a magnifying lens 76, and a collimating lens 77 are provided after the first polarizing beam splitter 731, the second polarizing beam splitter 732, and the wideband dielectric multilayer mirror 74, respectively. The laser light reflected by the wideband dielectric multilayer mirror 72 is split by the first polarizing beam splitter 731 into P waves and S waves at a ratio depending on the orientation at the half-wave plates 6115, 6125, and 6135. The split S waves proceed to the half-wave plate 75, where their polarization orientation is adjusted, and then expanded and collimated by the magnifying lens 76 and the collimating lens 77. The split P waves proceed to the half-wave plate 78, where their polarization orientation is adjusted, and then expanded by the second polarizing beam splitter 732 into P waves and S waves at a ratio depending on the orientation at the half-wave plate. The split S waves proceed to the half-wave plate 75, where they are expanded and collimated. The branched P wave is reflected by a wideband dielectric multilayer mirror 74, and then travels to a half-wave plate 75 where it is expanded and collimated.

[0056] Each of the multiple laser beams thus branched is irradiated onto the master hologram 31. Reflectors 62 are provided to direct each laser beam toward the master hologram 31. In this embodiment, the number of reflectors 62 provided is the same as the number of laser beams (the number of columns of the master hologram 31). In the illustrated example, three reflectors 62 are provided. Each reflector 62 changes the direction of laser beams traveling from the oscillator through the optical device to the collimator lens 77 toward the master hologram 31. A shaping mask member 79 is disposed between the collimator lens 77 and the reflector 62. The expanded and parallel laser beam (coherent light) has a circular shape, but by passing through the mask member 79, it is shaped to the shape of the opening 791 of the mask member 79. For example, the laser beam is shaped through the mask member 79 into a shape substantially identical to that of the master hologram 31. In the illustrated example, since the master hologram 31 has a rectangular shape in a plan view, the laser light is shaped into a substantially rectangular shape, for example, substantially the same shape and size as the master hologram 31 .

[0057] In order to change the irradiation position of the laser light, the light source D is provided with a position change mechanism 63. For example, the position change mechanism 63 is provided on the reflector 62. In this embodiment, a plurality of reflectors 62 are provided, and each of the reflectors 62 is provided with a position change mechanism 63. The position change mechanism 63 includes a fixed unit 631, a moving unit 632, and a drive unit (not shown) that moves the moving unit 632 relative to the fixed unit 631. The fixed unit 631 is, for example, a uniaxial stage, and is fixed to a frame (not shown) of the manufacturing apparatus A. Although not specifically shown, the components of the light source D other than the moving unit 632 (such as the oscillator 61) are fixed to a stage base (not shown) provided on the frame of the manufacturing apparatus A. The moving unit 632 is provided with the reflector 62. The moving part 632 (and the reflector 62 provided on the moving part 632) can be moved on the fixed part 631 along the conveying direction of the material to be treated 1 by a drive part (not shown). For example, the moving part 632 (and the reflector 62) can slide upstream and downstream in the conveying direction along rails 6311 formed on the fixed part 631. Each moving part 632 (and each reflector 62) can move independently or simultaneously in the conveying direction of the material to be treated 1. In the illustrated example, each moving part 632 (and each reflector 62) is configured to be able to move simultaneously in the conveying direction of the material to be treated 1.

[0058] The position changing mechanism 63 moves the reflector 62 to a first position where the laser light (coherent light L1) is irradiated onto a plurality of master holograms 31 extending in one row, the Nth row (N is an integer greater than or equal to 1 and less than or equal to n-1), and to a second position where the laser light (coherent light L1) is irradiated onto a plurality of master holograms 31 extending in another row, the N+1th row. For example, as shown in FIGS. 1 and 3 , the position changing mechanism 63 positions each reflector 62 at the first position so that the coherent light L1 can be irradiated onto each master hologram 31 in the first row. Furthermore, each reflector 62 can be moved by the position changing mechanism 63 to a second position so that the coherent light L1 can be irradiated onto each master hologram 31 in the second row, as shown by the two-dot chain line in FIG. 1 . Furthermore, each reflector 62 can be moved by a position changing mechanism 63 to a third position so that the coherent light L1 can be irradiated onto each master hologram 31 in the third row.

[0059] {Hologram Manufacturing Method} Next, a hologram manufacturing method will be described. The manufacturing apparatus A described above is used to manufacture a replica hologram using the master hologram 31. As shown in FIG. 11 , a reflector 62 is positioned at a first position corresponding to the first row S-1 to irradiate the multiple master holograms 31 extending in the first row S-1 with coherent light L1. Meanwhile, the moving mechanism 382 separates the master layer 3 from the support substrate 12 of the workpiece 1, and the transport unit B transports the workpiece 1 downstream in the transport direction by a predetermined length, after which transport of the workpiece 1 in the exposure unit C is stopped. The predetermined length corresponds to the portion of the photosensitive layer 11 for which exposure processing has been completed. Next, the pressure roll 28 is moved downstream in the transport direction while in contact with the second surface of the support substrate 12 (the movement of the pressure roll 28 is indicated by a two-dot chain line). This brings the first surface of the photosensitive layer 11 of the workpiece 1 into close contact with the second surface of the light-transmitting plate. Since the photosensitive layer 11 has slight adhesiveness, the photosensitive layer 11 of the material to be processed 1 can be brought into close contact with the second surface of the light-transmitting plate without creating an air interface between the photosensitive layer 11 and the light-transmitting plate by lightly pressing the material to be processed 1 with the pressure roll 28. Thereafter, as shown in Figure 1, the moving mechanism 382 moves the master layer 3 closer to the support substrate 12 of the material to be processed 1.

[0060] A gap exists between the first surface of the master layer 3 and the support substrate 12 of the workpiece 1, and the presence of this gap creates an air interface. Therefore, an index oil is injected and filled between the first surface of the master layer 3 and the support substrate 12 of the workpiece 1 using an index oil injector (not shown). Figure 4 shows the state after the index oil 39 has been injected. The index oil 39 is an oil with a refractive index approximately equal to that of the light-transmitting plate. In this way, a laminate consisting of the master layer 3 / index oil 39 / workpiece 1 (support substrate 12 + photosensitive layer 11) / light-transmitting plates 41, 42, 43, with no air interface between the layers, is temporarily formed in the exposure section C.

[0061] 1 and 3 , coherent light L1 is irradiated onto master hologram 31 from the first surface side of light-transmitting plate 41 of this laminate, exposing photosensitive layer 11 to form a duplicate hologram in photosensitive layer 11 having interference fringes similar to those of master hologram 31. The coherent light L1 for exposing photosensitive layer 11 may be, for example, red laser light (e.g., 640 nm laser light), green laser light (e.g., 532 nm laser light), blue laser light (e.g., 460 nm laser light), or a composite laser light containing at least two types of laser light selected from red laser light, green laser light, and blue laser light. For example, when the shutter 6111 of the first oscillator 611 is opened and the shutters 6121 and 6131 of the second oscillator 612 and the third oscillator 613 are closed, the red laser light from the first oscillator 611 is reflected by each reflector 62 and irradiated onto the master hologram 31. In this case, a red replica hologram is created in the photosensitive layer 11. When the shutter 6121 of the second oscillator 612 is opened and the shutters 6111 and 6131 of the first oscillator 611 and the third oscillator 613 are closed, the green laser light from the second oscillator 612 is reflected by each reflector 62 and irradiated onto the master hologram 31. In this case, a green replica hologram is created in the photosensitive layer 11. When the shutter 6131 of the third oscillator 613 is opened and the shutters 6111 and 6121 of the first and second oscillators 611 and 612 are closed, the blue laser light from the third oscillator 613 is reflected by each reflector 62 and irradiated onto the master hologram 31. In this case, a blue replica hologram is created in the photosensitive layer 11.

[0062] For example, when all shutters 6111, 6121, and 6131 are opened, red, green, and blue laser beams from the first to third oscillators 611, 612, and 613 are simultaneously reflected by the respective reflectors 62 and irradiated onto the master hologram 31. In this case, a red, green, and blue duplicate hologram are multiplexed and created in the photosensitive layer 11. Alternatively, two types of laser beams may be selected. For example, when shutters 6111 and 6121 are opened and shutter 6131 is closed, the red and green laser beams from the first and second oscillators 611 and 612 are reflected by the respective reflectors 62 and irradiated onto the master hologram 31. In this case, a duplicate hologram in which each interference fringe is multiplexed and recorded is created in the photosensitive layer 11. The interference fringes are interference fringes that diffract red wavelength light, interference fringes that diffract green wavelength light, and interference fringes that diffract blue wavelength light. The interference fringes diffracting the red, green, and blue wavelength light are recorded in the master hologram. Furthermore, when irradiating a composite laser beam containing at least two types of laser beams selected from red, green, and blue laser beams, the master hologram 31 may be irradiated with at least two types of laser beams in sequence. For example, red laser beam from the first oscillator 611 is irradiated onto the master hologram 31 in the first row S-1 via the reflectors 62, thereby exposing the photosensitive layer 11 to the red laser beam. Next, without moving the reflector 62, green laser beam from the second oscillator 612 is irradiated onto the master hologram 31 in the first row S-1 via the reflectors 62, thereby exposing the photosensitive layer 11 to the green laser beam. Furthermore, without moving the reflector 62, blue laser beam from the third oscillator 613 is irradiated onto the master hologram 31 in the first row S-1 via the reflectors 62, thereby exposing the photosensitive layer 11 to the blue laser beam. In this way, even when two or more types of laser light of predetermined wavelengths are irradiated sequentially, a duplicate hologram in which each interference fringe is multiplexed and recorded is produced in the photosensitive layer 11. Note that when laser light of a predetermined wavelength (e.g., red laser light) is irradiated onto the master hologram 31 to expose the photosensitive layer 11, the master hologram 31 is naturally produced using laser light of the same wavelength as the laser light of the predetermined wavelength.

[0063] Laser light irradiated from the first surface of the light-transmitting plate enters the light-transmitting plate through an incident region of the light-transmitting plate (such as first light-transmitting plate 41), passes through photosensitive layer 11, and then enters master hologram 31, generating diffracted light. The diffracted light then passes through photosensitive layer 11, thereby recording the interference fringes of master hologram 31 in photosensitive layer 11. The portion of photosensitive layer 11 where the interference fringes are recorded becomes a duplicate hologram. As described above, providing light-absorbing layers 51 and 53 on the light-transmitting plate prevents reflected light from diffracting the light from entering the duplicate hologram. This ensures the production of duplicate holograms with interference fringes similar to those of master hologram 31. In particular, providing multiple light-transmitting plates and light-absorbing layers 51 and 53 on at least one end face of each light-transmitting plate on the side where the diffracted light travels also prevents the diffracted light from entering duplicate holograms adjacent in the transport direction.

[0064] In this manner, the coherent light L1 is irradiated onto the master holograms 31 arranged in the first row S-1, thereby creating a duplicate hologram corresponding to each master hologram 31 in the first row. Preferably, the coherent light L1 is irradiated simultaneously onto all of the master holograms 31 arranged in the first row S-1. Next, the position change mechanism 63 moves each reflector 62 from the first position to a second position corresponding to the second row S-2 (see the two-dot chain line in FIG. 1 and FIG. 12). The reflectors 62 are moved simultaneously (synchronized). Note that the movement from the first position to the second position is performed after the coherent light L1 has been irradiated onto all of the master holograms 31 arranged in the first row S-1 at the first position, thereby completing the exposure of the photosensitive layer 11. In other words, the position change mechanism 63 does not operate until exposure of the photosensitive layer 11 at the first position is completed and recording of the interference fringes of the master hologram 31 in the first row S-1 on the photosensitive layer 11 is completed. After the exposure is completed, the position change mechanism 63 moves each reflector 62 from the first position to the second position. Furthermore, when each reflector 62 moves, it is preferable to prevent coherent light L1 from traveling toward each reflector 62. This prevents coherent light L1 from irradiating the photosensitive layer 11 while the reflector 62 is moving, thereby preventing coherent light from inadvertently entering an already-produced duplicate hologram (the duplicate hologram produced in the first row S-1 in the above example). Methods for preventing coherent light L1 from traveling toward each reflector 62 when each reflector 62 moves include closing the shutter 71 or stopping the emission of laser light from the oscillator 61. However, closing the shutter 71 is preferred because it is simple.

[0065] As shown in Figure 12, coherent light L1 is irradiated from the first surface side of the light-transmitting plate 42 onto the master holograms 31 arranged in the second row S-2, and a duplicate hologram corresponding to each of the master holograms 31 in the second row S-2 is created in the photosensitive layer 11. The reflector 62 is then moved to the third row S-3, and duplicate holograms are created in the same manner. After duplicate holograms corresponding to all of the master holograms 31 in the master layer 3 have been created in the photosensitive layer 11 in this manner, the master layer 3 is separated from the support substrate 12 of the workpiece 1 by the movement mechanism 382. Since index oil is usually attached to the second surface of the support substrate 12 of the workpiece 1 after the master layer 3 has been separated, the index oil attached to the support substrate 12 is removed by wiping it off using an index oil remover (not shown).

[0066] The material 1 is then transported downstream in the transport direction by a predetermined length (the length that has been exposed), and transport is then stopped. The material 1 is adhered to the second surfaces of the light-transmitting plates 41, 42, and 43 due to the slight adhesiveness of the photosensitive layer 11. Because the slight adhesiveness of the photosensitive layer 11 is very weak, the material 1 separates from the light-transmitting plates 41, 42, and 43 when the transport unit B pulls the material 1. However, if the photosensitive layer 11 is difficult to separate from the light-transmitting plates 41, 42, and 43, an appropriate peeling means may be provided in the transport unit B, or the light-transmitting plates 41, 42, and 43 may be moved away from the material 1 (not shown).

[0067] The exposed workpiece 1 is transported and stopped, and the reflector 62 is returned to the first position, returning to the state shown in FIG. 11 . This sends the exposed photosensitive layer 11 downstream, and the unexposed photosensitive layer 11 is subsequently placed in the exposure section C. After this, the master layer 3 is similarly brought into close contact with the workpiece 1 and exposed to coherent light to create duplicate holograms in the photosensitive layer 11 corresponding to all master holograms 31. The master layer 3 is then released, the workpiece 1 is transported a predetermined length, and the process is repeated. In this manner, duplicate holograms can be efficiently and continuously produced. FIG. 13( a ) is a plan view of the exposed workpiece 100. The exposed workpiece 1 has multiple duplicate holograms arranged consecutively in its photosensitive layer 11. Hereinafter, the "exposed workpiece 100" will be referred to as the "duplicate hologram continuum 100." In the above example, three rows of master holograms 31 are used, and therefore the duplicate hologram continuum 100 in FIG. 13 has a plurality of duplicate holograms 310 arranged in three rows.

[0068] 1, a bleaching process is performed on a replica hologram continuum 100 in a bleaching unit 29. A protective film 15 and a release liner 16 are laminated to the bleached replica hologram continuum 100 in a film laminating unit 25 and a liner laminating unit 26, respectively, and the resulting product is then wound up in a winding unit 27.

[0069] If necessary, the replicate hologram continuum 100 may be divided into individual rows of replicate holograms, and then the individual rows may be wound up on the winding section 27. For example, as shown in Figure 13(b), a double-row replicate hologram continuum 100 may be divided into single-row replicate hologram continuums 100 using a slitter 290, and these may then be wound up individually. It is generally preferable that the division by the slitter 290 be carried out after the protective films 15 and release liners 16 have been bonded to each other.

[0070] <Uses of Replica Holograms> Individual replica holograms can be obtained by cutting the replica hologram continuum 100 at appropriate locations. The uses of the replica hologram are not particularly limited. The replica hologram of the present invention can be applied to various applications that have been publicly known or will become publicly known in the future. Replica holograms can be used, for example, in optical-related products such as light guide plates; security-related products such as anti-counterfeit seals and authentication seals; and design-related products such as decorative items. A light guide plate according to one embodiment has a hologram manufactured using the above-described manufacturing apparatus and manufacturing method. For example, a light guide plate can be manufactured by sandwiching a replica hologram between two glass plates or transparent resin plates. Furthermore, a light guide plate for an AR device can also be manufactured using the replica hologram. An AR (Augmented Reality) device is a device, such as smart glasses, that can display text information and virtual content simultaneously with the real world. In such a device, light corresponding to text information or virtual content (light of red wavelength, light of green wavelength, and light of blue wavelength) is guided by a light guide plate to a position where light from the real world is received.

[0071] For example, the above-described manufacturing apparatus A (or manufacturing method) can also produce a duplicate hologram set consisting of one rectangular hologram called an incoupling and one large rectangular hologram called an outcoupling. As shown in Fig. 14, a red duplicate hologram 310R consisting of incoupling 311R and outcoupling 312R, a green duplicate hologram 310G consisting of incoupling 311G and outcoupling 312G, and a blue duplicate hologram 310B consisting of incoupling 311B and outcoupling 312B are laminated in this order, and glass plates or transparent resin plates are laminated on the front and back surfaces of the laminate, thereby forming a light guide plate G for an AR device.

[0072] The second embodiment will be described below. In this description, the configuration and effects that differ from those of the above-described embodiment will be mainly described. For similar configurations, the terms or symbols will be used as they are, and the description of the configuration may be omitted (the same applies to the third embodiment and beyond).

[0073] [Second Embodiment] In the second embodiment, a position changing mechanism 63 changes the irradiation position between a first position where coherent light L1 is irradiated onto a plurality of master holograms 31 extending in one row, and a second position where coherent light is irradiated onto a plurality of master holograms 31 extending in another row. Fig. 15 is a perspective view showing an exposure section C and a light source D in a manufacturing apparatus A of the second embodiment. However, in Fig. 15, both sides of the long strip-shaped workpiece are omitted, and further, for the light source D, a reflector 62 and a position changing mechanism 63 are shown.

[0074] Referring to FIG. 15 , as in the first embodiment, the master holograms 31 are arranged in m columns in the width direction and n rows in the transport direction, which is perpendicular to the width direction. In the illustrated example, a total of nine master holograms 31 (3×3) are provided on the master layer 3. The position change mechanism 63 moves the reflector 62 between a first position where laser light (coherent light L1) is irradiated onto a plurality of master holograms 31 extending in one column, the Mth row (M is an integer greater than or equal to 1 and less than or equal to m−1), and a second position where the laser light (coherent light L1) is irradiated onto a plurality of master holograms extending in another row, the M+1th row. Specifically, the moving unit 632 of the position change mechanism 63 is movable in the width direction relative to the fixed unit 631. Therefore, each reflector 62 provided on the moving unit 632 is movable along the width direction of the workpiece 1. 15, each reflector 62 is disposed at a first position by a position change mechanism 63 so that coherent light L1 can be applied to each master hologram 31 in a first column R-1. Furthermore, each reflector 62 can be moved by a position change mechanism 63 to a second position so that coherent light L1 can be applied to each master hologram 31 in a second column R-2, as shown by the two-dot chain line in FIG. 15. Furthermore, each reflector 62 can be moved by a position change mechanism 63 to a third position so that coherent light L1 can be applied to each master hologram 31 in a third row R-3.

[0075] A brief description of hologram production using the manufacturing apparatus A of this embodiment will be given. As shown in FIG. 15 , in order to irradiate the multiple master holograms 31 extending in the first row R-1 with coherent light L1, a reflector 62 is positioned at a first position corresponding to the first row R-1. The transport unit B transports the material 1 a predetermined length and then stops the transport. The pressure roll 28 brings the photosensitive layer 11 into close contact with the second surface of the light-transmitting plate 41. The master layer 3 is brought close to the material 1 and filled with index oil 39. Next, the multiple master holograms 31 in the first row R-1 are irradiated with coherent light L1 from the first surface side of the light-transmitting plates 41, 42, and 43. This creates duplicate holograms in the photosensitive layer 11 corresponding to the master holograms 31 in the first row R-1. The position change mechanism 63 moves the reflector 62 in the width direction to position the reflector 62 at a second position corresponding to the second row R-2. Movement from the first position to the second position is performed after all of the master holograms 31 arranged in the first row R-1 at the first position have been irradiated with coherent light L1, completing exposure of the photosensitive layer 11. Coherent light L1 is irradiated onto the master holograms 31 in the second row R-2, creating duplicate holograms in the photosensitive layer 11 that correspond to the master holograms 31 in the first row R-2. The reflector 62 is then moved to the third row R-3, and duplicate holograms are created in the same manner.

[0076] Third Embodiment In the first embodiment, the light source D has the same number of reflectors 62 as the number of columns of the master hologram 31. However, this is not limited to the case where the number of reflectors 62 of the light source D is the same as the number of columns of the master hologram 31. For example, as shown in FIG. 16 , there may be only one reflector 62. This reflector 62 simultaneously changes the traveling direction of all coherent light L1 toward each master hologram 31. Although not specifically shown, there may also be two reflectors 62, and the number of reflectors 62 can be changed as appropriate. In the second embodiment, the number of reflectors 62 is the same as the number of rows of the master hologram 31. Similarly, there may also be one or two reflectors 62, as appropriate.

[0077] [Fourth Embodiment] In the first and second embodiments, the laser light emitted from each oscillator 61 travels along the same optical path along the way, but this is not limited to this. For example, as shown in Fig. 17, the laser light emitted from each oscillator 61 may travel along independent optical paths and be incident on the master hologram 31 via a reflector 62. In the illustrated example, a shutter 71, a half-wave plate 75, a magnifying lens 76, and a collimating lens 77 are arranged in this order after each of the first to third oscillators 611, 612, and 613. However, the arrangement of the optical devices is not limited to the example of Fig. 17.

[0078] [Fifth Embodiment] In the first and second embodiments, the longitudinal end faces of the plurality of light-transmitting plates (e.g., the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43) are in close contact with each other. However, as shown in FIG. 18 , there may be gaps between adjacent light-transmitting plates (e.g., the first light-transmitting plate 41, the second light-transmitting plate 42, and the third light-transmitting plate 43).

[0079] Furthermore, while the first and second embodiments described above use multiple separate light-transmitting plates, a single light-transmitting plate 44 may be used, as shown in FIG. 19 . That is, a single light-transmitting plate 44 corresponding to all master holograms 31 may be disposed on the first surface side of the master layer 3. When a single light-transmitting plate 44 corresponding to all master holograms 31 is used, a light-absorbing layer 53 is provided in at least the non-incident region of the first surface of the light-transmitting plate 44, and preferably, a light-absorbing layer 51 is also provided on the end surface of the light-transmitting plate 44. As shown in FIG. 15 , the light-absorbing layer 53 provided on the first surface of the light-transmitting plate 44 preferably has a dimension equal to or greater than the dimension d of the coherent light. This allows the diffracted light L2 to be absorbed by the light-absorbing layer 53. By disposing a single light-transmitting plate 44 corresponding to all holograms and providing a light-absorbing layer 53 on its first surface with a dimension equal to or greater than the dimension d of the coherent light, as in this embodiment, the diffracted light L2 can be prevented from being internally reflected at the first surface. However, in this embodiment, the interval between adjacent master holograms 31 in the transport direction (for example, between the master hologram 31 in the first row S-1 and the master hologram 31 in the second row S-2, or between the master hologram 31 in the second row S-2 and the master hologram 31 in the third row S-3) must be relatively large. In this regard, by using light-transmitting plates 41, 42, and 43 that are separated into rows and have light-absorbing layers 51 on their end faces, as in the first embodiment, the diffracted light L2 can be absorbed by the light-absorbing layers 51 and 53 even if the interval between adjacent master holograms 31 in the transport direction is relatively small. Therefore, by using light-transmitting plates 41, 42, and 43 that are separated into multiple plates and have light-absorbing layers 51, as in the first and second embodiments, the interval between adjacent master holograms 31 can be made small, which has the advantage of allowing more duplicate holograms to be produced per unit length of the processed material 1.

[0080] [Sixth embodiment] In the first and second embodiments, the photosensitive layer 11 of the material to be processed 1 is brought into close contact with the light-transmitting plates 41, 42, and 43 in the exposure section C. However, as shown in Fig. 20, the material to be processed 1 may be turned over so that the photosensitive layer 11 of the material to be processed 1 is brought into close contact with the master layer 3. In this case, an air interface is created between the support substrate 12 of the material to be processed 1 and the second surface of the light-transmitting plate, and index oil 39 may be filled between the two.

[0081] Seventh Embodiment In the first and second embodiments described above, coherent light having substantially the same dimensions as the master hologram 31 is irradiated from the first surface side of the light-transmitting plate. However, this is not limiting. For example, as shown in FIG. 21A, coherent light L1 having a dimension d smaller than the dimension 31W of the master hologram 31 may be irradiated. In this case, a replica hologram 310 having a smaller area than the master hologram 31 is formed in the photosensitive layer 11. Furthermore, as shown in FIG. 21B, coherent light L1 having a dimension d larger than the dimension 31W of the master hologram 31 may be irradiated. When irradiating coherent light L1 having a dimension d larger than the dimension 31W, a mask member 79 having an opening 791 larger than the master hologram 31 is used, or the mask member 79 is omitted. In this case, a replica hologram 310 having approximately the same area as the master hologram 31 is formed in the photosensitive layer 11, just as in the case where coherent light L1 having a dimension d approximately the same as that of the master hologram 31 is irradiated. Note that when coherent light L1 having a dimension d larger than the dimension 31W of the master hologram 31 is irradiated, a portion of the light strays from the master hologram 31. However, since the stray light does not enter the master hologram 31, it does not produce diffracted light. Therefore, interference fringes are not recorded in the photosensitive layer 11 through which the stray light passes. Alternatively, the stray light is absorbed by the light absorption layer 53 and the master light absorption layer 35.

[0082] In the first and second embodiments, coherent light is irradiated from below the exposure unit C, but coherent light may be irradiated from above the exposure unit C (not shown). In this case, the configuration of the exposure unit C in the first and second embodiments is inverted upside down so that coherent light can be irradiated from below the exposure unit C. Furthermore, in the first and second embodiments, the coherent light L1 is irradiated parallel to the normal direction of the master hologram 31, and the diffracted light travels at an acute diffraction angle. However, this is not limited to this example. The coherent light L1 is irradiated at an angle that reproduces the master hologram 31. Furthermore, in the first and second embodiments, coherent light is irradiated onto the workpiece 1 in a substantially horizontal position in the exposure unit C. However, coherent light may be irradiated onto the workpiece 1 in an oblique or vertical position (not shown). The present invention is not limited to the above-described various embodiments and can be modified as appropriate within the intended scope of the present invention.

[0083] A Hologram manufacturing device B Conveying section of manufacturing device C Exposure section of manufacturing device D Light source of manufacturing device L1 Coherent light 11 Photosensitive layer S-1 First row S-2 Second row 3 Master layer 31 Master hologram 41, 42, 43 Light-transmitting plate 51, 53 Light-absorbing layer 61 Laser oscillator 611 First oscillator 612 Second oscillator 613 Third oscillator 62 Reflector 63 Position change mechanism 631 Fixed section 632 Moving section

Claims

1. An apparatus comprising: an exposure unit having a master layer having master holograms arranged in multiple columns in the width direction and multiple rows in a transport direction perpendicular to the width direction; a transport unit that transports an unexposed photosensitive layer and positions the photosensitive layer on the first surface side of the master layer in the exposure unit; and a light source that irradiates the master hologram with coherent light from the first surface side of the photosensitive layer, wherein the coherent light and diffracted light generated from the master hologram by irradiating the coherent light pass through the photosensitive layer to expose it, thereby replicating interference fringes of the master hologram on the photosensitive layer, wherein the transport unit transports the long strip-shaped photosensitive layer a predetermined length in the longitudinal direction and then stops transporting the photosensitive layer; and the light source has a position change mechanism that changes the irradiation position of the coherent light on the master hologram, a position change mechanism for changing the irradiation position between a first position where the coherent light is irradiated onto a plurality of master holograms extending in one row or one column, and a second position where the coherent light is irradiated onto a plurality of master holograms extending in another row or another column.

2. The hologram manufacturing apparatus according to claim 1, wherein the position changing mechanism does not operate until exposure of the photosensitive layer at the first position is complete.

3. The hologram manufacturing device of claim 1, wherein the light source has a coherent light oscillator and a reflector that changes the direction of travel of the coherent light from the oscillator toward the master hologram, and the position changing mechanism moves the reflector between the first position and the second position.

4. The hologram manufacturing apparatus according to claim 3, wherein a plurality of the reflectors are provided corresponding to the plurality of master holograms aligned in the width direction.

5. A hologram manufacturing apparatus as described in claim 3, wherein the oscillator comprises a first oscillator that emits coherent light of a predetermined wavelength, and a second oscillator that emits coherent light of a wavelength different from the wavelength of the coherent light of the first oscillator.

6. The hologram manufacturing device according to claim 3, wherein the position changing mechanism comprises a fixed part, a moving part, and a drive part that moves the moving part relative to the fixed part along the transport direction of the photosensitive layer, and the reflector is provided on the moving part.

7. A hologram manufacturing apparatus as described in claim 1, wherein the exposure unit further has a light-transmitting plate arranged on the first surface side of the master layer, the transport unit transports the photosensitive layer between the first surface of the master layer in the exposure unit and the second surface of the light-transmitting plate, the light source irradiates the master hologram with the coherent light from the first surface side of the light-transmitting plate, and a light-absorbing layer that absorbs the diffracted light is provided on the first surface of the light-transmitting plate in an area other than the area where the coherent light is incident on the master hologram.

8. A hologram manufacturing apparatus as described in claim 1, wherein the exposure unit further has a light-transmitting plate arranged on the first surface side of the master layer, the transport unit transports the photosensitive layer between the first surface of the master layer in the exposure unit and the second surface of the light-transmitting plate, the light source irradiates the master hologram with the coherent light from the first surface side of the light-transmitting plate, and a light-absorbing layer that absorbs the diffracted light is provided on at least one of the end surfaces of the light-transmitting plate on the side along which the diffracted light travels.

9. A method for duplicating interference fringes of the master hologram onto the photosensitive layer, comprising: a transport step of transporting an unexposed photosensitive layer onto a first surface of a master layer having master holograms arranged in a plurality of columns in the width direction and a plurality of rows in a transport direction perpendicular to the width direction; and an exposure step of irradiating coherent light onto the first surface of the photosensitive layer after arranging the photosensitive layer on the first surface of the master layer, wherein the coherent light and diffracted light generated from the master hologram by irradiation with the coherent light are transmitted through the photosensitive layer to expose the photosensitive layer, the method comprising: transporting the photosensitive layer in the length direction by a predetermined length and then stopping transport of the photosensitive layer; A method for manufacturing a hologram, wherein the exposure step involves irradiating the coherent light onto a plurality of master holograms extending in one row or one column to replicate interference fringes corresponding to the master holograms in that row or column in the photosensitive layer, and then irradiating the coherent light onto a plurality of master holograms extending in another row or another column to replicate interference fringes corresponding to the master holograms in that row or column in the photosensitive layer.

10. The method for producing a hologram according to claim 9, wherein the coherent light is a red laser light, a green laser light, a blue laser light, or a composite laser light containing at least two types of light selected from the group consisting of red laser light, green laser light, and blue laser light.

11. A light guide plate having a hologram produced by the method of claim 9 or 10.

12. A light guide plate having a hologram manufactured by the manufacturing apparatus according to any one of claims 1 to 8.

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