Patent Description:
In recent years, optical apparatuses (such as various image projecting devices and imaging devices, for example) including a large number of optical elements have been developed and have become popular. Reduction in size and weight of these optical apparatuses is strongly demanded from the perspectives of wearing on the human body or incorporation into an infrastructure such as various apparatuses or vehicles. In order to meet such a demand, technologies for combining a plurality of optical elements have been proposed as disclosed in Patent Literature <NUM> and Patent Literature <NUM>, for example. Specifically, Patent Literature <NUM> and Patent Literature <NUM> disclose that, by combining an anti-reflection structure in a surface of an optical lens, the optical lens is provided with an anti-reflection property.

Further prior art can be found in <CIT>, <CIT> and <CIT>.

As disclosed in Patent Literature <NUM>, for example, an image projecting device is often provided with a light diffuser panel (defined as a light diffuser sheet in Patent Literature <NUM>) from the perspective of evenly displaying an image. However, a conventional light diffuser panel is separate from an optical lens. Thus, a large space for storing the light diffuser panel and the optical lens is required in the image projecting device, and the image projecting device is increased in size accordingly. Further, in the case where the optical lens and the light diffuser panel are separate from each other, interface reflection occurs at the surface of the optical lens or the surface of the light diffuser panel, and deterioration in light emission quality, such as deterioration in light transmittance or occurrence of ghost due to stray light in an enclosure, occurs in some cases.

Further, a light source unit in which a light source such as LED (light emitting diode) or laser is contained in an optical lens is used in some cases as a light source of an image projecting device. However, a conventional light source unit and another optical element are separate from each other, so that the image projecting device is increased in size. Further, interface reflection occurs at the surface of the light source unit or the surface of the other optical element, and deterioration in light emission quality, such as deterioration in light transmittance or occurrence of ghost, occurs in some cases.

The above-described light diffuser panel and light source unit are used in some cases in other types of optical apparatuses, and problems of size increase and deterioration in light emission quality may also occur in these optical apparatuses. In this manner, there is much more room to improve an optical apparatus from the perspectives of size reduction of the optical apparatus and improvement of the light emission quality.

Therefore, the present invention was made in view of the above-described problems, and the present invention has an object to reduce an optical apparatus in size and to improve the light emission quality.

According to the present invention as defined in claim <NUM>, there is provided a light source unit including a light source, an optical base material containing the light source, and a resin layer provided on a light emitting surface of the optical base material. A micro concave-convex structure is formed in a surface of the resin layer.

Herein, the micro concave-convex structure may include at least one of a moth-eye structure, a light diffusing structure, a microlens array structure, and a diffraction grating structure.

In addition, the micro concave-convex structure may include the moth-eye structure, and an average interval between micro concavities or micro convexities constituting the micro concave-convex structure may be <NUM> to <NUM>. In addition, a height difference between one of micro concavities and one of micro convexities adjacent to each other may be <NUM> to <NUM>.

According to another aspect of the present invention, there is provided an optical unit as defined in claim <NUM>, including the above-described light source unit,.

According to another aspect of the present invention, there is provided a light irradiation device including the above-described optical unit.

According to another aspect of the present invention, there is provided an image display device including the above-described light irradiation device.

According to another aspect of the present invention, there is provided a method for manufacturing a light source unit, as defined in claim <NUM>, including a first step of preparing an optical base material having a curved surface and containing a light source, a second step of forming an uncured resin layer on the curved surface of the optical base material, a third step of preparing a flexible master having an inverted structure of a micro concave-convex structure formed in a surface, the flexible master having flexibility, a fourth step of bringing the flexible master into proximity to the uncured resin layer, a fifth step of pressing the inverted structure of the flexible master against the uncured resin layer while applying a printing pressure to the flexible master to deform the flexible master, and a sixth step of curing the uncured resin layer in a state where the inverted structure of the flexible master is pressed against the uncured resin layer to form a resin layer on the curved surface of the optical base material.

In addition, there is provided a method for manufacturing a light source unit, including a first step of preparing an optical base material having a curved surface, a second step of forming an uncured resin layer on the curved surface of the optical base material, a third step of preparing a flexible master having an inverted structure of a micro concave-convex structure formed in a surface, the flexible master having flexibility, a fourth step of bringing the flexible master into proximity to the uncured resin layer, a fifth step of pressing the inverted structure of the flexible master against the uncured resin layer while applying a printing pressure to the flexible master to deform the flexible master, a sixth step of curing the uncured resin layer in a state where the inverted structure of the flexible master is pressed against the uncured resin layer to form a resin layer on the curved surface of the optical base material, and a seventh step of placing, on a light source, the optical base material on which the resin layer has been formed.

According to the present invention, as described above, an optical apparatus can be reduced in size, and the light emission quality can be improved.

Hereinafter, referring to the appended drawings, preferred embodiments of the present invention will be described in detail. It should be noted that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation thereof is omitted.

First, a configuration of a resin laminated optical body <NUM> according to an embodiment of the present invention will be described on the basis of <FIG>. As illustrated in <FIG>, the resin laminated optical body <NUM> includes an optical base material <NUM> and a resin layer <NUM>. The optical base material <NUM> is a convex lens, and has a convex curved surface <NUM>. Note that, in the example of <FIG>, the optical base material <NUM> is a plano-convex lens (convex lens having a flat surface on one side), but may be a double-convex lens (convex lens having convex surfaces on both sides). Alternatively, the optical base material <NUM> may be another type of lens such as, for example, a concave lens or Fresnel lens. The shape of the optical base material <NUM> is not limited to those described above, but may have an aspherical shape, a round shape, a square shape, an asymmetric shape, or the like, for example. The optical base material <NUM> may be a mirror.

The material of the optical base material <NUM> is not particularly restricted, but may be a material used for an optical lens or optical mirror. Examples of the material of the optical base material <NUM> include polycarbonate, acrylate, cycloolefin polymers, cycloolefin copolymers, polypropylene, glass, and the like. The material of the optical base material <NUM> may be selected as appropriate in accordance with the use and the like of the resin laminated optical body <NUM>. Note that, in a case of using the optical base material <NUM> as an optical mirror, mirror surface processing (such as evaporation of a metal film or dielectric, for example) may be performed on the curved surface <NUM>.

The curved surface <NUM> may be subjected to various types of pretreatment (treatment before laminating the resin layer <NUM> on the curved surface <NUM>) in order to improve adhesion between the curved surface <NUM> and the resin layer <NUM>. Examples of such pretreatment include corona treatment, excimer treatment, UV ozone treatment, heat treatment, flame treatment (treatment of applying flame to the curved surface <NUM>), solvent cleaning, primer applying treatment, and the like.

The resin layer <NUM> is provided on the curved surface <NUM> of the optical base material <NUM>. The curved surface <NUM> of the optical base material <NUM> and the resin layer <NUM> are in close contact, and the optical base material <NUM> and the resin layer <NUM> are integrated with each other. A micro concave-convex structure <NUM> is formed in a surface <NUM> of the resin layer <NUM> (the surface opposite to the optical base material <NUM>), as illustrated in <FIG>. The micro concave-convex structure <NUM> includes a large number of micro convexities 50a and a large number of micro concavities 50b. The resin layer <NUM> is provided with optical properties derived from this micro concave-convex structure <NUM>. Various optical properties can be provided for the resin layer <NUM> by changing the shape of the micro concave-convex structure <NUM>. In particular, in the present embodiment, the micro concave-convex structure <NUM> is a light diffusing structure. Specifically, the shape of the micro convexities 50a or the micro concavities 50b is adjusted such that light passing through the optical base material <NUM> and arrived at the micro concave-convex structure <NUM> is diffused and radiated to the outside. Therefore, the resin layer <NUM> is provided with a light diffusing property.

An average interval between two adjacent micro concavities 50b, 50b or an average interval between two adjacent micro convexities 50a, 50a preferably is <NUM> to <NUM>. Further, a height difference between one of the micro concavities 50b and one of the micro convexities 50a adjacent to each other preferably is <NUM> to <NUM>. In a case where at least one (preferably both) of these conditions is satisfied, the light diffusing property is further increased. The micro concave-convex structure <NUM> may be a concave-convex structure in which the above-described average interval is less than or equal to <NUM>, for example, and the above-described height difference is less than or equal to <NUM>, for example.

Herein, the shape of the micro concave-convex structure <NUM> is observed using a scanning electron microscope (SEM) or an atomic force microscope (AFM), for example. Then, the above-described average interval or height difference is measured on the basis of an observation result. For example, the average interval between the micro concavities 50b, 50b is measured by the following method. That is, the cross section at the center of the resin laminated optical body <NUM> (the cross section passing through and being parallel to the optical axis) is observed. Then, the distance between the central points (the central points of bottom surfaces) of adjacent micro concavities 50b is measured. Then, some distances between the central points are measured, and their arithmetic mean value may be determined as the average interval between the micro concavities 50b, 50b. The average interval between the micro convexities 50a, 50a is also measured by a similar method. That is, the distance between the peaks (the central points of upper ends) of adjacent micro convexities 50a is measured. Then, some peak-to-peak distances are measured, and their arithmetic mean value may be determined as the average interval between the micro convexities 50a, 50a. A height difference between one of the micro concavities 50b and one of the micro convexities 50a adjacent to each other is the distance between the central point of the bottom surface of the micro concavity 50b and the peak of the micro convexity 50a (the distance in the thickness direction of the resin layer <NUM>).

The thickness of the resin layer <NUM> is not particularly restricted, but is desirably less than or equal to <NUM>, for example. If the resin layer <NUM> is extremely thick, film stresses are accumulated because of cure shrinkage of resin during light (UV) curing, and poor contact may occur between the optical base material <NUM> and the resin layer <NUM>.

Herein, as described above, the surface <NUM> of the resin layer <NUM> is not flat since the micro concave-convex structure <NUM> is formed therein. Thus, the thickness of the resin layer <NUM> is measured by the following method, for example. That is, the cross section at the center of the resin laminated optical body <NUM> (the cross section passing through and being parallel to the optical axis) is observed using various types of three-dimensional measuring equipment (for example, "Three-dimensional measuring equipment UA3P" made by Panasonic Corporation). Then, the obtained curve of the surface <NUM> is subjected to curve fitting by the least squares method. The cross section at the center of the optical base material <NUM> (that is, before processing) (the cross section passing through and being parallel to the optical axis) is observed, and an obtained image is compared with the cross section at the center of the resin laminated optical body <NUM> to specify a region of the resin layer <NUM>. Then, the distance from the curve of the surface <NUM> obtained by curve fitting described above to the curve of the curved surface <NUM> is determined as the thickness of the resin layer <NUM>. In examples which will be described later, the thickness of the resin layer <NUM> was measured by this method. Note that the thickness was determined as the arithmetic mean value of values measured at some measurement points. For the measurement, "Three-dimensional measuring equipment UA3P" made by Panasonic Corporation was used.

In this manner, in the resin laminated optical body <NUM> according to the present embodiment, the resin layer <NUM> having the light diffusing property and the optical base material <NUM> are integrated with each other. Therefore, by applying the resin laminated optical body <NUM> to an optical apparatus, the optical apparatus can be reduced in size. Furthermore, as compared with the case of arranging a substrate having the light diffusing property and an unprocessed optical base material <NUM> as separate components, the light transmittance is improved and ghost is prevented from occurring since an interface at which reflection may occur is reduced by integrating these components in the present embodiment. That is, the light emission quality is improved.

Herein, some regions of the surface <NUM> of the resin layer <NUM> may be provided with the light diffusing property, and other regions may be provided with a different optical property. That is, the type of the micro concave-convex structure <NUM> may be changed per region of the surface <NUM>. Examples of the micro concave-convex structure <NUM> other than the light diffusing structure include a moth-eye structure, light diffusing structure, microlens array structure, diffraction grating structure, or the like. That is, any one or more types of these structures may be mixed in the surface <NUM> of the resin layer <NUM> in addition to the light diffusing structure.

In a case where the micro concave-convex structure <NUM> is a moth-eye structure, the micro convexities 50a or the micro concavities 50b are arrayed on the surface <NUM> at an average cycle less than or equal to a visible light wavelength (the average cycle herein is synonymous with the average interval described above). Accordingly, external light is restrained from reflecting off the surface <NUM>. Furthermore, the average interval between the micro concavities 50b, 50b or the micro convexities 50a, 50a constituting the micro concave-convex structure preferably is <NUM> to <NUM>, and the height difference between one of the micro concavities 50b and one of the micro convexities 50a adjacent to each other preferably is <NUM> to <NUM>. In this case, reflection of external light is restrained more effectively. Therefore, in the case where the micro concave-convex structure <NUM> is a moth-eye structure, the resin layer <NUM> is provided with an anti-reflection property. The micro concave-convex structure <NUM> as the moth-eye structure may be a concave-convex structure in which the above-described average interval is less than or equal to <NUM>, for example, and the above-described height difference is less than or equal to <NUM>, for example.

In a case where the micro concave-convex structure <NUM> is a microlens array structure, the micro convexities 50a or the micro concavities 50b are micron-order microlenses. In a case where the micro concave-convex structure <NUM> is a diffraction grating structure, the micro convexities 50a or the micro concavities 50b have the shape of diffraction grating. The micro concave-convex structure <NUM> other than the light diffusing structure is not limited to the above-described examples. In addition, the micro concave-convex structure <NUM> having the same type of pattern but adjusted to have different optical properties may be mixed or arrayed in the surface <NUM> of the resin layer <NUM>. For example, the micro concave-convex structure <NUM> may be designed such that some regions and other regions among regions where the light diffusing structure is formed have different light diffusing properties. In this case, the average interval or height difference described above should only be changed per region.

The resin layer <NUM> includes a cured curing resin. The cured curing resin preferably is transparent. The curing resin includes a polymerizable compound and a curing initiator. The polymerizable compound is a resin that is cured by the curing initiator. Examples of the polymerizable compound include a polymerizable epoxy compound or a polymerizable acrylic compound. A polymerizable epoxy compound is a monomer, oligomer, or prepolymer having one or multiple epoxy groups in the molecule. Examples of polymerizable epoxy compounds include various bisphenol epoxy resins (such as bisphenol A and F), novolac epoxy resin, various modified epoxy resins such as rubber and urethane, naphthalene epoxy resin, biphenyl epoxy resin, phenol novolac epoxy resin, stilbene epoxy resin, triphenol methane epoxy resin, dicyclopentadiene epoxy resin, triphenyl methane epoxy resin, and prepolymers of the above.

A polymerizable acrylic compound is a monomer, oligomer, or prepolymer having one or multiple acrylic groups in the molecule. Herein, monomers are further classified into monofunctional monomers having one acrylic group in the molecule, bifunctional monomers having two acrylic groups in the molecule, and multifunctional monomers having three or more acrylic groups in the molecule.

Examples of "monofunctional monomers" include carboxylic acids (acrylic acids or the like), hydroxy monomers (<NUM>-hydroxyethyl acrylate, <NUM>-hydroxypropyl acrylate, <NUM>-hydroxybutyl acrylate), alkyl or alicyclic monomers (isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate), other functional monomers (<NUM>-methoxyethyl acrylate, methoxyethylene glycol acrylate, <NUM>-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, N,N-dimethylamino ethyl acrylate, N,N-dimethylamino propyl acrylamide, N,N-dimethyl acrylamide, acryloyl morpholine, N-isopropyl acrylamide, N,N-diethyl acrylamide, N-vinylpyrrolidone, <NUM>-(perfluorooctyl)ethyl acrylate, <NUM>-perfluorohexyl-<NUM>-hydroxypropyl acrylate, <NUM>-perfluorooctyl-<NUM>-hydroxypropyl-acrylate, <NUM>-(perfluorodecyl)ethyl-acrylate, <NUM>-(perfluoro-<NUM>-methylbutyl)ethyl acrylate), <NUM>,<NUM>,<NUM>-tribromophenol acrylate, <NUM>,<NUM>,<NUM>-tribromophenol methacrylate, <NUM>-(<NUM>,<NUM>,<NUM>-tribromophenoxy)ethyl acrylate), and <NUM>-ethylhexyl acrylate.

Examples of "bifunctional monomers" include tri(propylene glycol) di-acrylate, trimethylolpropane-diaryl ether, and urethane acrylate.

Examples of "multifunctional monomers" include trimethylolpropane tri-acrylate, dipentaerythritol penta- and hexa-acrylate, and ditrimethylolpropane tetra-acylate.

Examples other than the polymerizable acrylic compounds listed above include acrylmorpholine, glycerol acrylate, polyether acrylates, N-vinylformamide, N-vinylcaprolactone, ethoxy diethylene glycol acrylate, methoxy triethylene glycol acrylate, polyethylene glycol acrylate, ethoxylated trimethylolpropane tri-acrylate, ethoxylated bisphenol A di-acrylate, aliphatic urethane oligomers, and polyester oligomers.

By adjusting the type, compounding ratio, and the like of constitutional units of the curing resin, that is, a monomer, an oligomer, or a prepolymer, the properties of the resin layer <NUM>, such as the refractive index and viscosity, for example, can be adjusted.

The curing initiator is a material that cures the curing resin. Examples of the curing initiator include thermal curing initiators and light-curing initiators, for example. The curing initiator may also be one that cures by some kind of energy beam other than heat or light (for example, an electron beam) or the like. In the case where the curing initiator is a thermal curing initiator, the curing resin is a thermosetting resin, whereas in the case where the curing initiator is a light-curing initiator, the curing resin is a light-curing resin.

Herein, from the perspective of processability of the resin layer <NUM>, the curing initiator preferably is an ultraviolet-curing initiator. An ultraviolet-curing initiator is a type of light-curing initiator. Examples of ultraviolet-curing initiators include <NUM>,<NUM>-dimethoxy-<NUM>,<NUM>-diphenylethane-<NUM>-one, <NUM>-hydroxy-cyclohexyl phenyl ketone, and <NUM>-hydroxy-<NUM>-methyl-<NUM>-phenyl propane-<NUM>-one. Consequently, the curing resin preferably is an ultraviolet-curing resin. From the perspective of transparency, the curing resin more preferably is an ultraviolet-curing acrylic resin. The curing resin can be selected and adjusted as appropriate in accordance with optical properties of materials constituting the optical base material <NUM> and an optical design of the device.

Next, various variations of the resin laminated optical body <NUM> will be described on the basis of <FIG>. In the variation illustrated in <FIG>, the optical base material <NUM> is a plano-concave lens (concave lens having a flat surface on one side). The resin layer <NUM> is formed on the curved surface <NUM> of the optical base material <NUM>, and the resin layer <NUM> is in close contact with the curved surface <NUM> of the optical base material <NUM>. The micro concave-convex structure <NUM> described above is formed in the resin layer <NUM>.

In the variation illustrated in <FIG>, the resin layers <NUM> are formed on both the front and rear surfaces of the optical base material <NUM> illustrated in <FIG>. The micro concave-convex structure <NUM> described above is formed in each of the resin layers <NUM>. These micro concave-convex structures <NUM> may be of the same type, or may be different from each other. For example, the micro concave-convex structures <NUM> on both the front and rear surfaces may be light diffusing structures. The micro concave-convex structure <NUM> on the front surface (herein, the curved surface <NUM>) side may be a light diffusing structure, and the micro concave-convex structure <NUM> on the rear surface side may be a moth-eye structure. Conversely, the micro concave-convex structure <NUM> on the front surface side may be a moth-eye structure, and the micro concave-convex structure <NUM> on the rear surface side may be a light diffusing structure. That is, the micro concave-convex structures <NUM> formed in the resin laminated optical body <NUM> should only include a light diffusing structure. The same also applies to the following respective variations.

In the variation illustrated in <FIG>, the resin layers <NUM> are formed on both the front and rear surfaces of the optical base material <NUM> illustrated in <FIG>. The micro concave-convex structure <NUM> described above is formed in each of the resin layers <NUM>. The micro concave-convex structures <NUM> may be of the same type, or may be different from each other.

In the variation illustrated in <FIG>, the optical base material <NUM> is a double-convex lens (convex lens having convex surfaces on both the front and rear surfaces), and the resin layers <NUM> are formed on both the front and rear surfaces. The micro concave-convex structure <NUM> described above is formed in each of the resin layers <NUM>. The micro concave-convex structures <NUM> may be of the same type, or may be different from each other.

In the variation illustrated in <FIG>, the optical base material <NUM> is a double-concave lens (concave lens having concave surfaces on both the front and rear surfaces), the resin layers <NUM> are formed on both the front and rear surfaces. The micro concave-convex structure <NUM> described above is formed in each of the resin layers <NUM>. The micro concave-convex structures <NUM> may be of the same type, or may be different from each other.

In the variation illustrated in <FIG>, the front surface of the optical base material <NUM> is a convex surface, and the rear surface is a concave surface. Further, the resin layers <NUM> are formed on both the front and rear surfaces of the optical base material <NUM>. The micro concave-convex structure <NUM> described above is formed in each of the resin layers <NUM>. The micro concave-convex structures <NUM> may be of the same type, or may be different from each other.

Obviously, the resin laminated optical body <NUM> according to the present embodiment is not limited to the example of <FIG> and the above-described variations of <FIG>. For example, in <FIG>, the resin layer <NUM> on the front surface side or the rear surface side may be omitted.

Next, a configuration of the light source unit <NUM> according to the present embodiment will be described on the basis of <FIG> and <FIG>. As illustrated in <FIG>, the light source unit <NUM> includes a light source <NUM>, an optical base material <NUM>, and a resin layer <NUM>. The light source <NUM> is a device or member that emits light. The type of the light source <NUM> is not particularly limited, and may be a light emitting diode (LED), for example, or may be a laser light source, or the like. Although three light sources <NUM> are depicted in <FIG>, the number of the light sources <NUM> included in the light source unit <NUM> is adjusted as appropriate according to the use and the like of the light source unit <NUM>.

Herein, the light source <NUM> is contained in the optical base material <NUM>. The light source <NUM> may be integrated with the optical base material <NUM>, or may be separate from the optical base material <NUM>. The light source unit <NUM> outputs light emitted from the light source <NUM> to the outside through an interface 32a. A curved surface <NUM> is formed on the interface 32a, and the resin layer <NUM> is laminated along the curved surface <NUM>. In the example of <FIG>, the curved surface <NUM> is a convex surface, but may be a concave surface. Therefore, the optical base material <NUM> functions as a lens for the light source <NUM>. The curved surface <NUM> may be omitted. The material of the optical base material <NUM> is not particularly restricted, but may be a material similar to that of the optical base material <NUM> described above, for example.

The interface 32a may be subjected to various types of pretreatment (treatment before laminating the resin layer <NUM> on the light emitting surface 32a) in order to improve adhesion to the resin layer <NUM>. Examples of such pretreatment include corona treatment, excimer treatment, UV ozone treatment, heat treatment, flame treatment (treatment of applying flame to the curved surface <NUM>), solvent cleaning, primer applying treatment, and the like.

The resin layer <NUM> is provided on the interface 32a of the optical base material <NUM>. The micro concave-convex structure <NUM> illustrated in <FIG> is formed in a surface <NUM> of the resin layer <NUM>. The detailed description of the micro concave-convex structure <NUM> is as given above. The resin layer <NUM> is provided with an optical property derived from this micro concave-convex structure <NUM>. By changing the shape of the micro concave-convex structure <NUM>, various optical properties can be provided for the resin layer <NUM>.

Herein, the resin layer <NUM> is provided with an arbitrary optical property. That is, the micro concave-convex structure <NUM> may be a moth-eye structure, light diffusing structure, microlens array structure, or diffraction grating structure, for example. That is, the optical property of the resin layer <NUM> is not necessarily limited to the light diffusing property. Any one or more types of these structures may be mixed in the surface <NUM> of the resin layer <NUM>. In addition, the shape of the micro concave-convex structure <NUM> may be adjusted to have the same type of pattern (the light diffusing structure, for example) but have different optical properties. Materials constituting the resin layer <NUM> and the thickness may be similar to those of the resin layer <NUM>, for example. The thickness of the resin layer <NUM> is measured similarly to the resin layer <NUM>.

In this manner, in the present embodiment, the light source unit <NUM> and the resin layer <NUM> having various optical properties are integrated with each other. Therefore, by applying the light source unit <NUM> to an optical apparatus, the optical apparatus can be reduced in size. Furthermore, by forming a moth-eye structure in the surface of the light source unit <NUM>, for example, reflection off the interface 32a is restrained, the light transmittance is improved, and ghost is prevented from occurring. That is, the light emission quality is improved.

The resin laminated optical body <NUM> can be produced by what is called an imprinting method. Hereinafter, a method for manufacturing the resin laminated optical body <NUM> will be described in detail on the basis of <FIG>. Note that in the example of <FIG>, the optical base material <NUM> is a double-convex lens.

First, the optical base material <NUM> described above is prepared. For example, the optical base material <NUM> may be manufactured by a publicly-known molding method, or the optical base material <NUM> which is commercially available may be obtained.

Then, as illustrated in <FIG>, the optical base material <NUM> is set on an optical base material fixing jig <NUM>. Then, the curved surface <NUM> (herein, the convex surface on one side) of the optical base material <NUM> is coated with an uncured curing resin using an applicator device <NUM>. Accordingly, an uncured resin layer 20a is formed on the curved surface <NUM> of the optical base material <NUM>. The type of the applicator device <NUM> is not particularly limited, and may be a spin coater, a dispenser, an ink jet device, or the like, for example. The type of the applicator device <NUM> should only be selected depending on the properties or the like of the uncured resin layer 20a. In order to adjust adhesion of the uncured resin layer 20a to the optical base material <NUM>, viscosity of the uncured resin layer 20a, or the like, the optical base material <NUM> may be heated before or during coating processing. In addition, the uncured resin layer 20a may be subjected to heat treatment after coating processing depending on the type of the uncured resin layer 20a. Note that the applicator device <NUM> may be incorporated into a chamber device <NUM> which will be described later, or may be separate from the chamber device <NUM>.

In a third step, a flexible master <NUM> illustrated in <FIG> is prepared. Herein, the flexible master <NUM> is a film having flexibility, and an inverted structure (hereinafter, also referred to as an "inverted concave-convex structure <NUM>") of the micro concave-convex structure <NUM> is formed in the surface thereof. The flexible master <NUM> may also be referred to as a soft mold. The inverted concave-convex structure <NUM> is illustrated in <FIG>. A method for manufacturing the flexible master <NUM> will be described later. The third step should only be performed at least before a fourth step which will be described later is performed.

The fourth step includes a step of setting the optical base material and the flexible master, and an optical base material approaching step.

As illustrated in <FIG>, the optical base material fixing jig <NUM> and the optical base material <NUM> are set in the chamber device <NUM>. Herein, the chamber device <NUM> is a hollow device, and has an upper chamber box <NUM>, a lower chamber box <NUM>, a film fixing jig <NUM>, and a movable table <NUM>. The upper chamber box <NUM> is a box-shaped member which is open downward, and the lower chamber box <NUM> is a box-shaped member which is open upward.

A vacuum pump or pneumatic pump is connected to the upper chamber box <NUM> and the lower chamber box <NUM>, and can bring the inner space of each of them into a negative pressure or positive pressure state. Herein, when bringing the space in each of the chamber boxes into the positive pressure state, any type of fluid is introduced into the space in each of the chamber boxes. Herein, examples of the fluid include gas such as air, but may be a liquid. A specific value of a pressure in each of the chamber boxes and a time for holding such a pressure can be adjusted arbitrarily. In addition, a UV irradiation device not shown is provided in the upper chamber box <NUM>. The UV irradiation device may be provided in the lower chamber box <NUM>. The UV intensity and irradiation time can be adjusted arbitrarily. Note that this example is premised on the uncured resin layer 20a being made of an ultraviolet-curing resin, whilst in a case where the uncured resin layer 20a is made of another type of curing resin, a device for curing the curing resin should only be provided in the upper chamber box <NUM> or the lower chamber box <NUM>. In addition, each of the chamber boxes may be provided with a heating device. The film fixing jig <NUM> is a jig for fixing the flexible master <NUM> which will be described later to the open face of the lower chamber box <NUM>. The movable table <NUM> is arranged in the lower chamber box <NUM>, and can be moved vertically by a driving device not shown.

More specifically, the optical base material <NUM> is set on the movable table <NUM> together with the optical base material fixing jig <NUM>. Then, the flexible master <NUM> is fixed to the film fixing jig <NUM>. The open face of the lower chamber box <NUM> is closed by the flexible master <NUM>. The flexible master <NUM> is fixed to the film fixing jig <NUM> in such a manner that the surface in which the inverted concave-convex structure <NUM> is formed faces the optical base material <NUM> side. In the illustrated example, the lower surface of the flexible master <NUM> corresponds to the surface in which the inverted concave-convex structure <NUM> is formed.

Then, as illustrated in <FIG>, the upper chamber box <NUM> and the lower chamber box <NUM> are coupled to each other. Accordingly, the space in the chamber device <NUM> is sealed. On this occasion, the temperature in the chamber device <NUM> may be raised. Then, the space in the chamber device <NUM> is evacuated. Then, the movable table <NUM> is lifted to bring the flexible master <NUM> and the optical base material <NUM> into proximity to each other. The distance between the flexible master <NUM> and the optical base material <NUM> should only be adjusted as appropriate in accordance with the shape or the like of the optical base material <NUM>. Arrows in <FIG> indicate the direction in which the movable table <NUM> is moved.

Then, a fluid is introduced into the upper chamber box <NUM> to bring the space in the upper chamber box <NUM> into the positive pressure state. A printing pressure is thereby applied to the flexible master <NUM>. Arrows in <FIG> indicate the direction of the printing pressure. Through this step, the inverted concave-convex structure <NUM> of the flexible master <NUM> is pressed against the uncured resin layer 20a while deforming the flexible master <NUM>. Accordingly, the uncured resin layer 20a spreads across the curved surface <NUM> (the convex surface on one side), and the uncured resin layer 20a enters between micro-convexities of the inverted concave-convex structure <NUM>. Herein, it is preferable not to leave a gap between the uncured resin layer 20a and the flexible master <NUM> whenever possible. This is because, if a gap is left, a phenomenon such as entry of air bubbles or insufficient transfer of the inverted concave-convex structure <NUM> to the resin layer <NUM> is likely to occur.

Then, the uncured resin layer 20a is cured in this state. Specifically, by irradiating the uncured resin layer 20a with ultraviolet rays, the uncured resin layer 20a made of an ultraviolet-curing resin is cured. Accordingly, the uncured resin layer 20a becomes the resin layer <NUM>, and the inverted concave-convex structure <NUM> is transferred to the surface of the resin layer <NUM>. That is, an inverted structure of the inverted concave-convex structure <NUM>, that is, the micro concave-convex structure <NUM>, is formed in the surface <NUM> of the resin layer <NUM>. Through the above steps, the resin laminated optical body <NUM> is produced.

Then, as illustrated in <FIG>, the movable table <NUM> is moved down to separate the resin laminated optical body <NUM> from the flexible master <NUM>. Note that, in this step, a separation assisting step for promoting separation of the flexible master <NUM> and the resin laminated optical body <NUM> may be performed. Examples of such a separation assisting step include inserting a blade between the flexible master <NUM> and the resin laminated optical body <NUM>, blowing gas such as air between the flexible master <NUM> and the resin laminated optical body <NUM>, and the like.

Thereafter, the space in the chamber device <NUM> is brought into an atmospheric pressure state, and the upper chamber box <NUM> is detached. Then, the flexible master <NUM> and the resin laminated optical body <NUM> are taken out from the lower chamber box <NUM>. Note that further ultraviolet irradiation treatment may be performed for the purpose of promoting curing of the resin layer <NUM>, or heat treatment may be performed for the purpose of relieving stress in the resin layer <NUM>.

Through the above steps, the resin layer <NUM> can be formed on the curved surface <NUM> on one side of the optical base material <NUM>. The resin layer <NUM> may also be formed on the curved surface on the opposite side according to necessity through steps similar to those described above.

Note that, in a case where the optical base material <NUM> is a concave lens, the resin laminated optical body <NUM> can also be produced through steps similar to those described above. An overview of steps is illustrated in <FIG> and <FIG>. As illustrated in <FIG>, the uncured resin layer 20a is formed on the curved surface <NUM> of the optical base material <NUM>. Then, the optical base material <NUM> and the flexible master <NUM> are set in the chamber device <NUM>. Then, the flexible master <NUM> and the optical base material <NUM> are brought closer to each other. Then, as illustrated in <FIG>, a printing pressure is applied to the flexible master <NUM>. An arrow in <FIG> indicates the direction of the printing pressure. Through this step, the inverted concave-convex structure <NUM> of the flexible master <NUM> is pressed against the uncured resin layer 20a while deforming the flexible master <NUM>. Accordingly, the uncured resin layer 20a spreads across the curved surface <NUM>, and the uncured resin layer 20a enters between the micro-convexities of the inverted concave-convex structure <NUM>. Herein, it is preferable not to leave a gap between the uncured resin layer 20a and the flexible master <NUM> whenever possible. In this state, the uncured resin layer 20a is cured. Specifically, the uncured resin layer 20a is irradiated with ultraviolet rays. Accordingly, the uncured resin layer 20a becomes the resin layer <NUM>, and the inverted concave-convex structure <NUM> is transferred to the surface <NUM> of the resin layer <NUM>. As a result, an inverted structure of the inverted concave-convex structure <NUM>, that is, the micro concave-convex structure <NUM>, is formed in the surface <NUM> of the resin layer <NUM>. Through the above steps, the resin laminated optical body <NUM> is produced.

Then, the resin laminated optical body <NUM> is separated from the flexible master <NUM>, and the flexible master <NUM> and the resin laminated optical body <NUM> are taken out from the chamber device <NUM>.

Through the above steps, the resin layer <NUM> can be formed on the curved surface <NUM> on one side of the optical base material <NUM>. The resin layer <NUM> may also be formed on the curved surface on the opposite side according to necessity through steps similar to those described above. According to the method for manufacturing the resin laminated optical body <NUM> described above, the resin layer <NUM> can be easily formed on the curved surface <NUM> of the optical base material <NUM>.

Next, a method for manufacturing the light source unit <NUM> will be described. The light source unit <NUM> is also produced by a manufacturing method which is similar to that of the resin laminated optical body <NUM>, but differs from the method for manufacturing the resin laminated structure <NUM> in that a step of having the light source <NUM> contained in the light source unit <NUM> is added. Herein, examples of a method of having the light source <NUM> contained in the light source unit <NUM> include a method of having the light source <NUM> contained in the optical base material <NUM> in advance. In this method, by directly charging resin onto the light source <NUM> by forming such as molding, the light source <NUM> is embedded into the optical base material <NUM>. This optical base material <NUM> is subjected to the second and subsequent steps described above to produce the light source unit <NUM>. Another method for having the light source <NUM> contained in the light source unit <NUM> is the following method. That is, the optical base material <NUM> separate from the light source <NUM> is subjected to the first step to the separation step described above to form the resin layer <NUM> on the optical base material <NUM>. Then, the optical base material <NUM> with the resin layer <NUM> formed thereon is placed on the light source <NUM>. The light source unit <NUM> including the light source <NUM> is thereby produced. According to the method for manufacturing the light source unit <NUM> as described above, the resin layer <NUM> can easily be formed on the curved surface <NUM> of the optical base material <NUM>.

Next, a detailed configuration of the flexible master <NUM> and a method for manufacturing the same will be described. As illustrated in <FIG>, the flexible master <NUM> includes a flexible base material <NUM>, and a resin layer <NUM> formed on a surface of the flexible base material <NUM>. The flexible base material <NUM> is a planar base material having flexibility. Examples of the material constituting the flexible base material <NUM> include acrylic resins (such as poly methyl methacrylate), polycarbonate, polyethylene terephthalate (PET; note that the properties of PET are not particularly specified, and the PET may be amorphous or stretched), triacetyl cellulose (TAC), polyethylene, polypropylene, polycarbonate, cycloolefin polymers, cycloolefin copolymers, vinyl chloride, and the like.

The resin layer <NUM> includes a curing resin. The type of curing resin is not particularly restricted, and may be a curing resin similar to the curing resin constituting the resin layer <NUM>, for example. The inverted concave-convex structure <NUM> is formed in the resin layer <NUM>. The inverted concave-convex structure <NUM> includes large numbers of micro-convexities 430a and micro-concavities 430b.

Next, the method for manufacturing the flexible master <NUM> will be described. The method for manufacturing the flexible master <NUM> includes a first master producing step, second master producing step, and first master producing step. In the first master producing step, a transfer mold having an inverted structure of the inverted concave-convex structure <NUM> is produced. In the second master producing step, an uncured resin layer <NUM> is formed on the surface of the flexible base material <NUM>. In the third master producing step, the uncured resin layer <NUM> is cured, and the concave-convex structure of the transfer mold is transferred to the resin layer <NUM> after curing.

The first master producing step is a step of producing a transfer mold having the inverted structure of the inverted concave-convex structure <NUM>. The transfer mold is a master <NUM> illustrated in <FIG>, for example.

The configuration of the master <NUM> will now be described. The master <NUM> has a cylindrical shape. The master <NUM> may also have a round columnar shape, or another shape (for example, a planar shape). However, in the case where the master <NUM> has a round columnar or cylindrical shape, a concave-convex structure (that is, a master concave-convex structure) <NUM> of the master <NUM> can be transferred seamlessly to a resin base material or the like by a roll-to-roll method. The inverted concave-convex structure <NUM> can thereby be formed in the surface of the flexible base material <NUM> with high production efficiency. From such a perspective, the shape of the master <NUM> preferably has a cylindrical shape or a round columnar shape.

The master <NUM> includes a master base material <NUM>, and the master concave-convex structure <NUM> formed in the circumferential surface of the master base material <NUM>. The master base material <NUM> is a glass body, for example, and specifically is formed from quartz glass. However, the master base material <NUM> is not particularly limited insofar as the SiO<NUM> purity is high, and may also be formed from a material such as fused quartz glass or synthetic quartz glass. The master base material <NUM> may also be a laminate of the above materials on a metal matrix, or a metal matrix (for example, Cu, Ni, Cr, Al). The shape of the master base material <NUM> is a cylindrical shape, but may also be a round columnar shape, or another shape. However, as described above, the master base material <NUM> preferably has a cylindrical shape or a round columnar shape. The master concave-convex structure <NUM> has an inverted structure of the inverted concave-convex structure <NUM>.

Next, a method for manufacturing the master <NUM> will be described. First, a base material resist layer is formed (deposited) on the master base material <NUM>. Herein, the resist material constituting the base material resist layer is not particularly limited, and may be either an organic resist material or an inorganic resist material. Examples of organic resist materials include novolac-type resist and chemically-amplified resist. In addition, examples of inorganic resist materials include metallic oxides including one or multiple types of transition metals such as tungsten (W) or molybdenum (Mo). Other examples of inorganic resist materials include Cr, Au, and the like. However, in order to conduct thermal reaction lithography, the base material resist layer preferably is formed from a thermo-reactive resist including a metallic oxide.

In the case of using an organic resist material for the base material resist layer, the base material resist layer may be formed on the master base material <NUM> by using a process such as spin coating, slit coating, dip coating, spray coating, or screen printing. Alternatively, in the case of using an inorganic resist material for the base material resist layer, the base material resist layer may be formed using sputtering. An organic resist material and an inorganic resist material may also be used together.

Next, by exposing part of the base material resist layer with an exposure device <NUM> (see <FIG>), a latent image is formed on the base material resist layer. Specifically, the exposure device <NUM> modulates laser light 200A, and irradiates the base material resist layer with the laser light 200A. Consequently, part of the base material resist layer irradiated with the laser light 200A denatures, and thus a latent image corresponding to the master concave-convex structure <NUM> can be formed in the base material resist layer.

Next, by dripping a developing solution onto the base material resist layer in which the latent image is formed, the base material resist layer is developed. Accordingly, a concave-convex structure is formed in the base material resist layer. Subsequently, by etching the master base material <NUM> and the base material resist layer using the base material resist layer as a mask, the master concave-convex structure <NUM> is formed on the master base material <NUM>. Note that although the etching method is not particularly limited, dry etching that is vertically anisotropic is preferable. For example, reactive ion etching (RIE) is preferable. Through the above steps, the master <NUM> is produced. The etching may be wet etching.

Next, the configuration of the exposure device <NUM> will be described on the basis of <FIG>. The exposure device <NUM> is a device that exposes the base material resist layer. The exposure device <NUM> includes a laser light source <NUM>, a first mirror <NUM>, a photodiode (PD) <NUM>, a deflecting optical system, a control mechanism <NUM>, a second mirror <NUM>, a movable optical table <NUM>, a spindle motor <NUM>, and a turntable <NUM>. In addition, the master base material <NUM> is placed on the turntable <NUM> and is capable of rotating.

The laser light source <NUM> is a light source that emits the laser light 200A, and is a device such as a solid-state laser or a semiconductor laser, for example. The wavelength of the laser light 200A emitted by the laser light source <NUM> is not particularly limited, but may be a wavelength in the blue light band from <NUM> to <NUM>, for example. In addition, it is sufficient for the spot diameter of the laser light 200A (the diameter of the spot radiated onto the resist layer) to be smaller than the diameter of the open face of a concavity of the master concave-convex structure <NUM>, such as approximately <NUM>, for example. The laser light 200A emitted from the laser light source <NUM> is controlled by the control mechanism <NUM>.

The laser light 200A emitted from the laser light source <NUM> advances directly in a collimated beam, reflects off the first mirror <NUM>, and is guided to the deflecting optical system.

The first mirror <NUM> is made up of a polarizing beam splitter, and has a function of reflecting one polarized component, and transmitting the other polarized component. The polarized component transmitted through the first mirror <NUM> is detected by the photodiode <NUM> and photoelectrically converted. In addition, a photodetection signal photoelectrically converted by the photodiode <NUM> is input into the laser light source <NUM>, and the laser light source <NUM> conducts phase modulation of the laser light 200A on the basis of the input photodetection signal.

In addition, the deflecting optical system includes a condenser lens <NUM>, an electro-optic deflector (EOD) <NUM>, and a collimator lens <NUM>.

In the deflecting optical system, the laser light 200A is condensed onto the electro-optic deflector <NUM> by the condenser lens <NUM>. The electro-optic deflector <NUM> is an element capable of controlling the radiation position of the laser light 200A. With the electro-optic deflector <NUM>, the exposure device <NUM> is also capable of changing the radiation position of the laser light 200A guided onto the movable optical table <NUM> (what is called a Wobble mechanism). After the radiation position is adjusted by the electro-optic deflector <NUM>, the laser light 200A is converted back into a collimated beam by the collimator lens <NUM>. The laser light 200A exiting the deflecting optical system is reflected by the second mirror <NUM>, and guided level with and parallel to the movable optical table <NUM>.

The movable optical table <NUM> includes a beam expander (BEX) <NUM> and an objective lens <NUM>. The laser light 200A guided to the movable optical table <NUM> is shaped into a desired beam shape by the beam expander <NUM>, and then radiated via the objective lens <NUM> onto the base material resist layer formed on the master base material <NUM>. In addition, the movable optical table <NUM> moves by one feed pitch (track pitch) in the direction of the arrow R (feed pitch direction) every time the master base material <NUM> undergoes one rotation. The master base material <NUM> is placed on the turntable <NUM>. The spindle motor <NUM> causes the turntable <NUM> to rotate, thereby causing the master base material <NUM> to rotate. Accordingly, the laser light 200A is made to scan over the base material resist layer. Herein, a latent image of the base material resist layer is formed along the scanning direction of the laser light 200A.

In addition, the control mechanism <NUM> includes a formatter <NUM> and a driver <NUM>, and controls the irradiation with the laser light 200A. The formatter <NUM> generates a modulation signal that controls the irradiation with the laser light 200A, and the driver <NUM> controls the laser light source <NUM> on the basis of the modulation signal generated by the formatter <NUM>. The irradiation of the master base material <NUM> with the laser light 200A is thereby controlled.

The formatter <NUM> generates a control signal for irradiating the base material resist layer with the laser light 200A, on the basis of an input image depicting an arbitrary pattern to be drawn on the base material resist layer. Specifically, first, the formatter <NUM> acquires an input image depicting an arbitrary draw pattern to be drawn on the base material resist layer. The input image is an image corresponding to a development view of the outer circumferential surface of the base material resist layer, in which the outer circumferential surface of the base material resist layer is cut in the axial direction and expanded in a single plane. In the development view, an image corresponding to the circumferential shape of the master <NUM> is drawn. This image illustrates the inverted structure of the inverted concave-convex structure <NUM>. Note that a transfer film to which the master concave-convex structure <NUM> of the master <NUM> has been transferred may be produced, and the inverted concave-convex structure <NUM> may be formed on the flexible base material <NUM> using this transfer film as a transfer mold. In this case, the master concave-convex structure <NUM> has the same concave-convex structure as the inverted concave-convex structure <NUM>.

Next, the formatter <NUM> partitions the input image into sub-regions of a predetermined size (for example, partitions the input image into a lattice), and determines whether or not the concavity draw pattern (in other words, a pattern corresponding to the concavities of the master <NUM>) is included in each of the sub-regions. Subsequently, the formatter <NUM> generates a control signal to perform control to irradiate with the laser light 200A each sub-region determined to include the concavity draw pattern. This control signal (that is, the exposure signal) preferably is synchronized with the rotation of the spindle motor <NUM>, but does not have to be synchronized. In addition, the control signal and the rotation of the spindle motor <NUM> may also be resynchronized every time the master base material <NUM> performs one rotation. Furthermore, the driver <NUM> controls the output of the laser light source <NUM> on the basis of the control signal generated by the formatter <NUM>. The irradiation of the base material resist layer with the laser light 200A is thereby controlled. Note that the exposure device <NUM> may also perform a known exposure control process, such as focus servo and positional correction of the irradiation spot of the laser light 200A. The focus servo may use the wavelength of the laser light 200A, or use another wavelength for reference.

In addition, the laser light 200A radiated from the laser light source <NUM> may be radiated onto the base material resist layer after being split into multiple optical systems. In this case, multiple irradiation spots are formed on the base material resist layer. In this case, when the laser light 200A emitted from one optical system reaches the latent image formed by another optical system, exposure may be ended.

Consequently, according to the present embodiment, a latent image corresponding to the draw pattern of the input image can be formed in the resist layer. Then, by developing the resist layer and using the developed resist layer as a mask to etch the master base material <NUM> and the base material resist layer, the master concave-convex structure <NUM> corresponding to the draw pattern of the input image is formed on the master base material <NUM>. In other words, an arbitrary master concave-convex structure <NUM> corresponding to a draw pattern can be formed. Consequently, if a draw pattern in which the inverted structure of the inverted concave-convex structure <NUM> is drawn is prepared as the draw pattern, the master concave-convex structure <NUM> having the inverted structure of the inverted concave-convex structure <NUM> can be formed.

Note that the exposure device usable in the present embodiment is not limited to the exposure device <NUM>, and any type of exposure device having functions similar to those of the exposure device <NUM> may be used.

Next, an example of a method for forming the inverted concave-convex structure <NUM> using the master <NUM> will be described with reference to <FIG>. The inverted concave-convex structure <NUM> can be formed on the flexible base material <NUM> by a roll-to-roll transfer device <NUM> using the master <NUM>. In the transfer device <NUM> illustrated in <FIG>, the curing resin constituting the resin layer <NUM> is what is called an ultraviolet-curing resin. The second and third master producing steps described above are performed using the transfer device <NUM>.

The transfer device <NUM> includes the master <NUM>, a base material supply roll <NUM>, a take-up roll <NUM>, guide rolls <NUM> and <NUM>, a nip roll <NUM>, a separation roll <NUM>, an applicator device <NUM>, and a light source <NUM>.

The base material supply roll <NUM> is a roll around which the long-length flexible base material <NUM> is wound in a roll, while the take-up roll <NUM> is a roll that takes up the flexible master <NUM>. In addition, the guide rolls <NUM> and <NUM> are rolls that transport the flexible base material <NUM>. The nip roll <NUM> is a roll that puts the flexible base material <NUM> on which the uncured resin layer <NUM> has been laminated, or in other words a transfer film <NUM>, in close contact with the master <NUM>. The separation roll <NUM> is a roll that separates the flexible master <NUM> from the master <NUM>.

The applicator device <NUM> includes applicator means such as a coater, and applies an uncured curing resin to the flexible base material <NUM>, and forms the uncured resin layer <NUM>. The applicator device <NUM> may be a device such as a gravure coater, a wire bar coater, or a die coater, for example. In addition, the light source <NUM> is a light source that emits light of a wavelength at which the uncured resin can be cured, and may be a device such as an ultraviolet lamp, for example.

In the transfer device <NUM>, first, the flexible base material <NUM> is delivered continuously from the base material supply roll <NUM> via the guide roll <NUM>. Note that partway through the delivery, the base material supply roll <NUM> may also be changed to a base material supply roll <NUM> of a separate lot. The uncured resin is applied by the applicator device <NUM> to the delivered flexible base material <NUM>, and the uncured resin layer <NUM> is laminated onto the flexible base material <NUM>. The transfer film <NUM> is thereby prepared. The transfer film <NUM> is put into close contact with the master <NUM> by the nip roll <NUM>. The light source <NUM> irradiates with ultraviolet rays the uncured resin layer <NUM> put in close contact with the master <NUM>, thereby curing the uncured resin layer <NUM>. Accordingly, the uncured resin layer <NUM> becomes the resin layer <NUM>, and the master concave-convex structure <NUM> is transferred to the surface of the resin layer <NUM>. In other words, the inverted structure of the master concave-convex structure <NUM>, that is, the inverted concave-convex structure <NUM>, is formed in the surface of the resin layer <NUM>. Next, the flexible base material <NUM> in which the inverted concave-convex structure <NUM> has been formed is separated from the master <NUM> by the separation roll <NUM>. Next, the flexible base material <NUM> in which the inverted concave-convex structure <NUM> has been formed is taken up by the take-up roll <NUM> via the guide roll <NUM>. Note that the master <NUM> may be oriented vertically or oriented horizontally, and a mechanism that corrects the angle and eccentricity of the master <NUM> during rotation may also be provided separately. For example, an eccentric tilt mechanism may be provided in a chucking mechanism. The transfer may also be performed by pressure transfer.

In this way, in the transfer device <NUM>, the circumferential shape of the master <NUM> is transferred to the transfer film <NUM> while transporting the transfer film <NUM> roll-to-roll. Accordingly, the inverted concave-convex structure <NUM> is formed on the flexible base material <NUM>.

Note that in the case of using a thermoplastic resin film as the flexible base material <NUM>, the applicator device <NUM> and the light source <NUM> become unnecessary. In this case, a heater device is disposed farther upstream than the master <NUM>. The flexible base material <NUM> is heated and softened by this heater device, and thereafter, the flexible base material <NUM> is pressed against the master <NUM>. Accordingly, the master concave-convex structure <NUM> formed on the circumferential surface of the master <NUM> is transferred to the flexible base material <NUM>. Note that a film including a resin other than a thermoplastic resin may be used as the flexible base material <NUM>, and the flexible base material <NUM> and a thermoplastic resin film may be laminated. In this case, the laminated film is pressed against the master <NUM> after being heated by the heater device. Consequently, the transfer device <NUM> is capable of continuously producing a transfer product in which the inverted concave-convex structure <NUM> has been formed on the flexible base material <NUM>.

In addition, a transfer film to which the master concave-convex structure <NUM> of the master <NUM> has been transferred may be produced, and the inverted concave-convex structure <NUM> may be formed on the flexible base material <NUM> using this transfer film as a transfer mold. A transfer film to which the concave-convex structure of the transfer film has been transferred further may also be used as a transfer mold. In this case, the master concave-convex structure <NUM> is formed such that the micro concave-convex structure to be formed in the resin layer <NUM> is an inverted concave-convex structure. In addition, the master <NUM> may be duplicated by electroforming, thermal transfer, or the like, and this duplicate may be used as a transfer mold. Furthermore, the shape of the master <NUM> is not necessarily limited to a roll shape, and may also be a planar master. Besides the method for irradiating resist with the laser light 200A, various processing methods can be selected, such as semiconductor exposure using a mask, electron beam lithography, machining, or anodic oxidation.

Next, an exemplary application of the resin laminated optical body <NUM> and the light source unit <NUM> will be described on the basis of <FIG>. In the example illustrated in <FIG>, the resin laminated optical body <NUM> and the light source unit <NUM> are applied to a projection image display device (that is, image projecting device) <NUM>. The image display device <NUM> has a transmissive diffusing screen structure. The image display device <NUM> includes a light irradiation device <NUM>, a liquid crystal panel <NUM>, mirrors <NUM>, <NUM>, and a display <NUM>. Light radiated from the light irradiation device <NUM> passes through the liquid crystal panel <NUM>, and is sequentially reflected off the mirrors <NUM>, <NUM>, and the display <NUM> to enter the field of view of a user (person U). That is, an image displayed on the liquid crystal panel <NUM> is displayed on the display <NUM> as a virtual image. Accordingly, the user can visually recognize an image (virtual image) displayed on the display <NUM>.

The light irradiation device <NUM> has an optical unit 1a illustrated in <FIG>. The optical unit 1a has the resin laminated optical body <NUM> and the light source unit <NUM>. In the example of <FIG>, the optical base material <NUM> is a double-concave lens, and the resin layers <NUM> are formed on both the front and rear surfaces of the optical base material <NUM>. The light sources <NUM> in the light source unit <NUM> are arranged as a matrix, and each of the light sources <NUM> emit light in a desired manner, so that a desired image can be displayed on the display <NUM>. The display <NUM> is a wind shield, combiner, or the like, for example. In a case where the image display device <NUM> is mounted on a vehicle, for example, the display <NUM> is a wind shield.

The configuration of the optical unit 1a is not limited to the example of <FIG>. For example, the resin laminated optical body <NUM> may be any of the examples indicated in <FIG>. Furthermore, either of the resin laminated optical body <NUM> and the light source unit <NUM> may be replaced by a conventional configuration. As illustrated in <FIG>, for example, the resin layer <NUM> of the light source unit <NUM> may be omitted. In addition, as illustrated in <FIG>, the resin laminated optical body <NUM> may be replaced by the optical base material <NUM> (that is, a conventional optical lens).

Furthermore, at least one of the mirrors <NUM> and <NUM> may be replaced by the resin laminated optical body <NUM>.

According to the example of <FIG>, the light irradiation device <NUM> can be reduced in size since the optical unit 1a is contained in the light irradiation device <NUM>, and eventually, the image display device <NUM> can be reduced in size. By replacing at least one of the mirrors <NUM> and <NUM> by the resin laminated optical body <NUM>, further size reduction of the image display device <NUM> can be expected. Furthermore, since interface reflection is less likely to occur between the resin layer <NUM> and the optical base material <NUM> or between the resin layer <NUM> and the optical base material <NUM>, the light emission quality, or specifically, the quality of a displayed image, can be improved (for example, luminance unevenness is reduced, or the like).

In the example of <FIG>, the resin laminated optical body <NUM> is applied to a projection image display device (that is, image projecting device) <NUM>. The image display device <NUM> has a transmissive diffusing screen structure. The image display device <NUM> includes a light irradiation device <NUM> and a display <NUM>. The light irradiation device <NUM> is a raster scanning laser irradiation device, for example, and light radiated from the light irradiation device <NUM> passes through the resin laminated optical body <NUM> to enter the display <NUM>. The light entered the display <NUM> is reflected off the display <NUM> to enter the field of view of the user. Accordingly, the user can visually recognize an image (virtual image) displayed on the display <NUM>. The display <NUM> is a combiner or the like, for example.

In this manner, in the example of <FIG>, the resin laminated optical body <NUM> is arranged on the optical path of light output from the light irradiation device <NUM>. In the example of <FIG>, the resin laminated optical body <NUM> illustrated in <FIG> is arranged, whilst any of the other resin laminated optical bodies <NUM> indicated in <FIG> may be arranged.

According to the example of <FIG>, the image display device <NUM> can be reduced in size since the resin laminated optical body <NUM> is contained in the image display device <NUM>. Furthermore, since interface reflection is less likely to occur between the resin layer <NUM> and the optical base material <NUM>, the light emission quality, or specifically, the quality of a displayed image, can be improved (for example, luminance unevenness is reduced, or the like).

In the example of <FIG>, the resin laminated optical body <NUM> is applied to a projection image display device (that is, image projecting device) <NUM>. The image display device <NUM> has a reflective diffusion screen structure. The image display device <NUM> includes a light irradiation device <NUM>, a liquid crystal panel <NUM>, a mirror <NUM>, and a display <NUM>. The light irradiation device <NUM> may be a laser light source that outputs laser light, or a LED light source, for example. Light radiated from the light irradiation device <NUM> passes through the liquid crystal panel <NUM>, and is reflected off the mirror <NUM> and the display <NUM> to enter the field of view of the user. That is, an image displayed on the liquid crystal panel <NUM> is displayed on the display <NUM> as a virtual image. Accordingly, the user can visually recognize an image (virtual image) displayed on the display <NUM>.

In the example of <FIG>, the mirror <NUM> is implemented by the resin laminated optical body <NUM>. The display <NUM> is a wind shield, combiner, or the like, for example. The configuration of the resin laminated optical body <NUM> is not limited to the example of <FIG>, but may be any of the other resin laminated optical bodies <NUM> indicated in <FIG>. In addition, the light irradiation device <NUM> may be implemented by the light irradiation device <NUM> described above.

According to the example of <FIG>, the image display device <NUM> can be reduced in size since the mirror <NUM> is implemented by the resin laminated optical body <NUM>. Furthermore, since interface reflection is less likely to occur between the resin layer <NUM> and the optical base material <NUM>, the light emission quality, or specifically, the quality of a displayed image, can be improved (for example, luminance unevenness is reduced, or the like).

In the example of <FIG>, the resin laminated optical body <NUM> is applied to a projection image display device (that is, image projecting device) <NUM>. The image display device <NUM> has a reflective diffusion screen structure. That is, the image display device <NUM> includes a light irradiation device <NUM>, a liquid crystal panel <NUM>, mirrors <NUM>, <NUM>, and a display <NUM>. The light irradiation device <NUM> may be a laser light source that outputs laser light or a LED light source, for example. Light radiated from the light irradiation device <NUM> passes through the liquid crystal panel <NUM>, and is reflected off the mirrors <NUM>, <NUM>, and the display <NUM> to enter the field of view of the user. That is, an image displayed on the liquid crystal panel <NUM> is displayed on the display <NUM> as a virtual image. Accordingly, the user can visually recognize an image (virtual image) displayed on the display <NUM>.

In the example of <FIG>, the mirrors <NUM> and <NUM> are implemented by the resin laminated optical body <NUM>. The display <NUM> is a wind shield, combiner, or the like, for example. The configuration of the resin laminated optical body <NUM> is not limited to the example of <FIG>, but may be any of the other resin laminated optical bodies <NUM> indicated in <FIG>. In addition, at least one of the mirrors <NUM> and <NUM> may be implemented by a conventional mirror.

According to the example of <FIG>, the image display device <NUM> can be reduced in size since the mirrors <NUM> and <NUM> are implemented by the resin laminated optical body <NUM>.

Next, examples of the present invention will be described. In Examples <NUM> to <NUM> and Comparative Example <NUM>, tests for evaluating properties of the light irradiation device <NUM> illustrated in <FIG> were conducted. Hereinafter, the present example will be described in detail.

The first to third master producing steps described above were performed to produce the flexible master <NUM> in which the inverted concave-convex structure <NUM> was a light diffusing structure or moth-eye structure. More specifically, a PET film having a thickness of <NUM> was prepared as the flexible base material <NUM>. Then, the resin layer <NUM> was formed on one surface of the flexible base material <NUM> using the transfer device <NUM> illustrated in <FIG>. Herein, the ultraviolet-curing acrylic resin composition "SK1120" made by Dexerials Corporation was used as the ultraviolet-curing resin. The average cycle of the inverted concave-convex structure <NUM> constituting the moth-eye structure was <NUM>, and the height difference was <NUM>. In the inverted concave-convex structure <NUM> constituting the light diffusing structure, the average interval between the micro concavities 50b and 50b and the average interval between the micro convexities 50a and 50a were <NUM>, and the height difference was <NUM>.

A plano-concave lens was prepared as the optical base material <NUM> for lens (hereinafter, also referred to as an "optical base material <NUM>-<NUM>"). Herein, the diameter (φ) of the optical base material <NUM>-<NUM> was <NUM>, the material was BK7, and the radius of curvature was <NUM>. In addition, the refractive index of the optical base material <NUM>-<NUM> was <NUM>. Herein, the radius of curvature was measured by "Three-dimensional measuring equipment UA3P" made by Panasonic Corporation, and the refractive index was measured by the Abbe refractometer made by ATAGO CO. Note that the refractive index was a refractive index corresponding to the wavelength of <NUM>.

Furthermore, as the material of the optical base material <NUM> for the light source unit <NUM>, a cycloolefin polymer ("ZEONEX 480R" made by Zeon Corporation) was prepared.

As the ultraviolet-curing resin constituting the resin layer <NUM>, an acrylic ultraviolet-curing resin having the following composition was prepared. The acrylic ultraviolet-curing resin when uncured had a viscosity (cP) of <NUM> cP and a refractive index of <NUM>. Herein, the viscosity was measured by the rotating viscometer made by Brookfield Engineering Laboratories, Inc. , and the refractive index was measured by the Abbe refractometer made by ATAGO CO. after curing. The refractive index was a refractive index corresponding to the wavelength of <NUM>.

The first to sixth steps and the separation step described above were performed to produce the light source unit <NUM>-<NUM>. Herein, the flexible master <NUM> (hereinafter, also referred to as a "flexible master <NUM>-<NUM>") in which the inverted concave-convex structure <NUM> was a moth-eye structure was used as the flexible master <NUM>. Furthermore, a white LED was used as the light source <NUM>. In addition, by directly charging a cycloolefin polymer described above onto the light source <NUM> by molding, the light source <NUM> was embedded in the optical base material <NUM>. The light source unit <NUM>-<NUM> was thereby produced. The thickness of the resin layer <NUM> was <NUM>. Note that, in all of the following examples, the thickness of the resin layer <NUM> was similar to that of Example <NUM>.

Using the flexible master <NUM> (hereinafter, also referred to as a "flexible master <NUM>-<NUM>") in which the inverted concave-convex structure <NUM> was a light diffusing structure and the ultraviolet-curing resin described above, a light diffuser panel was produced. Specifically, the ultraviolet-curing resin described above was applied onto an acrylic film to a thickness of <NUM>, and the flexible master <NUM>-<NUM> was bonded from above. By irradiating the ultraviolet-curing resin with ultraviolet rays in this state to separate the flexible master <NUM>-<NUM>, the light diffuser panel was produced.

The optical base material <NUM>-<NUM> and the light diffuser panel were arranged in this order on the light emitting surface 32a of the light source unit <NUM>-<NUM> to produce the optical unit 1a. Herein, the curved surface <NUM> of the optical base material <NUM>-<NUM> was placed to face the light diffuser panel. Hereinafter, the curved surface <NUM> shall be a "front surface" of the optical base material <NUM>-<NUM>, and the surface (the surface on the light source unit <NUM>-<NUM> side) opposite to the front surface shall be a "rear surface". Then, the light source <NUM> was caused to emit light to measure total light transmittance and diffusion angle of transmitted light having transmitted through the light diffuser panel. Herein, the total light transmittance is a ratio of an emission intensity of the transmitted light to an emission intensity of the light source <NUM>, and the diffusion angle is an angle at which, when normalizing the light intensity of each light emission angle at a light intensity of vertical transmission (<NUM>°), the light intensity becomes half. The total light transmittance was measured using "HM-<NUM>" made by MURAKAMI COLOR RESEARCH LABORATORY CO. The diffusion angle was measured using "EZ-Contrast" made by ELDIM. A white collimating light source was used as the light source. The results are collectively shown in Table <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the front surface of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A moth-eye structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>. The thickness of the resin layer <NUM> was <NUM>. Note that, in all of the following examples, the thickness of the resin layer <NUM> was similar to that of Example <NUM>.

The resin laminated optical body <NUM>-<NUM> and the light diffuser panel were arranged in this order on the light emitting surface 32a of the light source unit <NUM>-<NUM> to produce the optical unit 1a. The light diffuser panel was that used in Example <NUM>. Then, the light source <NUM> was caused to emit light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the light diffuser panel. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the rear surface of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A moth-eye structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layers <NUM> on both the front and rear surfaces of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A moth-eye structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

A light source unit <NUM>-c1 was produced in which the light source <NUM> was contained in the optical base material <NUM>. The light source unit <NUM>-c1 was obtained by omitting the resin layer <NUM> from the light source unit <NUM>-<NUM> of Example <NUM>. The optical base material <NUM>-<NUM> and the light diffuser panel were arranged in this order on the light emitting surface 32a of this light source unit <NUM>-c1 to produce an optical unit. The light diffuser panel was that used in Example <NUM>. Therefore, in the optical unit of Comparative Example <NUM>, the resin layer according to the present embodiment was not formed on either the optical base material <NUM>-<NUM> or <NUM>. Then, the light source <NUM> was caused to emit light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the light diffuser panel. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

Note that, in Table <NUM>, lenses <NUM> and <NUM> indicate the optical base materials <NUM> and <NUM>-<NUM>, respectively. For the diffuser panel, "Separately placed" indicates that the optical base material <NUM>-<NUM> and the light diffuser panel are separate from each other. The term "Not processed" indicates that no resin layer is formed. The term "Anti-reflective" indicates that a moth-eye structure is formed.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the front surface of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A light diffusing structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

The resin laminated optical body <NUM>-<NUM> was arranged on the light emitting surface 32a of the light source unit <NUM>-c1 to produce the optical unit 1a. Then, the light source <NUM> was caused to emit light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the resin laminated optical body <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

The resin laminated optical body <NUM>-<NUM> was arranged on the light emitting surface 32a of the light source unit <NUM>-<NUM> to produce the optical unit 1a. Then, the light source <NUM> was caused to emit light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the resin laminated optical body <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the rear surface of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A light diffusing structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layers <NUM> on both the front and rear surfaces of the optical base material <NUM>-<NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced. A light diffusing structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the front surface of the optical base material <NUM>-<NUM>. A light diffusing structure was formed in the surface <NUM> of this resin layer <NUM> as the micro concave-convex structure <NUM>. Furthermore, the first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the rear surface of the optical base material <NUM>-<NUM>. A moth-eye structure was formed in the surface <NUM> of this resin layer <NUM> as the micro concave-convex structure <NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the front surface of the optical base material <NUM>-<NUM>. A moth-eye structure was formed in the surface <NUM> of this resin layer <NUM> as the micro concave-convex structure <NUM>. Furthermore, the first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on the rear surface of the optical base material <NUM>-<NUM>. A light diffusing structure was formed in the surface <NUM> of this resin layer <NUM> as the micro concave-convex structure <NUM>. A resin laminated optical body <NUM>-<NUM> was thereby produced.

Note that, in Table <NUM>, the lenses <NUM> and <NUM> indicate the optical base materials <NUM> and <NUM>-<NUM>, respectively. For the diffuser panel, "Integrated with lens" indicates that a light diffusing structure is integrated with at least one of the optical base material <NUM>-<NUM> and the optical base material <NUM> (that is, a resin layer having the light diffusing structure is formed). The term "Not processed" indicates that no resin layer is formed. The term "Anti-reflective" indicates that a moth-eye structure is formed. The term "Diffusive" indicates that a light diffusing structure is formed.

The first to seventh steps and the separation step described above were performed to produce a light source unit <NUM>-<NUM>. Herein, the flexible master <NUM>-<NUM> was used as the flexible master <NUM>. The light source <NUM> similar to that of Example <NUM> was used. The light source unit <NUM>-<NUM> was thereby produced. A light diffusing structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

The optical base material <NUM>-<NUM> was arranged on the light emitting surface 32a of the light source unit <NUM>-<NUM> to produce the optical unit 1a. Then, the light source <NUM> was caused to emit light to measure the total light transmittance and diffusion angle of transmitted light transmitted through the optical base material <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

In Examples <NUM> to <NUM> and Comparative Example <NUM>, tests for evaluating optical properties of the image display device <NUM> illustrated in <FIG> (in particular, around the light irradiation device <NUM>) were conducted. Hereinafter, detailed description will be provided.

A raster scanning laser irradiation device was prepared as the light irradiation device <NUM>. A resin laminated optical body <NUM>-<NUM> was arranged on the optical path of this light irradiation device <NUM>. Herein, the front surface of the resin laminated optical body <NUM>-<NUM> (the front surface of the optical base material <NUM>-<NUM>) was directed to the display <NUM> side. Then, the light irradiation device <NUM> was caused to output light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the resin laminated optical body <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

The resin laminated optical body <NUM>-<NUM> was arranged on the optical path of the light irradiation device <NUM>. Herein, the front surface of the resin laminated optical body <NUM>-<NUM> (the front surface of the optical base material <NUM>-<NUM>) was directed to the display <NUM> side. Then, the light irradiation device <NUM> was caused to output light to measure the total light transmittance and diffusion angle of transmitted light having transmitted through the resin laminated optical body <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

A light diffuser panel and the optical base material <NUM>-<NUM> were arranged in this order on the optical path of the light irradiation device <NUM>. The light diffuser panel was that used in Example <NUM>. Herein, the front surface of the optical base material <NUM>-<NUM> was directed to the display <NUM> side. Then, the light irradiation device <NUM> was caused to output light to measure the total light transmittance and diffusion angle of transmitted light transmitted through the optical base material <NUM>-<NUM>. Measuring conditions were similar to those of Example <NUM>. The results are collectively shown in Table <NUM>.

Note that, in Table <NUM>, the lens indicates the optical base material <NUM>-<NUM>. For the diffuser panel, "Integrated with lens" indicates that a light diffusing structure is integrated with the optical base material <NUM>-<NUM> (that is, a resin layer having the light diffusing structure is formed). The term "Separately placed" indicates that the light diffuser panel and the optical base material <NUM>-<NUM> are separate from each other. The term "Not processed" indicates that no resin layer is formed. The term "Anti-reflective" indicates that a moth-eye structure is formed. The term "Diffusive" indicates that a light diffusing structure is formed.

In Example <NUM> and Comparative Example <NUM>, tests for evaluating optical properties of the image display device <NUM> illustrated in <FIG> were conducted. Hereinafter, detailed description will be provided.

As the optical base material <NUM> for mirror (hereinafter, also referred to as an "optical base material <NUM>-<NUM>"), an object obtained by depositing an aluminum metal film on a cycloolefin polymer ("ZEONEX 480R" made by Zeon Corporation) base material through vacuum deposition was prepared.

The first to sixth steps and the separation step described above were performed using the flexible master <NUM>-<NUM> to form the resin layer <NUM> on a reflective surface of the optical base material <NUM>-<NUM> (the surface on which the curved surface <NUM> is formed). A resin laminated optical body <NUM>-<NUM> was thereby produced. A light diffusing structure was formed in the surface <NUM> of the resin layer <NUM> as the micro concave-convex structure <NUM>.

A white LED was prepared as the light irradiation device <NUM>. Then, the light irradiation device <NUM>, the liquid crystal panel <NUM>, the mirror <NUM>, and the display <NUM> were arranged in the image display device <NUM>. Herein, the resin laminated optical body <NUM>-<NUM> was used as the mirror <NUM>. Then, the light irradiation device <NUM> was caused to output light, and reflected light having been reflected off the resin laminated optical body <NUM>-<NUM> was caused to enter the display <NUM>. A virtual image was thereby displayed on the display <NUM>. A luminance difference between central luminance of this virtual image and luminance at the outer edge was measured. The luminance was measured using "CS-<NUM>" made by KONICA MINOLTA Inc. The luminance at the outer edge was an arithmetic mean value of values measured at a plurality of measurement points. Then, in a case where the luminance difference was less than or equal to <NUM>% of the central luminance, luminance unevenness was determined as pass (the luminance is less uneven), and in a case where the luminance difference exceeded <NUM>% of the central luminance, luminance unevenness was determined as fail (the luminance is much uneven). In Example <NUM>, the luminance unevenness was at a pass level. The results are collectively shown in Table <NUM>.

Tests similar to those of Example <NUM> were conducted except that the resin laminated optical body <NUM>-<NUM> was changed to the optical base material <NUM>-<NUM>. In Comparative Example <NUM>, the luminance unevenness was at a fail level. The results are collectively shown in Table <NUM>.

Note that, in Table <NUM>, the mirror indicates the mirror <NUM>. The term "Non-diffusive" indicates that no light diffusing structure is formed in the optical base material <NUM>-<NUM>. The term "Diffusive" indicates that a light diffusing structure is formed in the optical base material <NUM>-<NUM>. For the luminance unevenness, the mark "o" indicates "pass", and the mark "×" indicates "fail".

In Examples <NUM> to <NUM> and Comparative Example <NUM>, tests for evaluating optical properties of the image display device <NUM> illustrated in <FIG> were conducted. Hereinafter, detailed description will be provided.

A white LED was prepared as the light irradiation device <NUM>. Then, the light irradiation device <NUM>, the liquid crystal panel <NUM>, the mirrors <NUM>, <NUM>, and the display <NUM> were arranged in the image display device <NUM>. Herein, the resin laminated optical body <NUM>-<NUM> was used as the mirror <NUM>, and the optical base material <NUM>-<NUM> was used as the mirror <NUM>. Then, the light irradiation device <NUM> was caused to output light, and reflected light having been reflected off the resin laminated optical body <NUM>-<NUM> was caused to enter the display <NUM>. A virtual image was thereby displayed on the display <NUM>. A luminance difference between central luminance of this virtual image and luminance at the outer edge was measured. The luminance was measured similarly to Example <NUM>. Then, in a case where the luminance difference was less than or equal to <NUM>% of the central luminance, luminance unevenness was determined as pass (the luminance is less uneven), and in a case where the luminance difference exceeded <NUM>% of the central luminance, luminance unevenness was determined as fail (the luminance is much uneven). In Example <NUM>, the luminance unevenness was at a pass level. The results are collectively shown in Table <NUM>.

Tests similar to those of Example <NUM> were conducted except that the optical base material <NUM>-<NUM> was used as the mirror <NUM>, and the resin laminated optical body <NUM>-<NUM> was used as the mirror <NUM>. The luminance unevenness was at a pass level. The results are collectively shown in Table <NUM>.

Tests similar to those of Example <NUM> were conducted except that the resin laminated optical body <NUM>-<NUM> was used as the mirrors <NUM> and <NUM>. The luminance unevenness was at a pass level. The results are collectively shown in Table <NUM>.

Tests similar to those of Example <NUM> were conducted except that the optical base material <NUM>-<NUM> was used as the mirrors <NUM> and <NUM>. The luminance unevenness was at a fail level. The results are collectively shown in Table <NUM>.

Note that, in Table <NUM>, mirrors <NUM> and <NUM> indicate the mirrors <NUM> and <NUM>, respectively. The remaining terms are similar to those of Table <NUM>.

As is clear from Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM>, the light emission quality concerning total light transmittance, luminance unevenness, or the like was improved in Examples <NUM> to <NUM> that satisfy requirements of the present embodiment as compared with Comparative Examples <NUM> to <NUM>.

Claim 1:
A light source unit (<NUM>) comprising:
an optical base material (<NUM>),
a light source (<NUM>) integrated with the optical base material (<NUM>); and
a resin layer (<NUM>) provided on a light emitting surface of the optical base material (<NUM>), wherein
a curved surface (<NUM>) is formed on an interface (32a) of the optical base material (<NUM>) with the resin layer (<NUM>), and the resin layer (<NUM>) is laminated along the curved surface (<NUM>), and the curved surface (<NUM>) of the optical base material (<NUM>) allows the optical base material (<NUM>) to function as a lens for the light source (<NUM>), and
a micro concave-convex structure (<NUM>) is formed in a surface (<NUM>) of the resin layer (<NUM>).