Aerial image forming device and laminate

Abstract

The present invention provides an aerial image forming device 10a, 10b comprising: a display unit 1 which has a display surface and which emits light from the display surface; a light-transmissive image forming unit 2 which is disposed on the display-surface side of the display unit 1, transmits the light, and causes an image to be formed at a position on the opposite side of the display unit 1; and an antistatic layer 3 containing an antistatic agent and laminated on the surface of the light-transmissive image forming unit 2 that is on the display unit 1 side or on the surface of the light-transmissive image forming unit 2 that is on the side opposite from the display unit 1. The aerial image forming device 10a, 10b has excellent antistatic properties and excellent visibility.

Description

Aerial image forming device and laminate

[0001] The present invention relates to an aerial image forming device and a laminate for forming the aerial image forming device.

[0002] Aerial images are images formed at any position in space by reflecting and refracting light emitted from a light source using optical elements. There is no screen or display at the position where the aerial image is displayed, so viewers who view the aerial image experience a mysterious sensation. For this reason, aerial images have been used in various applications in recent years, including virtual reality.

[0003] For example, Patent Document 1 discloses an aerial image forming device that includes at least a display unit and a light-transmitting imaging unit, in which an image (real image) displayed on the display unit is displayed as an aerial image primarily through the action of the light-transmitting imaging unit.

[0004] Japanese Patent Application Laid-Open No. 2020-060752

[0005] Generally, aerial image forming devices can become charged with static electricity due to the surrounding environment or contact with the user. When an aerial image forming device becomes charged, it can cause discomfort to the user and lead to malfunctions or breakdowns of the device. Furthermore, dust and other particles can adhere to the exposed surface of the aerial image forming device (especially the surface opposite the display unit in the translucent imaging unit), potentially reducing the visibility of the aerial image.

[0006] The present invention has been made in consideration of the above-described circumstances, and its primary object is to provide an aerial image forming device that has excellent antistatic properties and excellent visibility, and a laminate for forming the aerial image forming device.

[0007] In general, in an aerial image forming device, the display unit and the optically transparent imaging unit are housed in a housing. In this case, one side of the optically transparent imaging unit is exposed to the outside of the aerial image forming device, and the user can see the exposed side of the optically transparent imaging unit. Therefore, if the appearances of the housing and the optically transparent imaging unit differ, the user may feel that the appearances are mismatched.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and a second object of the present invention is to provide an aerial image forming device that has an excellent harmonious appearance, and a laminate for forming the aerial image forming device.

[0009] Furthermore, when an aerial image forming device is operated, an unintended image called a ghost image may be displayed simultaneously with the aerial image. The occurrence of a ghost image is unintended and cannot be said to accurately reflect the real image. In addition, the ghost image may overlap with the aerial image, making it difficult to clearly view the aerial image.

[0010] From the viewpoint of suppressing the occurrence of such ghost images, the inventors have found that the occurrence of ghost images can be effectively suppressed by providing a light diffusion control unit in the aerial image forming device that diffuses or transmits light depending on the angle of incidence. Specifically, the inventors have found that the occurrence of ghost images can be effectively suppressed by providing the light diffusion control unit on the display unit side of the light-transmitting image forming unit.

[0011] Furthermore, in an aerial image forming device, disturbance light caused by an external light source may be perceived along with the aerial image. For example, if the aerial image forming device is installed under a fluorescent lamp, the viewer may see disturbance light corresponding to the fluorescent lamp, which may interfere with the viewing of the aerial image.

[0012] Here, disturbance light is not simply light reflected from the surface of the translucent imaging unit, but light that penetrates the translucent imaging unit and returns to the observer. Because it causes color breakup due to diffraction, it significantly reduces visibility compared to the reflection of a general external light source.

[0013] Since aerial image forming devices are also expected to be used in places where there are many external light sources, such as convenience stores, supermarkets, and inside mobile vehicles such as automobiles, it is necessary to suppress the effects of external light such as those described above.

[0014] The inventors have found that the above-described light diffusion control unit is also effective in suppressing the generation of ambient light. That is, the inventors have found that by providing the light diffusion control unit on the surface of the light-transmitting imaging unit opposite to the display unit, the generation of ambient light can be effectively suppressed.

[0015] Generally, in an aerial image forming device, the display unit, the light-transmitting imaging unit, etc. are housed in a housing. In this case, a part of the light-transmitting imaging unit and the laminated body made up of the light-transmitting imaging unit, etc. are exposed to the outside of the aerial image forming device, making it susceptible to external influences. In particular, when the aerial image forming device is placed outdoors, the laminated body is exposed to sunlight.

[0016] The inventors discovered that the light diffusion control section is prone to deterioration such as yellowing when exposed to light such as sunlight for a long period of time. Such light deterioration is a major cause of impairing the visibility of the aerial image.

[0017] The present invention has been made in consideration of the above-described situation, and a third object of the present invention is to provide an aerial image forming device that has excellent weather resistance and allows aerial images to be clearly viewed, and a laminate for forming the aerial image forming device.

[0018] In order to achieve the above object, first, the present invention provides an aerial image forming device comprising: a display unit having a display surface and emitting light from the display surface; a light-transmitting image forming unit disposed on the display surface side of the display unit, transmitting the light and forming an image at a position on the side opposite the display unit; and a functional layer laminated on the display unit side of the light-transmitting image forming unit or on the side opposite the display unit of the light-transmitting image forming unit, wherein the functional layer is any one of an antistatic layer containing an antistatic agent, a colored layer containing a coloring component, and a light diffusion control unit, and when the functional layer is the colored layer, a laminate of the light-transmitting image forming unit and the colored layer is measured by a CIE 1976L standard against a black plate. ＊ a ＊ b ＊ Color difference ΔE defined by the color system ＊is 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less, and when the functional layer is the light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure including a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index, and the aerial image forming device further includes a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control section contains an ultraviolet absorber (Invention 1).

[0019] In the above invention (Invention 1), it is preferable that the functional layer is the antistatic layer, and the antistatic layer is at least one of a coating layer containing the antistatic agent, a pressure-sensitive adhesive layer containing the antistatic agent, a substrate containing the antistatic agent, and a light diffusion control section containing the antistatic agent, and that the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index (Invention 2).

[0020] In the above inventions (Inventions 1 and 2), it is preferable that the functional layer is the antistatic layer, and that the display unit is arranged with respect to the translucent imaging unit and the antistatic layer so that the display surface and one side of the translucent imaging unit are non-parallel (Invention 3).

[0021] In the above invention (Invention 2), when the functional layer is the antistatic layer, the antistatic layer is the light diffusion control unit, and the direction perpendicular to the longitudinal direction of the plate-shaped region and existing in the plane opposite the translucent imaging unit in the light diffusion control unit is defined as a first direction, it is preferable that each of the plate-shaped regions is inclined toward the first direction within the light diffusion control unit (Invention 4).

[0022] In the above invention (Invention 1), it is preferable that the functional layer is the colored layer, and the colored layer is a pressure-sensitive adhesive layer containing the coloring component (Invention 5).

[0023] In the above invention (Invention 1), it is preferable that the functional layer is the colored layer, the aerial image forming device has a light diffusion control section laminated on the side of the translucent imaging section opposite the display section or on the side of the translucent imaging section on which the display section is formed, and the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with multiple plate-shaped regions with a relatively high refractive index within a region with a relatively low refractive index (Invention 6).

[0024] In the above invention (Invention 6), it is preferable that the light diffusion control section contains a coloring component, and the aerial image forming device includes the light diffusion control section as the colored layer (Invention 7).

[0025] In the above invention (Invention 1), it is preferable that the functional layer is the colored layer, and the display unit is arranged relative to the light-transmitting image forming unit so that the display surface and one side of the light-transmitting image forming unit are non-parallel (Invention 8).

[0026] In the above invention (Invention 6), if the direction perpendicular to the longitudinal direction of the plate-shaped region and existing in the plane opposite the light-transmitting imaging section in the light diffusion control section is defined as the first direction, it is preferable that each of the plate-shaped regions is inclined toward the first direction within the light diffusion control section (Invention 9).

[0027] In the above invention (Invention 1), it is preferable that the functional layer is the light diffusion control unit, and the weather-resistant layer is provided on the side of the translucent imaging unit opposite the light diffusion control unit, the side of the light diffusion control unit opposite the translucent imaging unit, and at least one position between the translucent imaging unit and the light diffusion control unit (Invention 10).

[0028] In the above invention (Invention 1), it is preferable that the functional layer is the light diffusion control part, and the weather-resistant layer is at least one of a coating layer containing the ultraviolet absorber, a pressure-sensitive adhesive layer containing the ultraviolet absorber, an adhesive layer containing the ultraviolet absorber, and a substrate containing the ultraviolet absorber (Invention 11).

[0029] In the above invention (Invention 1), it is preferable that the functional layer is the light diffusion control unit, and that the display unit is arranged relative to the light diffusion control unit and the light-transmitting image forming unit so that the display surface and the surface of the light diffusion control unit opposite the light-transmitting image forming unit are non-parallel (Invention 12).

[0030] In the above invention (Invention 1), when the functional layer is the light diffusion control unit, and the direction perpendicular to the longitudinal direction of the plate-shaped region and existing in the plane opposite the light-transmitting imaging unit in the light diffusion control unit is defined as a first direction, it is preferable that each of the plate-shaped regions is inclined toward the first direction within the light diffusion control unit (Invention 13).

[0031] In the above inventions (Inventions 1 to 13), it is preferable that the light-transmitting imaging unit includes a retrotransmitting optical element that retrotransmits incident light (Invention 14).

[0032] In the above invention (Invention 14), the retrotransmitting optical element is preferably formed by stacking two layers each having a plurality of reflective surfaces, and in each of the two layers, the plurality of reflective surfaces are arranged perpendicular to one side of the retrotransmitting optical element and at a predetermined distance from each other, and the two layers are preferably stacked so that the reflective surface in one layer is perpendicular to the reflective surface in the other layer (Invention 15).

[0033] Secondly, the present invention provides a laminate comprising a light-transmitting imaging section that forms an image of light incident from one surface at a position on the other surface side, and a functional layer laminated on one surface side of the light-transmitting imaging section, wherein the functional layer is any one of an antistatic layer containing an antistatic agent, a colored layer containing a coloring component, and a light diffusion control section, and when the functional layer is the colored layer, the laminate of the light-transmitting imaging section and the colored layer is measured by a CIE 1976L standard against a black plate. ＊ a ＊ b ＊ Color difference ΔE defined by the color system ＊is 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less, and when the functional layer is the light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index, and the laminate further comprises a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control section contains an ultraviolet absorber (Invention 16).

[0034] In the above invention (Invention 16), it is preferable that the functional layer is the antistatic layer, and the antistatic layer is at least one of a coating layer containing the antistatic agent, a pressure-sensitive adhesive layer containing the antistatic agent, a substrate containing the antistatic agent, and a light diffusion control portion containing the antistatic agent, and that the light diffusion control portion diffuses or transmits light incident into the light diffusion control portion depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index (Invention 17).

[0035] In the above invention (Invention 16), it is preferable that the functional layer is the colored layer, and the colored layer is a pressure-sensitive adhesive layer containing the coloring component (Invention 18).

[0036] In the above invention (Invention 16), it is preferable that the functional layer is the colored layer, the laminate has a light diffusion control section laminated on either side of the light-transmitting imaging section, and the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with multiple plate-like regions with a relatively high refractive index within a region with a relatively low refractive index (Invention 19).

[0037] In the above invention (Invention 19), it is preferable that the functional layer is the colored layer, the light diffusion control part contains a colored component, and the laminate has the light diffusion control part as the colored layer (Invention 20).

[0038] First, the aerial image forming device according to the present invention has excellent antistatic properties and excellent visibility. Furthermore, the laminate according to the present invention makes it possible to form the above-mentioned aerial image forming device.

[0039] Second, the aerial image forming device according to the present invention has an excellent harmonious appearance. Furthermore, the laminate according to the present invention makes it possible to form the above-mentioned aerial image forming device.

[0040] Third, the aerial image forming device according to the present invention has excellent weather resistance and allows the aerial image to be clearly visible. Furthermore, the laminate according to the present invention makes it possible to form the above-mentioned aerial image forming device.

[0041] FIG. 1 is a cross-sectional view schematically showing an example of an aerial image forming device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing another example of an aerial image forming device according to the first embodiment of the present invention. FIG. 3 is a perspective view schematically showing the internal structure of a light diffusion control unit according to the first embodiment. FIG. 4 is a cross-sectional view schematically showing an example of an aerial image forming device according to a second embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing another example of an aerial image forming device according to the second embodiment of the present invention. FIG. 6 is a perspective view schematically showing the internal structure of a light diffusion control unit according to the second embodiment. FIG. 7 is a cross-sectional view schematically showing an example of an aerial image forming device according to a third embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing another example of an aerial image forming device according to the third embodiment of the present invention. FIG. 9 is a cross-sectional view schematically showing yet another example of an aerial image forming device according to the third embodiment of the present invention. FIG. 10 is a perspective view schematically showing the internal structure of a light diffusion control unit according to the third embodiment. FIG. 11 is a diagram illustrating the relationship between the optical characteristics of a light diffusion control unit according to the third embodiment and light that forms an aerial image and a ghost image. FIG. 12 is a diagram illustrating the layer structure of a laminate produced in an example according to the third embodiment.

[0042] An aerial image forming device according to this embodiment includes a display unit having a display surface and emitting light from the display surface, a light-transmitting imaging unit disposed on the display surface side of the display unit, transmitting the light and forming an image at a position on the surface side opposite the display unit, and a functional layer laminated on the display surface side of the light-transmitting imaging unit or on the surface side of the light-transmitting imaging unit opposite the display unit.

[0043] The functional layer is any one of an antistatic layer containing an antistatic agent, a colored layer containing a coloring component, and a light diffusion control portion.

[0044] Furthermore, when the functional layer is the colored layer, a laminate of the light-transmitting image forming unit and the colored layer is measured by CIE1976L against a black plate. ＊ a ＊ b ＊ Color difference ΔE defined by the color system ＊ is 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less.

[0045] Furthermore, when the functional layer is the light diffusion control unit, the light diffusion control unit diffuses or transmits light incident into the light diffusion control unit depending on the angle of incidence, and has a louvered regular internal structure with multiple plate-shaped regions with a relatively high refractive index within a region with a relatively low refractive index, and the aerial image forming device further has a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control unit contains an ultraviolet absorber.

[0046] The laminate according to this embodiment is the aerial image forming device from which the display unit is omitted.

[0047] In this specification, the aerial image forming device and laminate according to this embodiment will be described below in the following manner: a first embodiment in which the functional layer is an antistatic layer, a second embodiment in which the functional layer is a colored layer, and a third embodiment in which the functional layer is a light diffusion control unit.

[0048] 1 and 2 are cross-sectional views each showing a schematic example of an aerial image forming device according to a first embodiment. As shown in Fig. 1 and Fig. 2, the aerial image forming devices 10a and 10b according to the first embodiment include a display unit 1 having a display surface and emitting light from the display surface, a light-transmitting image forming unit 2 disposed on the display surface side of the display unit 1 and transmitting the light to form an image at a position on the side opposite the display unit 1, and an antistatic layer 3 containing an antistatic agent.

[0049] In particular, in the aerial image forming device 10a shown in Fig. 1, the antistatic layer 3 is laminated on the surface of the translucent imaging unit 2 opposite the display unit 1. In addition, in the aerial image forming device 10b shown in Fig. 2, the antistatic layer 3 is laminated on the surface of the translucent imaging unit 2 facing the display unit 1.

[0050] As described above, the aerial image forming devices 10a, 10b according to the first embodiment are provided with an antistatic layer 3 containing an antistatic agent, thereby exhibiting excellent antistatic properties. As a result, the aerial image forming devices 10a, 10b are less likely to become charged, which reduces discomfort to users and reduces the risk of malfunctions and breakdowns due to charging. Furthermore, dust and other particles are less likely to adhere to the aerial image forming devices 10a, 10b (particularly the side of the translucent imaging unit opposite the display unit), ensuring a clear optical path for light from the display surface. As a result, aerial images can be displayed satisfactorily.

[0051] 1. Display Unit The display unit 1 constituting the aerial image forming devices 10a, 10b according to the first embodiment is not particularly limited as long as it has a display surface and is capable of displaying an image on the display surface and emitting light toward the light-transmitting imaging unit 2 and the antistatic layer 3. For example, the display unit 1 may be a liquid crystal display (LCD) display, a light-emitting diode (LED) display, an organic electroluminescence (organic EL) display, or the like.

[0052] The positional relationship between the display unit 1 and the light-transmitting image forming unit 2 and the antistatic layer 3 is not particularly limited. As shown in Figures 1 and 2, it is preferable that the display unit 1 and the light-transmitting image forming unit 2 are sufficiently separated, with a space being present between them. It is also preferable that the display unit 1 is disposed relative to the light-transmitting image forming unit 2 so that the display surface of the display unit 1 and one surface of the light-transmitting image forming unit 2 are non-parallel. This positional relationship allows for better display of the aerial image.

[0053] 2. Transilluminating Imaging Unit The transilluminating imaging unit 2 constituting the aerial image forming device 10a, 10b according to the first embodiment is not particularly limited as long as it can transmit light originating from the display unit 1 and form an aerial image on a predetermined aerial image observation plane. An example of such a transilluminating imaging unit 2 is a retrotransmissive optical element that retrotransmits incident light. Note that the "aerial image observation plane" refers to the surface indicated by the symbol "4" in Figures 1-2, 4-5, and 7-9. Furthermore, the point indicated by the symbol "5" in Figures 1-2, 4-5, and 7-9 is referred to as the "observation point."

[0054] Although conventionally known retrotransmitting optical elements can be used, from the viewpoint of facilitating good aerial image formation, a retrotransmitting optical element having a two-sided orthogonal reflector array structure or a retrotransmitting optical element having a two-sided corner reflector array structure is preferred, and a retrotransmitting optical element having a two-sided orthogonal reflector array structure is more preferred. Examples of retrotransmitting optical elements having a two-sided orthogonal reflector array structure include those described in Japanese Patent No. 5,085,631. That is, as a retrotransmitting optical element having a two-sided orthogonal reflector array structure, it is preferable to use a retrotransmitting optical element formed by stacking two layers each having a plurality of reflective surfaces. In particular, in the retrotransmitting optical element, it is preferable that in each of the two layers, a plurality of reflective surfaces are arranged perpendicular to one surface of the retrotransmitting optical element and at a predetermined interval from each other, and that the two layers are stacked so that the reflective surface in one layer is perpendicular to the reflective surface in the other layer. Specifically, a retrotransmitting optical element having a surface corner reflector array structure may have the structure described in International Publication WO2007 / 116639.

[0055] The thickness of the light-transmitting imaging unit 2 is preferably 0.1 to 20 mm, more preferably 0.5 to 15 mm, particularly preferably 1 to 12 mm, even more preferably 2 to 10 mm, and most preferably 4 to 8 mm. When the thickness of the light-transmitting imaging unit 2 is within the above range, the aerial image forming devices 10a and 10b according to the first embodiment can more easily display brighter aerial images.

[0056] 3. Antistatic Layer The material and configuration of the antistatic layer 3 in the first embodiment are not limited as long as it contains an antistatic agent. For example, the antistatic layer 3 is preferably at least one of a coating layer containing an antistatic agent, a pressure-sensitive adhesive layer containing an antistatic agent, a substrate containing an antistatic agent, and a light diffusion control portion containing an antistatic agent. From the perspective of the SDGs, the material constituting the antistatic layer 3 may be a material with a high biomass content, a recyclable or reusable material, or a recycled or reused material.

[0057] (1) Antistatic Agent Examples of the antistatic agent include conductive polymers, conductive fillers, anionic or cationic compounds, and compounds having a quaternary ammonium base in the main chain or side chain of the molecule.

[0058] Examples of conductive polymers include polythiophene-, polyaniline-, and polypyrrole-based conductive polymers. Examples of polythiophene-based conductive polymers include polythiophene, poly(3-alkylthiophene), poly(3-thiophene-β-ethanesulfonic acid), and mixtures of polyalkylenedioxythiophene and polystyrene sulfonate. Examples of polyalkylenedioxythiophenes include polyethylene dioxythiophene, polypropylene dioxythiophene, and poly(ethylene / propylene) dioxythiophene. Examples of polyaniline-based conductive polymers include polyaniline, polymethylaniline, and polymethoxyaniline. Examples of polypyrrole-based conductive polymers include polypyrrole, poly(3-methylpyrrole), and poly(3-octylpyrrole). These conductive polymer compounds may be used alone or in combination of two or more. These conductive polymers are preferably dispersed in water and used in the form of an aqueous solution.

[0059] Examples of the conductive filler include particles of gold, silver, copper, nickel, aluminum, stainless steel, carbon, conductive ceramics, tin oxide, antimony-doped tin oxide (ATO), indium oxide-tin oxide (ITO), zinc oxide, antimony pentoxide, etc. These may be used alone or in combination of two or more.

[0060] From the viewpoint of facilitating the formation of a desired antistatic layer, the average particle size of the conductive filler is preferably 1 to 1,000 nm, more preferably 10 to 500 nm, particularly preferably 20 to 200 nm, and particularly preferably 30 to 100 nm.

[0061] Examples of anionic and cationic compounds include ionic liquids, ionic solids, anionic surfactants, alkali metal salts, cationic surfactants, and nonionic surfactants. Examples of ionic liquids and ionic solids include nitrogen-containing onium salts, sulfur-containing onium salts, and phosphorus-containing onium salts. Examples of alkali metal salts include lithium salts and potassium salts. These may be used alone or in combination of two or more.

[0062] Specific examples of compounds having a quaternary ammonium base include pyrrolidium rings, quaternized alkylamines, copolymers thereof with acrylic acid or methacrylic acid, quaternized N-alkylaminoacrylamides, vinylbenzyltrimethylammonium salts, 2-hydroxy-3-methacryloxypropyltrimethylammonium salts, etc. These may be used alone or in combination of two or more.

[0063] The compound having a quaternary ammonium salt group is preferably a polymer compound. The number average molecular weight of the compound having a quaternary ammonium salt group is preferably 1,000 or more, particularly preferably 2,000 or more, and even more preferably 5,000 or more. Furthermore, the upper limit of the number average molecular weight is preferably 500,000 or less, from the viewpoint of preventing the viscosity of the coating liquid containing the conductive material from becoming too high. Note that the number average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0064] (2) Coating Layer When the antistatic layer 3 is a coating layer, the coating layer is preferably laminated on the side of the light-transmitting image forming unit 2 opposite the display unit 1, as shown in Fig. 1, and serves to protect the surface of the light-transmitting image forming unit 2. The coating layer may be formed on a substrate, and in this case, a coating film including the coating layer and the substrate may be laminated on the light-transmitting image forming unit 2. The coating layer serving as the antistatic layer 3 may have a configuration in which multiple layers are laminated.

[0065] The coating layer is preferably formed by curing a coating composition containing an active energy ray-curable component, an antistatic agent, and other additives.

[0066] (2-1) Active Energy Ray-Curable Component Preferred examples of the active energy ray-curable component include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, and active energy ray-curable polymers. Among these, polyfunctional (meth)acrylate monomers or (meth)acrylate prepolymers are more preferred. The polyfunctional (meth)acrylate monomers and (meth)acrylate prepolymers may be used alone or in combination. In this specification, (meth)acrylate refers to both acrylate and methacrylate. In addition, in this specification, (meth)acrylic acid ester refers to both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms. Furthermore, the term "polymer" also includes the concept of "copolymer." The same applies to other similar terms.

[0067] Examples of polyfunctional (meth)acrylate monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, and trimethylolpropane tri(meth)acrylate. Examples of the polyfunctional (meth)acrylate include polyfunctional (meth)acrylates such as acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These may be used alone or in combination of two or more.

[0068] Examples of the (meth)acrylate prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate prepolymers.

[0069] The polyester acrylate prepolymer can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, which is obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid, with (meth)acrylic acid.

[0070] The epoxy acrylate prepolymer can be obtained, for example, by reacting the oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin with (meth)acrylic acid to esterify it.

[0071] The urethane acrylate prepolymer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate with (meth)acrylic acid.

[0072] The polyol acrylate prepolymer can be obtained, for example, by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0073] It is also preferable to use an organic-inorganic hybrid resin as the active energy ray-curable component. A preferred example of the organic-inorganic hybrid resin is a substance obtained by bonding an organic compound having a polymerizable unsaturated group to inorganic fine particles such as silica via a silane coupling agent or the like. This organic-inorganic hybrid resin is also preferably in the form of an organosol (colloid) (e.g., silica sol), and is also preferably used by mixing with an active energy ray-curable component such as the above-mentioned polyfunctional (meth)acrylate monomer. The inorganic fine particles contained in the organic-inorganic hybrid resin do not correspond to the filler described below, but function as a binder, and can improve the hardness of the coating layer formed.

[0074] (2-2) Antistatic Agent When the antistatic layer 3 is a coating layer, the antistatic agent can be appropriately selected from those described above. The content of the antistatic agent in the coating composition is preferably 1 to 1,000 parts by mass, more preferably 10 to 800 parts by mass, particularly preferably 15 to 600 parts by mass, and even more preferably 20 to 400 parts by mass, per 100 parts by mass of the active energy ray-curable component. This makes it easier to achieve better antistatic properties.

[0075] (2-3) Other Additives The coating composition of the first embodiment may contain various additives in addition to the above components. Examples of the various additives include photopolymerization initiators, fillers, hollow silica fine particles, dispersants, surface conditioners, leveling agents, ultraviolet absorbers, antioxidants, light stabilizers, silane coupling agents, antiaging agents, thermal polymerization inhibitors, colorants, infrared absorbers, surfactants, storage stabilizers, plasticizers, lubricants, antifoaming agents, organic fillers, wettability improvers, coating surface improvers, and dispersants.

[0076] In particular, from the viewpoint of efficiently promoting the crosslinking reaction of the active energy ray-curable component, the coating composition preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyphenyl)-2-propan-1- ... Examples of the hydroxybenzoates include (hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, and p-dimethylaminobenzoic acid esters. These may be used alone or in combination of two or more.

[0077] The content of the photopolymerization initiator in the coating composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 15 parts by mass, particularly preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the active energy ray-curable component. This allows a coating layer having the desired hardness to be obtained.

[0078] (2-4) Physical Properties of Coating Layer When the antistatic layer 3 is a coating layer, the surface resistance of the antistatic layer 3 on the side opposite to the light-transmitting image forming section 2 is 1.00×10 １３ Ω・□ －１ Preferably, it is 1.00 x 10 or less. １２ Ω・□ －１ More preferably, it is equal to or less than 1.00×10 １１ Ω・□ －１ It is preferable that the value is 6.00 × 10 or less, and more preferably 6.00 × 10 １０ Ω・□ －１ It is preferable that the value is equal to or less than 3.00×10 １０ Ω・□ －１ It is preferable that the surface resistivity is not more than 1.0×10. This makes it easier to achieve better antistatic properties. The lower limit of the surface resistivity is not particularly limited, and may be, for example, 1.0×10 ３ Ω・□ －１ or more, particularly 1.0 × 10 ４ Ω・□ －１ or more, and even 1.0 × 10 ５ Ω・□ －１ The details of the method for measuring the surface resistance are as described in the test examples below.

[0079] When the antistatic layer 3 is a coating layer, the thickness of the coating layer is preferably 0.001 to 100 μm, more preferably 0.01 to 75 μm, particularly preferably 0.1 to 50 μm, even more preferably 1 to 20 μm, and most preferably 2 to 10 μm. This makes it easier to achieve better antistatic properties. Note that when the coating layer is composed of multiple layers as described above, the thickness referred to here refers to the total thickness of the multiple layers.

[0080] (3) Adhesive Layer When the antistatic layer 3 is an adhesive layer, the adhesive layer is preferably used to bond the components constituting the aerial image forming devices 10 a, 10 b together. For example, when the aerial image forming devices 10 a, 10 b include a light diffusion control unit, the adhesive layer as the antistatic layer 3 is preferably laminated between the light diffusion control unit and the light-transmitting imaging unit 2 to bond them together.

[0081] The adhesive constituting the adhesive layer is not particularly limited. From the viewpoint of facilitating good visibility of the aerial image, it is preferable that the adhesive has transparency. Specific examples of the adhesive include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, and urethane adhesives, but from the viewpoint of easily exhibiting the desired adhesive strength and transparency, acrylic adhesives are preferable. Furthermore, the adhesive may be a solvent-based adhesive, a solventless adhesive, or an emulsion-based adhesive.

[0082] The acrylic pressure-sensitive adhesive is preferably formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer, a crosslinking agent, and an antistatic agent.

[0083] As the (meth)acrylic acid ester polymer and the crosslinking agent, general crosslinking agents can be used as appropriate, for example, the crosslinking agents described in the second embodiment described later can be used alone or in combination of two or more. The content of the crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 1 part by mass, per 100 parts by mass of the (meth)acrylic acid ester polymer. This allows for the production of a pressure-sensitive adhesive having the desired cohesive strength and coating strength.

[0084] When the antistatic layer 3 is a pressure-sensitive adhesive layer, the antistatic agent can be appropriately selected from those described above and used. The content of the antistatic agent in the pressure-sensitive adhesive composition is preferably 1 to 2,000 parts by mass, more preferably 10 to 1,500 parts by mass, particularly preferably 15 to 1,000 parts by mass, and even more preferably 20 to 500 parts by mass, relative to 100 parts by mass of the (meth)acrylic acid ester polymer. This makes it easier to achieve better antistatic properties.

[0085] If desired, the above-mentioned pressure-sensitive adhesive composition may contain various additives that are commonly used in acrylic pressure-sensitive adhesives, such as ultraviolet absorbers, infrared absorbers, silane coupling agents, photopolymerization initiators, tackifiers, antioxidants, light stabilizers, oxygen absorbers, colorants, surfactants, softeners, fillers, and refractive index adjusters.

[0086] When the antistatic layer 3 is a pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is preferably 1 to 1000 μm, more preferably 5 to 800 μm, and even more preferably 10 to 600 μm, which makes it easier to achieve better antistatic properties.

[0087] The pressure-sensitive adhesive layer can be formed and the pressure-sensitive adhesive composition can be produced in the same manner as in the formation of the pressure-sensitive adhesive layer in the second embodiment described below.

[0088] (4) Substrate When the antistatic layer 3 is a substrate, the substrate may be, for example, provided on the outermost surface on the viewer side of a laminate composed of the light-transmitting imaging section 2, etc., and may have the role of protecting the laminate, or may have the role of supporting other components that make up the aerial image forming devices 10a, 10b.

[0089] The substrate may be formed from a material containing a base material and an antistatic agent. The base material is not particularly limited, but is preferably a resin, and particularly preferably a transparent resin.

[0090] Examples of the resin include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, cellophane, diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyether sulfone, polyetherimide, fluororesin, polyamide, acrylic resin, polyurethane resin, norbornene polymer, cyclic olefin polymer, cyclic conjugated diene polymer, vinyl alicyclic hydrocarbon polymer, etc. These resins may be used alone or in combination of two or more.

[0091] When the antistatic layer 3 is the substrate, the antistatic agent can be appropriately selected from those described above. The content of the antistatic agent in the substrate is preferably 0.1 to 90% by mass, more preferably 0.5 to 85% by mass, and even more preferably 1 to 80% by mass. This makes it easier to achieve better antistatic properties.

[0092] The thickness of the substrate is preferably 15 to 300 μm, more preferably 30 to 200 μm, and even more preferably 90 to 150 μm.

[0093] (5) Light diffusion control section When the antistatic layer 3 is a light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure having a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

[0094] FIG. 3 is a perspective view schematically illustrating the internal structure of the light diffusion control unit 3′. As shown in FIG. 3, the light diffusion control unit 3′ has a louvered, regular internal structure including multiple plate-like regions 31 with a relatively high refractive index within regions 32 with a relatively low refractive index. The regular internal structure of the light diffusion control unit 3′ allows incident light incident on the surface of the light diffusion control unit 3′ within a predetermined range of incident angles to be emitted while being strongly diffused with a predetermined opening angle. On the other hand, when the incident angle is outside the above-mentioned range, the light can be transmitted without being diffused, or can be emitted with less diffusion than incident light within the range of incident angles. The direction perpendicular to the longitudinal direction of the plate-like regions 31 and present on the surface of the light diffusion control unit 3′ opposite the translucent imaging unit 2 (the direction indicated by "D1" in FIG. 3) is referred to as the "first direction."

[0095] 1, the light diffusion control unit 3′ may be provided on the side of the light-transmitting imaging unit 2 opposite to the display unit 1. In this case, the light diffusion control unit 3′ acts to diffuse and transmit light incident on the light-transmitting imaging unit 2 from an external light source, thereby suppressing the effects of ambient light and enabling the aerial image to be clearly viewed.

[0096] 2, the light diffusion control unit 3′ may be provided on the display unit 1 side of the light-transmitting imaging unit 2. In this case, the light diffusion control unit 3′ diffuses and transmits light that forms a ghost image (an image that reflects a real image and is displayed around the aerial image on the aerial image observation plane 4 despite not being displayed on the display surface of the display unit 1), while transmitting light that forms the aerial image with almost no diffusion, thereby suppressing the occurrence of ghost images and enabling the aerial image to be clearly viewed.

[0097] The light diffusion control portions 3' are not particularly limited as long as they have the louver-like regular internal structure described above. From the viewpoint of facilitating the formation of the regular internal structure, the light diffusion control portions 3' are preferably formed by curing a composition for light diffusion control portions containing a high refractive index component, a low refractive index component having a refractive index lower than that of the high refractive index component, and an antistatic agent. In particular, it is preferable that the high refractive index component and the low refractive index component each have one or two polymerizable functional groups.

[0098] The high refractive index component and the low refractive index component may be made of materials generally used for forming a light diffusion control unit. For example, the same materials as those used for the light diffusion control unit 7 in the third embodiment may be used as the material for the light diffusion control unit containing the high refractive index component and the low refractive index component.

[0099] When the antistatic layer 3 is the light diffusion control portion 3', the antistatic agent can be appropriately selected from those described above and used. The content of the antistatic agent in the composition for light diffusion control portion is preferably 1 to 1,000 parts by mass, more preferably 10 to 800 parts by mass, particularly preferably 15 to 600 parts by mass, and even more preferably 20 to 400 parts by mass, relative to 100 parts by mass of the high refractive index component. This makes it easier to achieve better antistatic properties.

[0100] The method for forming the light diffusion control portion 3′ is not particularly limited, and it can be formed by a conventionally known method. For example, it can be formed in the same manner as the method for forming the light diffusion control portion 7 in the third embodiment.

[0101] 3, in the light diffusion control unit 3′, each of the plate-like regions 31 is preferably inclined toward the first direction D1 within the light diffusion control unit 3′, which makes it easier for the aerial image forming devices 10a, 10b according to the first embodiment to suppress the occurrence of ghost images or ambient light and to display brighter aerial images.

[0102] When the plate-like region 31 is inclined as described above, the angle of inclination relative to the thickness direction of the light diffusion control unit 3′ is preferably 0° to 30°, more preferably 1° to 20°, particularly preferably 2° to 15°, and even more preferably 3° to 10°. This makes it easier for the aerial image forming devices 10a and 10b according to the first embodiment to suppress the occurrence of ghost images or ambient light and to display brighter aerial images.

[0103] The light diffusion control unit 3' may have a structure other than the regular internal structure shown in Fig. 3. For example, the plate-like region 31 may be bent partway through the thickness direction of the light diffusion control unit 3'. Furthermore, the light diffusion control unit 3' may have two or more layers stacked together, each layer having a regular internal structure in which the plate-like regions 31 are arranged.

[0104] The thickness of the light diffusion control portion 3' is preferably 1 to 500 μm, more preferably 10 to 400 μm, particularly preferably 50 to 300 μm, and even more preferably 75 to 250 μm, with 100 to 200 μm being particularly preferred. This makes it easier for the aerial image forming device 10a, 10b according to the first embodiment to achieve better antistatic properties, furthermore, makes it easier to suppress the occurrence of ghost images or ambient light, and makes it easier to display brighter aerial images.

[0105] 4. Other Components The aerial image forming devices 10 a and 10 b according to the first embodiment may include multiple antistatic layers 3. For example, the antistatic layers 3 may be stacked on both sides of the light-transmitting imaging unit 2.

[0106] Furthermore, the aerial image forming devices 10a and 10b according to the first embodiment may be provided with at least one of a coating layer other than the antistatic layer 3 (i.e., a layer not containing an antistatic agent), an adhesive layer, a substrate, and a light diffusion control unit.

[0107] Furthermore, the aerial image forming devices 10a and 10b according to the first embodiment preferably include a housing for accommodating and fixing the display unit 1, the light-transmitting image forming unit 2, and the antistatic layer 3 in predetermined positions.

[0108] The material, shape, dimensions, etc. of the housing can be appropriately selected depending on the application and purpose. In particular, it is preferable that the housing is made of a light-blocking material, which can prevent light from the display unit 1 from unintentionally leaking to the outside and can prevent unintentional intrusion of external light into the optical path from the display unit 1 to the light-transmitting imaging unit 2, etc.

[0109] 5. Positional Relationship of Elements When the aerial image forming device 10a, 10b according to the first embodiment includes the light diffusion control unit 3' as the antistatic layer 3, assuming a first direction indicated by "D1" in FIG. 3 and a second direction parallel to a plane perpendicular to both the display surface of the display unit 1 and one side of the light diffusion control unit 3' and existing within one side of the light diffusion control unit 3', it is preferable that the acute angle formed between the first direction and the second direction be greater than or equal to 0° and less than or equal to 90°. Regardless of the acute angle, by considering the angle of incidence on the light diffusion control unit 3' within a plane that includes D1 and is perpendicular to the light diffusion control unit 3', the aerial image forming device 10a, 10b according to the first embodiment can more easily suppress the occurrence of ghost images or ambient light and can more easily display brighter aerial images.

[0110] Furthermore, when the aerial image forming device 10a, 10b according to the first embodiment is provided with a light diffusion control section 3' as the antistatic layer 3 and is provided with the aforementioned retrotransmitting optical element having a dihedral corner reflector array structure, or a retrotransmitting optical element consisting of two layers stacked together, each having multiple reflective surfaces, as the light-transmitting imaging section 2, it is also preferable to satisfy the following conditions.

[0111] First, assume a plane F that is perpendicular to both the surface of the light-transmitting imaging unit 2 opposite the light diffusion control unit 3′ and the display surface of the display unit 1 and that passes through the center point of the light-transmitting imaging unit 2. Also, the width of the light-transmitting imaging unit 2 in a cross section obtained by cutting the light-transmitting imaging unit 2 at the plane F is defined as width W.

[0112] Furthermore, an observation point that exists within the plane F is assumed to satisfy both the following conditions A and B. (Condition A) If the angle between the line segment connecting the observation point and the center point and the surface of the translucent imaging unit 2 opposite to the light diffusion control unit 3' is defined as angle α, and the angle between the plane including the display surface of the display unit 1 and the plane including the surface of the translucent imaging unit 2 opposite to the light diffusion control unit 3' is defined as angle β, the sum of angles α and β is 90°. (Condition B) The distance between the observation point and the center point is 1 to 10 times the width W.

[0113] As a supplementary note, the above condition A means that the position of the observation point is determined depending on the positional relationship between the display unit 1 and the light-transmitting imaging unit 2 in the aerial image forming devices 10a and 10b. For example, for aerial image forming devices 10a and 10b in which the display unit 1 and the light-transmitting imaging unit 2 are disposed so that the angle β is 45°, the angle α related to the observation point is 45°, and for aerial image forming devices 10a and 10b in which the angle β is 60°, the angle α related to the observation point is 30°.

[0114] Furthermore, with regard to the above condition B, the expression "1 to 10 times the width W" means that the observation point only needs to satisfy the condition of any one point within this range. In particular, it is preferable that condition B be "the distance between the observation point and the center point is 3.5 times the width W."

[0115] It is preferable that the elements of the aerial image forming devices 10a, 10b are configured so that, when the aerial image forming devices 10a, 10b are observed from the observation point, the light diffusion control unit 3' simultaneously satisfies the following two conditions: (Condition 1) Of the light that is irradiated from any one point on the display unit 1 and reaches the observation point, the haze value is 60% or less for light that is reflected by both of the two layers that make up the retrotransmissive optical element. (Condition 2) Of the light that is irradiated from any one point on the display unit 1 and reaches the observation point, the haze value is 60% or more for light that is reflected by only one of the two layers that make up the retrotransmissive optical element.

[0116] By satisfying the above conditions, the aerial image forming devices 10a and 10b according to the first embodiment can easily suppress the occurrence of ghost images or ambient light, and can easily display brighter aerial images.

[0117] Here, "reflection occurs in both layers" or "reflection occurs in only one of the two layers" does not refer to physical reflection, but rather to reflection in the sense of changing the direction of travel. Since parallel mirror surfaces are arranged in each layer of a retrotransmissive optical element, which is made up of two layers stacked together, each layer having multiple reflective surfaces, the direction of travel is changed by an odd number of reflections, but not by an even number of reflections. The phrase "reflection occurs" in the above can be rephrased as "reflection occurs an odd number of times, and the direction of travel is changed."

[0118] 6. Manufacturing Method of Aerial Image Forming Device The manufacturing method of the aerial image forming devices 10 a, 10 b according to the first embodiment is not particularly limited. For example, after preparing the display unit 1, the light-transmitting image forming unit 2, and the antistatic layer 3, the display unit 1 is placed in a predetermined position on the housing, and a laminate of the light-transmitting image forming unit 2 and the antistatic layer 3 is placed, thereby obtaining the aerial image forming devices 10 a, 10 b.

[0119] 7. Method of Using the Aerial Image Forming Device The aerial image forming devices 10a and 10b according to the first embodiment can be used as display devices for displaying any image or video in the air. There are no specific limitations on the specific method of use, and they can be used in the same way as conventionally known display devices.

[0120] [Laminated Body According to First Embodiment] The laminated body according to the first embodiment is the aerial image forming device 10 a, 10 b described above, with the display unit 1 omitted. That is, the laminated body according to the first embodiment includes a light-transmitting image forming unit 2 that forms an image at a position on the other surface of light-transmitting image forming unit 2, and an antistatic layer 3 that contains an antistatic agent and is laminated on one surface of the light-transmitting image forming unit 2. Details of the composition, structure, etc. of the light-transmitting image forming unit 2 and the antistatic layer 3 are as described above.

[0121] The laminate according to the first embodiment can be obtained by preparing the light-transmitting image forming unit 2 and the antistatic layer 3 and then laminating them. The laminate according to the first embodiment can also be used to form the aerial image forming devices 10a and 10b according to the first embodiment. That is, the aerial image forming devices 10a and 10b according to the first embodiment can be obtained by placing the display unit 1 at a predetermined position on the laminate according to the first embodiment.

[0122] 4 and 5 are cross-sectional views each showing a schematic example of an aerial image forming device according to a second embodiment. As shown in Fig. 4 and Fig. 5, the aerial image forming devices 10c and 10d according to the second embodiment each include a display unit 1 having a display surface and emitting light from the display surface, a light-transmitting image forming unit 2 disposed on the display surface side of the display unit 1 and transmitting the light to form an image at a position on the side opposite the display unit 1, and a coloring layer 6 containing a coloring component.

[0123] In particular, in the aerial image forming device 10c shown in Fig. 4, the colored layer 6 is laminated on the surface of the translucent imaging unit 2 opposite to the display unit 1. In addition, in the aerial image forming device 10d shown in Fig. 2, the colored layer 6 is laminated on the surface of the translucent imaging unit 2 facing the display unit 1.

[0124] In the aerial image forming devices 10c and 10d according to the second embodiment, the laminate of the light-transmitting imaging section 2 and the colored layer 6 has a color difference ΔE* defined by the CIE 1976 L*a*b* color system relative to a black plate of 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less.

[0125] As described above, the aerial image forming devices 10c and 10d according to the second embodiment include a colored layer 6 containing a coloring component, and satisfy the conditions for the color difference ΔE* and total light transmittance. This allows the portion of the laminate exposed from the housing to blend in appearance with the portion of the housing adjacent to the exposed portion, making it difficult for a viewer to visually recognize the boundary between these portions. This allows the aerial image forming devices 10c and 10d according to the second embodiment to have excellent appearance harmony. To facilitate even better appearance harmony, it is preferable that the colored layer 6 be disposed on the side of the translucent imaging unit 2 opposite the display unit 1 (the viewer's side), as shown in FIG. 4 .

[0126] As described above, in the aerial image forming devices 10c and 10d according to the second embodiment, the color difference ΔE* is 20 or less. However, from the viewpoint of achieving better appearance harmony, ΔE* is preferably 18.5 or less, more preferably 16 or less, particularly preferably 15 or less, and even more preferably 14.5 or less. The lower limit of ΔE* is not particularly limited and may be, for example, 0 or more. However, from the viewpoint of achieving a bright and easily visible aerial image while maintaining excellent appearance harmony, it is preferably 0.01 or more, more preferably 0.1 or more, particularly preferably 1.0 or more, even more preferably 4.0 or more, and especially preferably 7.0 or more. Details of the method for calculating ΔE* and the methods for measuring the various values ​​required for this calculation are described in the test examples below.

[0127] In the aerial image forming devices 10c and 10d according to the second embodiment, the lightness L* of the laminate of the light-transmitting imaging unit 2 and the colored layer 6, as defined by the CIE 1976 L*a*b* color system relative to a black plate, is preferably 1 to 90, more preferably 3 to 60, particularly preferably 6 to 30, even more preferably 8 to 22, and of these, preferably 9 to 17. Furthermore, the absolute value of the chromaticity a*, as defined by the CIE 1976 L*a*b* color system relative to a black plate, is preferably -30 to 30, more preferably -20 to 20, particularly preferably -10 to 10, even more preferably -5 to 5, and of these, preferably -2 to 2. Furthermore, the absolute value of chromaticity b* defined by the CIE 1976 L*a*b* color system relative to a black plate is preferably -30 to 30, more preferably -20 to 20, particularly preferably -10 to 10, even more preferably -6 to 6, and most preferably -3 to 3. This makes it easier to satisfy the above-mentioned ΔE* condition. Details of the methods for measuring lightness L*, chromaticity a*, and chromaticity b* are as described in the tests below.

[0128] Furthermore, in the aerial image forming devices 10c and 10d according to the second embodiment, as described above, the total light transmittance is preferably 10% or more and 100% or less. From the viewpoint of easily achieving superior appearance harmony, the total light transmittance is preferably 91% or less, more preferably 85% or less, particularly preferably 75% or less, even more preferably 65% ​​or less, and of these, preferably 55% or less. From the viewpoint of making the aerial image bright and easily visible while maintaining excellent appearance harmony, the total light transmittance is preferably 20% or more, more preferably 25% or more, particularly preferably 30% or more, even more preferably 35% or more, and of these, preferably 40% or more. Details of the method for measuring the total light transmittance are as described in the test examples below.

[0129] Furthermore, in the aerial image forming devices 10c and 10d according to the second embodiment, the haze value of the laminate of the light-transmitting imaging unit 2 and the colored layer 6 is preferably 0 to 99, more preferably 20 to 97, particularly preferably 40 to 95, even more preferably 50 to 92, and most preferably 60 to 90. This makes it easier to satisfy the total light transmittance requirement described above. Details of the method for measuring the haze value are as described in the test below.

[0130] 1. Display Unit The display unit 1 constituting the aerial image forming devices 10c and 10d according to the second embodiment may be the same as the display unit 1 in the first embodiment. Furthermore, the preferred positional relationship between the display unit 1, the light-transmitting image forming unit 2, and the colored layer 6 is also the same as the positional relationship between the display unit 1, the light-transmitting image forming unit 2, and the antistatic layer 3 in the first embodiment.

[0131] 2. Light-transmitting imaging section The light-transmitting imaging section 2 constituting the aerial image forming devices 10c and 10d according to the second embodiment may be the same as the light-transmitting imaging section 2 in the first embodiment.

[0132] 3. Coloring Layer The coloring layer 6 in the second embodiment is not limited in material or configuration as long as it contains a coloring component and can achieve the aforementioned color difference ΔE* and total light transmittance requirements. For example, the coloring layer 6 is preferably at least one of a coating layer containing a coloring component, a pressure-sensitive adhesive layer containing a coloring component, a substrate containing a coloring component, and a light diffusion control section containing a coloring component. Among these, the coloring layer 6 is preferably at least one of a pressure-sensitive adhesive layer containing a coloring component and a light diffusion control section containing a coloring component. Note that, from the perspective of the SDGs, the material constituting the coloring layer 6 may be a material with a high biomass content, a recyclable or reusable material, or a recycled or reused material.

[0133] (1) Coloring Component The coloring component is not particularly limited and may be, for example, a pigment or a dye. The pigment may be an inorganic pigment or an organic pigment. From the viewpoint of durability of the colored layer 6, inorganic pigments are preferred. The color of the colorant can be appropriately selected to match the color of the surrounding components to which a sense of unity is desired, but generally, a dark or deep color such as black, brown, navy blue, purple, or blue is preferred, and black is particularly preferred.

[0134] Examples of inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments.

[0135] Examples of organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squarium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyrylium-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolinone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, dioxazine-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and threne-based dyes.

[0136] Examples of black pigments include carbon black, copper oxide, iron oxide, manganese dioxide, aniline black, activated carbon, etc. Examples of black dyes include high-concentration vegetable dyes and azo dyes.

[0137] The above pigments and dyes can be mixed appropriately so as to obtain the desired physical properties in the colored layer 6 .

[0138] Among the above colorants, it is preferable to use at least one of carbon black, nigrosine-based black dyes, and chromate-based black dyes, from the viewpoint of easily satisfying the above-mentioned conditions for color difference ΔE* and total light transmittance. Note that the carbon black may or may not have been subjected to a predetermined surface treatment (for example, a solvent-philic treatment).

[0139] The coloring component preferably has an average haze of 0 to 60%, more preferably 0.01 to 45%, particularly preferably 0.5 to 30%, even more preferably 1 to 20%, and most preferably 1 to 10%, which is the average of the haze values ​​at a wavelength of 780 nm and 380 nm when the coloring component is diluted 10,000 times with ethyl acetate. Use of such a coloring component makes it easier to obtain a colored layer that satisfies the above-mentioned conditions for color difference ΔE* and total light transmittance.

[0140] Furthermore, the coloring component is preferably one in which the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, when the coloring component is diluted 10,000 times with ethyl acetate, is 0 to 30 points, more preferably 1 to 24 points, particularly preferably 2 to 18 points, even more preferably 3 to 12 points, and most preferably 4 to 8 points. By using such a coloring component, it becomes easier to obtain a colored layer that satisfies the above-mentioned conditions for color difference ΔE* and total light transmittance.

[0141] The haze value at a wavelength of 780 nm of a solution obtained by diluting the above colorant 10,000 times with ethyl acetate is preferably 0 to 50%, more preferably 0.1 to 30%, particularly preferably 0.5 to 20%, and even more preferably 1 to 10%. Furthermore, the haze value at a wavelength of 380 nm of a solution obtained by diluting the above colorant 10,000 times with ethyl acetate is preferably 0 to 60%, more preferably 0.1 to 40%, particularly preferably 0.5 to 25%, and even more preferably 1 to 15%. Focusing on these haze values ​​serves as an index for identifying colorant components that are likely to satisfy the average haze and difference values ​​for the colorant components described above.

[0142] Furthermore, the standard deviation of the haze value at each wavelength in 5 nm increments in the wavelength range of 380 nm to 780 nm (i.e., 380 nm, 385 nm, 390 nm, ..., 775 nm, 780 nm) of a solution obtained by diluting the above colorant 10,000 times with ethyl acetate is preferably 0 to 10, more preferably 0.1 to 7, particularly preferably 0.2 to 4, and even more preferably 0.3 to 2. By using such a coloring component, it becomes easier to obtain a colored layer that satisfies the above-mentioned conditions for color difference ΔE* and total light transmittance.

[0143] (2) Adhesive Layer When the colored layer 6 in the second embodiment is an adhesive layer, the adhesive layer is preferably used to bond the components constituting the aerial image forming devices 10 c, 10 d together. For example, when the aerial image forming devices 10 c, 10 d include a light diffusion control unit, the adhesive layer as the colored layer 6 is preferably laminated between the light diffusion control unit and the light-transmitting imaging unit 2 to bond them together.

[0144] The adhesive constituting the adhesive layer is not particularly limited. From the viewpoint of facilitating good visibility of the aerial image, it is preferable that the adhesive has transparency. Specific examples of the adhesive include the adhesives described above in the first embodiment, but from the viewpoint of easily exhibiting the desired adhesive strength and transparency, an acrylic adhesive is preferable. Furthermore, the adhesive may be a solvent-based adhesive, a solventless adhesive, or an emulsion-based adhesive.

[0145] The acrylic pressure-sensitive adhesive is preferably formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer and a coloring component, and is particularly preferably formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer, a crosslinking agent, and a coloring component.

[0146] (2-1) (Meth)acrylic Acid Ester Polymer From the viewpoint of easily exhibiting a desired adhesive strength (particularly from the viewpoint of adhesion to the light diffusion control section and the light-transmitting image forming section), the (meth)acrylic acid ester polymer preferably contains a (meth)acrylic acid alkyl ester as a monomer unit constituting the polymer, and particularly preferably contains a (meth)acrylic acid alkyl ester in which the alkyl group has 1 to 20 carbon atoms.

[0147] Examples of (meth)acrylic acid alkyl esters having an alkyl group containing 1 to 20 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, etc. Among these, from the viewpoint of further improving adhesiveness, (meth)acrylic acid esters having an alkyl group containing 1 to 8 carbon atoms are preferred, and it is preferable to use at least one of methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isobornyl (meth)acrylate. These may be used alone or in combination of two or more.

[0148] The (meth)acrylic acid ester polymer preferably contains 50 to 99.9 mass% of (meth)acrylic acid alkyl esters having an alkyl group containing 1 to 20 carbon atoms as monomer units constituting the polymer, more preferably 60 to 99 mass%, particularly preferably 70 to 96 mass%, even more preferably 75 to 92 mass%, and most preferably 80 to 88 mass%. This makes it easier to exhibit suitable adhesive properties, and results in excellent adhesion, particularly to light diffusion control sections and light-transmitting image formation sections. Furthermore, suitable amounts of other monomer components, such as reactive functional group-containing monomers, can be incorporated into the (meth)acrylic acid ester polymer.

[0149] It is also preferable that the (meth)acrylic acid ester polymer contains, as a monomer unit constituting the polymer, a reactive functional group-containing monomer having a reactive functional group in the molecule. In particular, when the pressure-sensitive adhesive composition contains a crosslinking agent, the reactive functional group of the reactive functional group-containing monomer reacts with the crosslinking agent, making it easier to control the cohesive strength of the resulting pressure-sensitive adhesive. This makes it easier for the resulting pressure-sensitive adhesive layer to exhibit the desired adhesive strength.

[0150] Preferred examples of reactive functional group-containing monomers include monomers having a hydroxy group in the molecule (hydroxy group-containing monomers), monomers having a carboxy group in the molecule (carboxy group-containing monomers), and monomers having an amino group in the molecule (amino group-containing monomers). Among these, hydroxy group-containing monomers are preferred. These reactive functional group-containing monomers may be used alone or in combination of two or more.

[0151] Examples of hydroxy group-containing monomers include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Of these, it is preferable to use 2-hydroxyethyl (meth)acrylate. These may be used alone or in combination of two or more.

[0152] Examples of the carboxy group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, etc. These may be used alone or in combination of two or more.

[0153] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, n-butylaminoethyl (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0154] The (meth)acrylic acid ester polymer preferably contains 0.1 to 50 mass %, more preferably 1 to 40 mass %, particularly preferably 4 to 30 mass %, even more preferably 8 to 25 mass %, and of these, preferably 12 to 20 mass %, of the reactive functional group-containing monomer as a monomer unit constituting the polymer. This improves the adhesiveness of the resulting pressure-sensitive adhesive, making it easier for the pressure-sensitive adhesive layer to exhibit the desired adhesive strength and resulting in excellent adhesion, particularly to the light diffusion control section and the light-transmitting image formation section.

[0155] The (meth)acrylic acid ester polymer may be a copolymer of the above-mentioned (meth)acrylic acid alkyl ester, reactive functional group-containing monomer, etc. with other monomers. As the other monomer, a monomer that does not contain a reactive functional group is preferred so as not to inhibit the above-mentioned action of the reactive functional group-containing monomer. Examples of such monomers include (meth)acrylic acid alkoxyalkyl esters such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, vinyl acetate, and styrene. These may be used alone or in combination of two or more. Furthermore, the polymerization mode of the polymer may be a random copolymer or a block copolymer. Furthermore, the polymer may be used alone or in combination of two or more.

[0156] The weight-average molecular weight of the (meth)acrylic acid ester polymer is preferably 100,000 to 3,000,000, more preferably 200,000 to 2,400,000, particularly preferably 300,000 to 1,800,000, and even more preferably 400,000 to 1,200,000, with 500,000 to 900,000 being preferred. This allows the resulting pressure-sensitive adhesive layer to easily exhibit the desired adhesive strength, and to exhibit excellent adhesion, particularly to the light diffusion control section and the light-transmitting image forming section. The weight-average molecular weight measured in this specification refers to a value calculated in terms of standard polystyrene, measured by gel permeation chromatography (GPC).

[0157] (2-2) Crosslinking Agent The crosslinking agent may be any that reacts with the reactive functional groups of the (meth)acrylic acid ester polymer, and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. Among the above, it is preferable to use an isocyanate-based crosslinking agent that has excellent reactivity with hydroxy groups and carboxy groups, or an epoxy-based crosslinking agent that has excellent reactivity with carboxy groups. The crosslinking agents may be used alone or in combination of two or more.

[0158] The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; and biuret and isocyanurate forms thereof, as well as adducts thereof that are reaction products with low-molecular-weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified aromatic polyisocyanates, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate, are preferred from the viewpoint of reactivity with hydroxy groups.

[0159] Examples of epoxy crosslinking agents include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine, etc. Among these, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane is preferred from the viewpoint of reactivity with carboxy groups.

[0160] The content of the crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, particularly preferably 0.08 to 1 part by mass, even more preferably 0.12 to 0.7 parts by mass, and especially preferably 0.15 to 0.4 parts by mass, relative to 100 parts by mass of the (meth)acrylic acid ester polymer. This makes it easy for the resulting pressure-sensitive adhesive to have favorable physical properties, adhesive strength, etc., and to have excellent adhesion, particularly to the light diffusion control section and the light-transmitting image formation section.

[0161] (2-3) Coloring Component When the coloring layer 6 is a pressure-sensitive adhesive layer, the coloring component can be appropriately selected from those described above. The content of the coloring component in the pressure-sensitive adhesive composition is preferably 0.01 to 20 parts by mass, particularly preferably 0.05 to 15 parts by mass, and even more preferably 0.10 to 10 parts by mass, and of these, preferably 0.20 to 5 parts by mass, per 100 parts by mass of the (meth)acrylic acid ester polymer. This makes it easier to achieve better appearance harmony.

[0162] (2-4) Various Additives If desired, various additives commonly used in acrylic pressure-sensitive adhesives, such as ultraviolet absorbers, infrared absorbers, silane coupling agents, photopolymerization initiators, tackifiers, antioxidants, light stabilizers, oxygen absorbers, rust inhibitors, surfactants, softeners, fillers, refractive index adjusters, and antistatic agents, may be added to the pressure-sensitive adhesive composition described above.

[0163] (2-5) Preparation of Pressure-Sensitive Adhesive Composition The pressure-sensitive adhesive composition described above can be prepared by mixing the (meth)acrylic acid ester polymer, the crosslinking agent, the coloring component, and other additives.

[0164] The (meth)acrylic acid ester polymer can be produced by polymerizing a mixture of monomer units constituting the polymer using a conventional radical polymerization method. Polymerization of the (meth)acrylic acid ester polymer can be carried out by solution polymerization or the like, optionally using a polymerization initiator. Examples of polymerization solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more of these may be used in combination. Examples of polymerization initiators include azo compounds and organic peroxides, and two or more of these may be used in combination. In the polymerization step, the weight-average molecular weight of the resulting polymer can be adjusted by adding a chain transfer agent such as 2-mercaptoethanol.

[0165] After the (meth)acrylic acid ester polymer is obtained, a crosslinking agent, a coloring component, and other additives as desired are added to the solution of the (meth)acrylic acid ester polymer, and the mixture is thoroughly mixed to obtain a pressure-sensitive adhesive composition (coating solution) diluted with a solvent.

[0166] Examples of dilution solvents that can be used to dilute the pressure-sensitive adhesive composition to prepare a coating solution include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; alcohols such as methanol, ethanol, propanol, butanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; and cellosolve-based solvents such as ethyl cellosolve.

[0167] The concentration and viscosity of the coating solution prepared in this manner are not particularly limited as long as they are within a range that allows coating, and can be appropriately selected depending on the situation. For example, the pressure-sensitive adhesive composition is diluted to a concentration of 10 to 40 mass %. Note that the addition of a dilution solvent or the like is not a necessary condition for obtaining the coating solution, and as long as the pressure-sensitive adhesive composition has a viscosity that allows coating, the addition of a dilution solvent is not necessary.

[0168] (2-6) Formation of Pressure-Sensitive Adhesive Layer The pressure-sensitive adhesive layer is preferably made of a pressure-sensitive adhesive obtained by crosslinking the above-mentioned pressure-sensitive adhesive composition. Crosslinking of the pressure-sensitive adhesive composition can usually be carried out by heat treatment. This heat treatment can also serve as a drying treatment for volatilizing diluent solvents and the like from the coating layer of the pressure-sensitive adhesive composition applied to the desired object.

[0169] The heating temperature for the heat treatment is preferably 50 to 150° C., and particularly preferably 70 to 120° C. The heating time is preferably 10 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes.

[0170] After the heat treatment, a curing period of about 1 to 2 weeks may be provided at room temperature (e.g., 23°C, 50% RH), if necessary. If this curing period is required, the pressure-sensitive adhesive is formed after the curing period has elapsed. If no curing period is required, the pressure-sensitive adhesive is formed after the heat treatment has been completed.

[0171] The above heat treatment (and curing) allows the (meth)acrylic acid ester polymer to be sufficiently crosslinked via the crosslinking agent.

[0172] (2-7) Physical Properties of the Adhesive Layer When the colored layer 6 in the second embodiment is an adhesive layer, the total light transmittance of the adhesive layer is preferably 10 to 99%, more preferably 15 to 98%, and even more preferably 20 to 95%. When the total light transmittance of the colored layer 6 alone is within these ranges, the aerial image forming devices 10c and 10d according to the second embodiment, which are configured using the colored layer 6, are more likely to satisfy the total light transmittance and color difference ΔE* requirements described above. Details of the method for measuring the total light transmittance are as described in the test examples below.

[0173] When the colored layer 6 is a pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is preferably 1 to 500 μm, more preferably 2 to 300 μm, particularly preferably 4 to 200 μm, even more preferably 8 to 100 μm, and most preferably 12 to 50 μm. This facilitates achieving better appearance harmony. In particular, it facilitates obtaining a colored layer that satisfies the aforementioned conditions for color difference ΔE* and total light transmittance, and also provides excellent adhesion to the light diffusion control section and the light-transmitting image forming section.

[0174] (3) Light diffusion control section When the colored layer 6 in the second embodiment is a light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

[0175] FIG. 6 is a perspective view schematically illustrating the internal structure of the light diffusion control unit 6′. As shown in FIG. 6, the light diffusion control unit 6′ has a louvered, regular internal structure including a plurality of plate-like regions 61 with a relatively high refractive index within a region 62 with a relatively low refractive index. The direction perpendicular to the longitudinal direction of the plate-like regions 61 and present on the surface of the light diffusion control unit 6′ opposite the translucent imaging unit 2 (the direction indicated by “D1” in FIG. 6) is defined as the “first direction.” The function of the light diffusion control unit 6′ is similar to that of the light diffusion control unit 3′ shown in FIG. 3.

[0176] The light diffusion control unit 6' may be provided on the side of the translucent imaging unit 2 opposite to the display unit 1, as shown in Fig. 4. Alternatively, the light diffusion control unit 6' may be provided on the side of the translucent imaging unit 2 facing the display unit 1, as shown in Fig. 5. The effect of the light diffusion control unit 6' obtained in these positional relationships is similar to that of the light diffusion control unit 3' in the first embodiment.

[0177] The light diffusion control unit 6′ can be made of the same material as the light diffusion control unit 7 in the third embodiment. The light diffusion control unit 6′ can be formed by the same method as the light diffusion control unit 7 in the third embodiment.

[0178] When the colored layer 6 is the light diffusion control portion 6', the coloring component can be appropriately selected from those described above and used. The content of the coloring component in the composition for light diffusion control portion is preferably 0.001 to 10 parts by mass, more preferably 0.004 to 6 parts by mass, particularly preferably 0.008 to 3 parts by mass, and even more preferably 0.01 to 2 parts by mass, relative to 100 parts by mass of the high refractive index component. This makes it easier to satisfy the above-mentioned conditions for color difference ΔE* and total light transmittance, and makes it easier to achieve better appearance harmony.

[0179] In the light diffusion control unit 6', the plate-like region 61 is preferably inclined, similar to the light diffusion control unit 3' in the first embodiment. In this case, the angle of inclination relative to the thickness direction of the light diffusion control unit 6' is preferably 0° to 30°, more preferably 1° to 25°, particularly preferably 2° to 20°, and even more preferably 3° to 10°. This makes it easier for the aerial image forming devices 10c and 10d according to the second embodiment to suppress the occurrence of ghost images or ambient light and to display brighter aerial images.

[0180] The light diffusion control unit 6' may be bent in the middle of the thickness direction, similar to the light diffusion control unit 3' in the first embodiment, and may be formed by stacking two or more layers of a regular internal structure in which plate-shaped regions 61 are arranged.

[0181] The thickness of the light diffusion control portion 6' is preferably 1 to 500 μm, more preferably 10 to 300 μm, particularly preferably 50 to 250 μm, and even more preferably 80 to 200 μm, which makes it easier for the aerial image forming devices 10c and 10d according to the second embodiment to achieve better harmony in appearance, furthermore, makes it easier to suppress the occurrence of ghost images or ambient light, and makes it easier to display brighter aerial images.

[0182] (4) Other Components When the colored layer 6 in the second embodiment is a coating layer, the coating layer is preferably laminated on the side of the light-transmitting image forming unit 2 opposite the display unit 1, as shown in Fig. 1, and serves to protect the surface of the light-transmitting image forming unit 2. The coating layer may be formed on a substrate, and in this case, a coating film including the coating layer and the substrate may be laminated on the light-transmitting image forming unit 2.

[0183] The coating layer is preferably formed by curing a coating composition containing, for example, an active energy ray-curable component, the above-mentioned coloring component, and other additives.

[0184] Furthermore, when the colored layer 6 in the second embodiment is a substrate, the substrate may be, for example, provided on the outermost surface on the viewer side of a laminate composed of the translucent imaging section 2, etc., and may have the role of protecting the laminate, or may have the role of supporting other components that make up the aerial image forming device 10c, 10d.

[0185] The substrate may be formed from a material containing a base material and a coloring component. The base material is not particularly limited, but is preferably a resin, and particularly preferably a transparent resin.

[0186] 4. Other Components The aerial image forming devices 10c and 10d according to the second embodiment may include a plurality of colored layers 6. For example, colored layers 6 may be stacked on both sides of the light-transmitting imaging unit 2.

[0187] Furthermore, the aerial image forming devices 10c and 10d according to the second embodiment may additionally include at least one of a coating layer (not containing a coloring component), an adhesive layer, a substrate, and a light diffusion control section other than the colored layer 6. In particular, when the colored layer 6 is an adhesive layer, it is preferable that the aerial image forming devices 10c and 10d include other components such as a light diffusion control section, and that the colored layer 6 as an adhesive layer serves to tightly fix these components together.

[0188] Furthermore, the aerial image forming devices 10c and 10d according to the second embodiment preferably include a housing for accommodating and fixing the display unit 1, the light-transmitting image forming unit 2, and the colored layer 6 in predetermined positions.

[0189] The material, shape, dimensions, etc. of the housing can be appropriately selected depending on the application and purpose. In particular, it is preferable that the housing is made of a light-blocking material, which can prevent light from the display unit 1 from unintentionally leaking to the outside and can prevent unintentional intrusion of external light into the optical path from the display unit 1 to the light-transmitting imaging unit 2, etc.

[0190] 5. Positional Relationship of Each Element When the aerial image forming devices 10c and 10d according to the second embodiment include a light diffusion control section 6′ as the colored layer 6, it is preferable that the condition regarding the “acute angle between the first direction and the second direction” be satisfied, as in the first embodiment.

[0191] Furthermore, when the aerial image forming devices 10c and 10d of the second embodiment have a light diffusion control section 6' as the colored layer 6 and have, as the light-transmitting imaging section 2, the aforementioned retrotransmitting optical element having a two-sided corner reflector array structure, or a retrotransmitting optical element consisting of two layers stacked together each having multiple reflective surfaces, it is preferable that each element of the aerial image forming devices 10c and 10d be configured so as to simultaneously satisfy "(Condition 1)" and "(Condition 2)," as in the first embodiment.

[0192] 6. Manufacturing Method of Aerial Image Forming Device The manufacturing method of the aerial image forming devices 10c and 10d according to the second embodiment is not particularly limited. For example, after preparing the display unit 1, the light-transmitting image forming unit 2, and the colored layer 6, the display unit 1 is placed at a predetermined position on the housing, and a laminate of the light-transmitting image forming unit 2 and the colored layer 6 is placed, thereby obtaining the aerial image forming devices 10c and 10d.

[0193] 7. Method of Using the Aerial Image Forming Device The aerial image forming devices 10c and 10d according to the second embodiment can be used as display devices for displaying any image or video in the air. The specific method of use is not limited, and they can be used in the same way as conventionally known display devices.

[0194] [Laminated Body According to Second Embodiment] The laminated body according to the second embodiment is a laminated body obtained by omitting the display unit 1 from the aerial image forming devices 10c and 10d described above. That is, the laminated body according to the second embodiment includes a light-transmitting image forming unit 2 that forms an image at a position on the other surface of light-transmitting image forming unit 2, and a colored layer 6 containing a coloring component that is laminated on one surface of the light-transmitting image forming unit 2. Details of the composition, structure, etc. of the light-transmitting image forming unit 2 and the colored layer 6 are as described above.

[0195] The laminate according to the second embodiment can be obtained by preparing the light-transmitting image forming unit 2 and the colored layer 6 and then laminating them. The laminate according to the second embodiment can also be used to form the aerial image forming devices 10c and 10d according to the second embodiment. That is, the aerial image forming devices 10c and 10d according to the second embodiment can be obtained by placing the display unit 1 at a predetermined position on the laminate according to the second embodiment.

[0196] 7 to 9 are cross-sectional views each showing a schematic example of an aerial image forming device according to a third embodiment. As shown in all of Figures 7 to 9, aerial image forming devices 10e, 10f, and 10g according to the third embodiment include a display unit 1 having a display surface and emitting light from the display surface, a light-transmitting imaging unit 2 disposed on the display surface side of the display unit 1, and a light diffusion control unit 7 laminated on the side of the light-transmitting imaging unit 2 opposite the display unit 1 or on the side of the light-transmitting imaging unit 2 facing the display unit 1.

[0197] Here, the light-transmitting image forming unit 2 transmits light originating from the display surface and forms an image at a position on the surface side opposite the display unit 1. The light diffusion control unit 7 diffuses or transmits light incident into the light diffusion control unit 7 depending on the angle of incidence, and has a regular louver-like internal structure that includes a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

[0198] The aerial image forming device according to the third embodiment further includes a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control section 7 contains an ultraviolet absorber.

[0199] The aerial image forming devices 10e and 10f shown in FIGS. 7 and 8 do not have a weather-resistant layer, and the light diffusion control section 7 contains an ultraviolet absorbing agent.

[0200] 9 includes a weather-resistant layer 8 on the surface of the translucent imaging unit 2 opposite the light diffusion control unit 7. When the aerial image forming device according to the third embodiment includes the weather-resistant layer 8, the position of the weather-resistant layer 8 is not limited to that shown in FIG. 3 and may be located in other positions. That is, the weather-resistant layer 8 may be located on the surface of the translucent imaging unit 2 opposite the light diffusion control unit 7, on the surface of the light diffusion control unit 7 opposite the translucent imaging unit 2, or at least one position between the translucent imaging unit 2 and the light diffusion control unit 7.

[0201] Examples of the weather-resistant layer 8 include at least one of a coating layer containing an ultraviolet absorber, a pressure-sensitive adhesive layer containing an ultraviolet absorber, an adhesive layer containing an ultraviolet absorber, and a substrate containing an ultraviolet absorber.

[0202] As described above, the aerial image forming devices 10e, 10f, and 10g according to the third embodiment have a light diffusion control unit 7 that contains an ultraviolet absorber or a weather-resistant layer that contains an ultraviolet absorber. Therefore, even if a laminate including the light diffusion control unit 7 is exposed to ultraviolet light, such as sunlight, for a long period of time, the effect of the ultraviolet absorber on the light diffusion control unit 7 is significantly reduced. This suppresses photodegradation of the light diffusion control unit 7, making the light diffusion control unit 7 less likely to yellow. As a result, the aerial image forming devices 10e, 10f, and 10g according to the third embodiment have excellent weather resistance and enable good visibility of the aerial image.

[0203] Furthermore, in aerial image forming devices 10e and 10g (FIGS. 7 and 9) in which the light diffusion control unit 7 is stacked on the side of the light-transmitting imaging unit 2 facing the display unit 1, the occurrence of ghost images can be effectively suppressed. This effect is described below.

[0204] FIG. 10 is a perspective view schematically illustrating the internal structure of the light diffusion control unit 7. As shown in FIG. 10, the light diffusion control unit 7 has a louvered, regular internal structure including a plurality of plate-like regions 71 with a relatively high refractive index within a region 72 with a relatively low refractive index. The direction perpendicular to the longitudinal direction of the plate-like regions 71 and present on the surface of the light diffusion control unit 7 opposite the translucent imaging unit 2 (the direction indicated by "D1" in FIG. 10) is defined as the "first direction." The function of the light diffusion control unit 6' is similar to that of the light diffusion control unit 3' shown in FIG. 3.

[0205] In the aerial image forming devices 10e and 10g according to the third embodiment, when a desired image (real image) is displayed on the display surface of the display unit 1, an image (aerial image) formed by the real image being focused in the air can be seen at the position indicated by reference numeral "4" in Fig. 7 when viewed from a predetermined observation point 5. In this specification, the surface indicated by reference numeral "4" will be referred to as the "aerial image observation surface."

[0206] In conventional aerial image forming devices, an image known as a ghost image may also be displayed along with the aerial image. To suppress the occurrence of such ghost images, optical elements that block only the light that contributes to the formation of the ghost image are sometimes used. However, because these optical elements block a portion of the light emitted from the display unit 1, the brightness of the aerial image is reduced, making it difficult for the viewer to view the aerial image.

[0207] In contrast, the aerial image forming devices 10e and 10g according to the third embodiment are equipped with the light diffusion control unit 7, and are therefore able to effectively suppress the occurrence of ghost images while maintaining sufficient brightness of the aerial image. As will be explained below, this effect is presumed to be due to the action of the light diffusion control unit 7. However, this effect is not limited to this action, and the possibility of other effects also exists.

[0208] FIG. 11 is a diagram for explaining the action of the light diffusion control unit 7, and in particular, a diagram for explaining the relationship between the optical characteristics of the light diffusion control unit 7 and the light that forms the aerial image and the ghost image.

[0209] As described above, the light diffusion control unit 7 diffuses and transmits light incident within a predetermined incident angle range, and transmits light incident outside this incident angle range with almost no diffusion. The graph in FIG. 11 shows the relationship between the incident angle of light incident on the light diffusion control unit 7 and the haze value. Specifically, it shows that for light incident from an incident angle range of approximately −10° to approximately 10°, the haze value exceeds 80% (i.e., the light is diffused and transmitted). On the other hand, it shows that for light incident from an incident angle range of approximately −70° to approximately −20°, the haze value is approximately 15% (i.e., the light is transmitted with almost no diffusion). The incident angle at which the haze value fluctuates significantly (near −15° in FIG. 11 ) is sometimes referred to as the “threshold value.”

[0210] Here, the "haze value" mentioned above differs from ordinary "haze" in that it is a measurement value obtained by placing a predetermined distance between the integrating sphere opening and the sample and varying the angle of incidence onto the sample. In the measurements herein, the predetermined distance is set to 20 mm, but the value is not particularly limited as long as it allows for confirmation of the straight transmission / diffuse transmission of incident light.

[0211] In the aerial image forming devices 10e and 10g according to the third embodiment, the light diffusion controller 7 exhibiting the above-described optical characteristics is located between the display unit 1 and the translucent imaging unit 2. This allows the light for forming the aerial image to reach the translucent imaging unit 2 effectively, while allowing the light for forming the ghost image to reach the translucent imaging unit 2 in a diffused state. This allows the viewer to clearly view the aerial image while making it difficult to view the ghost image. Furthermore, because the light diffusion controller 7 controls the diffusion of light rather than blocking light, it is possible to display the aerial image with sufficient brightness while suppressing the occurrence of ghost images.

[0212] Furthermore, by appropriately adjusting the type of light diffusion control unit 7 and the stacking state with the light-transmitting imaging unit 2, etc., and adjusting the threshold value to be located between the range of incident angles of light for forming an aerial image and the range of incident angles of light for forming a ghost image, as shown in Figure 5, a better effect can be achieved.

[0213] Furthermore, in an aerial image forming device 10f (FIG. 8) in which the light diffusion control unit 7 is stacked on the side of the light-transmitting imaging unit 2 opposite the display unit 1, the influence of ambient light can be effectively suppressed. This effect is described below.

[0214] As a result of various studies, the inventors have speculated that the above-mentioned ambient light is caused by light (hereinafter sometimes referred to as "return light") that is incident on the light-transmitting imaging unit 2 from an external light source and returns in the direction of the viewer. In particular, when the light-transmitting imaging unit 2 is a retrotransmitting optical element (described later), the inventors speculated that such return light is light that is incident on the interior of the retrotransmitting optical element from an external light source, has its emission direction changed significantly within the retrotransmitting optical element, and is emitted from the surface on the viewer side.

[0215] The aerial image forming device 10f according to the third embodiment is configured such that the light diffusion control unit 7 is provided on the viewer-facing surface of the light-transmitting imaging unit 2, so that light incident on the light-transmitting imaging unit 2 from an external light source is diffused and transmitted through the light diffusion control unit 7. This makes it possible to suppress color breakup while blurring the return light, improving visibility. On the other hand, the light originating from the display unit 1 is transmitted straight through the light diffusion control unit 7, allowing the aerial image to be clearly displayed. As a result, the aerial image forming device 10f according to the third embodiment can suppress the return light and reduce the effects of ambient light, thereby enabling the aerial image to be clearly viewed.

[0216] 1. Display Unit The display unit 1 constituting the aerial image forming devices 10e, 10f, and 10g according to the third embodiment may be the same as the display unit 1 in the first embodiment. Furthermore, the preferred positional relationship between the display unit 1, the light diffusion control unit 7, the light-transmitting image forming unit 2, and the weather-resistant layer 8 is also the same as the positional relationship between the display unit 1, the light-transmitting image forming unit 2, and the antistatic layer 3 in the first embodiment.

[0217] 2. Light-transmitting imaging section The light-transmitting imaging section 2 constituting the aerial image forming devices 10e, 10f, and 10g according to the third embodiment may be the same as the light-transmitting imaging section 2 in the first embodiment.

[0218] 3. Light Diffusion Control Unit The light diffusion control unit 7 constituting the aerial image forming devices 10e, 10f, and 10g according to the third embodiment is not particularly limited as long as it has the above-described louver-like regular internal structure.

[0219] From the viewpoint of facilitating the formation of the regular internal structure, it is preferable that the light diffusion control parts 7 are formed by curing a composition for light diffusion control parts containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component. In particular, it is preferable that the high refractive index component and the low refractive index component each have one or two polymerizable functional groups.

[0220] Furthermore, when the light diffusion control portion 7 contains an ultraviolet absorber, the composition for the light diffusion control portion preferably further contains an ultraviolet absorber.

[0221] From the perspective of the SDGs, the material that constitutes the light diffusion control unit 7 may be a material with a high biomass content, a material that can be recycled or reused, or a recycled or reused material.

[0222] (1) High Refractive Index Component Preferred examples of the high refractive index component include (meth)acrylic acid esters containing an aromatic ring, and particularly preferred are (meth)acrylic acid esters containing multiple aromatic rings. Examples of (meth)acrylic acid esters containing multiple aromatic rings include biphenyl (meth)acrylate, naphthyl (meth)acrylate, anthracyl (meth)acrylate, benzylphenyl (meth)acrylate, biphenyloxyalkyl (meth)acrylate, naphthyloxyalkyl (meth)acrylate, anthracyloxyalkyl (meth)acrylate, benzylphenyloxyalkyl (meth)acrylate, and the like, and those partially substituted with halogen, alkyl, alkoxy, alkyl halide, or the like. Among these, biphenyl (meth)acrylate is preferred from the viewpoint of facilitating the formation of a good regular internal structure, and specifically, o-phenylphenoxyethyl acrylate, o-phenylphenoxyethoxyethyl acrylate, and the like are preferred.

[0223] The molecular weight of the high refractive index component is preferably 150 to 2500, particularly preferably 200 to 1500, and even more preferably 250 to 1000. This facilitates the formation of a light diffusion control section 7 having a desired regular internal structure. Note that, if the theoretical molecular weight of the high refractive index component can be determined based on its molecular structure, the molecular weight of the high refractive index component refers to this theoretical molecular weight. On the other hand, if the theoretical molecular weight is difficult to determine because the high refractive index component is, for example, a polymer component, the molecular weight of the high refractive index component refers to the weight-average molecular weight obtained as a value converted into standard polystyrene measured by gel permeation chromatography (GPC). Note that, in this specification, the measurement method for weight-average molecular weight refers to the value converted into standard polystyrene measured by the GPC method.

[0224] The refractive index of the high refractive index component is preferably 1.45 to 1.70, more preferably 1.50 to 1.65, particularly preferably 1.54 to 1.62, and even more preferably 1.56 to 1.59. This makes it easier to form light diffusion control parts 7 having a desired regular internal structure. Note that the refractive index in this specification means the refractive index of a predetermined component before curing the composition for light diffusion control part, and this refractive index is measured in accordance with JIS K0062:1992.

[0225] The content of the high refractive index component in the composition for light diffusion control portions is preferably 25 to 400 parts by mass, more preferably 50 to 350 parts by mass, particularly preferably 75 to 300 parts by mass, and even more preferably 100 to 200 parts by mass, relative to 100 parts by mass of the low refractive index component. This ensures that the regions derived from the high refractive index component and the regions derived from the low refractive index component are present in a desired ratio in the regular internal structure of the light diffusion control portions 7 to be formed, making it easier to form the desired regular internal structure.

[0226] (2) Low refractive index component Preferred examples of the low refractive index component include urethane (meth)acrylate, (meth)acrylic polymers having (meth)acryloyl groups in their side chains, (meth)acryloyl group-containing silicone resins, and unsaturated polyester resins. Among these, it is particularly preferable to use urethane (meth)acrylate because it is easy to form a good regular internal structure. More specifically, it is preferable to use urethane (meth)acrylate formed from (a) a compound containing at least two isocyanate groups, (b) a polyalkylene glycol, and (c) a hydroxyalkyl (meth)acrylate.

[0227] Preferred examples of the (a) compound containing at least two isocyanate groups include aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and biurets and isocyanurates thereof, as well as adducts which are reaction products with low-molecular-weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, alicyclic polyisocyanates are preferred, and alicyclic diisocyanates are particularly preferred.

[0228] Preferred examples of the polyalkylene glycol (b) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol, etc., and among these, polypropylene glycol is preferred. The weight-average molecular weight of the polyalkylene glycol (b) is preferably 2,300 to 19,500, more preferably 3,000 to 14,300, and even more preferably 4,000 to 12,300.

[0229] Preferred examples of the (c) hydroxyalkyl(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 3-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate, and among these, 2-hydroxyethyl(meth)acrylate is preferred.

[0230] The synthesis of a urethane (meth)acrylate using the above-mentioned components (a) to (c) as materials can be carried out according to a conventional method. In this case, from the viewpoint of efficiently synthesizing the urethane (meth)acrylate, the blending ratio of components (a) to (c) is preferably component (a):component (b):component (c)=1-5:1:1-5, and particularly preferably 1-3:1:1-3.

[0231] The weight average molecular weight of the low refractive index component is preferably 3,000 to 20,000, particularly preferably 5,000 to 15,000, and further preferably 7,000 to 13,000. This makes it easier to form the light diffusion control parts 7 having a desired regular internal structure.

[0232] The refractive index of the low refractive index component is preferably 1.30 to 1.59, more preferably 1.38 to 1.50, particularly preferably 1.42 to 1.49, and even more preferably 1.46 to 1.48 or less, which makes it easier to form the light diffusion control portion 7 having a desired regular internal structure.

[0233] (3) Ultraviolet absorber Examples of ultraviolet absorbers include 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-amyl-5'-isobutylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-isobutyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-isobutyl-5'-propylphenyl)-5-chlorobenzotriazole, 2'-hydroxyphenyl-5-chlorobenzotriazole-based ultraviolet absorbers such as 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; 2'-hydroxyphenylbenzotriazole-based ultraviolet absorbers such as 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2',4,4'-tetrahydroxybenzophenone ,2'-dihydroxybenzophenone-based ultraviolet absorbers; 2-hydroxybenzophenone-based ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone; salicylate ester-based ultraviolet absorbers such as phenyl salicylate and 4-tert-butyl-phenyl-salicylate; cyanoacrylate-based ultraviolet absorbers such as 2-ethyl-hexyl-2-cyano-3,3-diphenylacrylate, ethyl-2-cyano-3,3-diphenylacrylate, and octyl-2-cyano-3,3-diphenylacrylate; 2-( Examples of such ultraviolet absorbers include triazine-based ultraviolet absorbers such as 4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3-5-triazine, 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, and tris(hydroxyphenyl)triazine; and reactive ultraviolet absorbers in which an acryloyl group or a methacryloyl group is introduced into a benzotriazole skeleton.These may be used alone or in combination of two or more.

[0234] The content of the ultraviolet absorber in the composition for light diffusion control portion is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 1 part by mass, particularly preferably 0.03 to 0.5 parts by mass, and even more preferably 0.06 to 0.2 parts by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This makes it easier to achieve excellent weather resistance.

[0235] (4) Other Additives The composition for light diffusion control portion described above may contain other additives in addition to the high refractive index component and the low refractive index component. Examples of the other additives include a polyfunctional monomer, a photopolymerization initiator, an antioxidant, a light stabilizer, an antistatic agent, a polymerization accelerator, a polymerization inhibitor, an infrared absorber, a plasticizer, a diluting solvent, and a leveling agent.

[0236] Among the above, it is preferable that the composition for controlling light diffusion contains a light stabilizer. Examples of light stabilizers include hindered amine light stabilizers, benzophenone light stabilizers, and benzotriazole light stabilizers. Among these, it is preferable to use a hindered amine light stabilizer from the viewpoint of easily achieving excellent weather resistance. These light stabilizers may be used alone or in combination of two or more.

[0237] The content of the light stabilizer in the composition for controlling light diffusion is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component, which makes it easier to achieve excellent weather resistance.

[0238] Among the above, it is also preferable that the composition for light diffusion control portion contains a polyfunctional monomer. As the polyfunctional monomer, it is particularly preferable to use a polyfunctional (meth)acrylate-based monomer. As an example of the polyfunctional (meth)acrylate-based monomer, the polyfunctional (meth)acrylate-based monomer used as the material of the coating layer in the first embodiment can be used.

[0239] The content of the polyfunctional monomer in the composition for light diffusion control portion is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component, which makes it easier to achieve excellent weather resistance.

[0240] Among the above, it is also preferable that the composition for light diffusion control portion contains an antioxidant. Examples of the antioxidant include hindered phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants, and among these, hindered phenol-based antioxidants are preferred.

[0241] Examples of hindered phenol-based antioxidants include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5 -di-t-butyl-4-hydroxyphenyl)propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydroxycinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)1,3,5-triazine, 2,4-bis[(octylthio)methyl]-o- Resole, 2,6-di-t-butyl-p-cresol, 4,4'-butylidenebis-(6-t-butyl-3-methylphenol), 2,2'-methylenebis-(4-methyl-6-t-butylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 2,6-di-t-butyl-4-ethylphenol, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H ,5H)trione, isooctyl (3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydroxycinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butyl) Examples of suitable hydroxybenzyl compounds include 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione, and isooctyl(3,5-di-t-butyl-4-hydroxyphenyl)propionate. These compounds may be used alone or in combination of two or more.

[0242] The content of the antioxidant in the composition for light diffusion control portion is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 1 part by mass, and even more preferably 0.01 to 0.1 part by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component, which makes it easier to achieve excellent weather resistance.

[0243] Among the above, the composition for the light diffusion control portion preferably contains a photopolymerization initiator. This makes it easier to efficiently form the light diffusion control portion 7 having the desired regular internal structure. As an example of the photopolymerization initiator, the photopolymerization initiator used as the material for the coating layer in the first embodiment can be used.

[0244] When a photopolymerization initiator is used, the content of the photopolymerization initiator in the composition for light diffusion control portion is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 16 parts by mass, particularly preferably 0.8 to 13 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component. This makes it easy to efficiently form light diffusion control portion 7 having a desired regular internal structure.

[0245] (5) Preparation of composition for light diffusion control portion The composition for light diffusion control portion can be prepared by uniformly mixing the above-mentioned high refractive index component, low refractive index component, and ultraviolet absorbing agent, as well as other additives such as a photopolymerization initiator, if desired.

[0246] During the mixing, a uniform composition for controlling light diffusion may be obtained by stirring while heating to a temperature of 40 to 80° C. Furthermore, a dilution solvent may be added and mixed so that the resulting composition for controlling light diffusion has a desired viscosity.

[0247] (6) Regular internal structure As described above, it is preferable that the light diffusion control section 7 has a louver-like regular internal structure having a plurality of plate-like regions 71 with a relatively high refractive index within a region 72 with a relatively low refractive index.

[0248] In the light diffusion control unit 7, similarly to the light diffusion control unit 3' in the first embodiment, it is preferable that the plate-like region 71 is inclined. In this case, the angle of inclination relative to the thickness direction of the light diffusion control unit 7 is preferably 0° to 30°, more preferably 1° to 25°, particularly preferably 2° to 20°, even more preferably 3° to 15°, and of these, preferably 3° to 10°. This makes it easier for the aerial image forming device 10 according to the third embodiment to suppress the occurrence of ghost images or ambient light and to display brighter aerial images.

[0249] The light diffusion control unit 7 may be bent in the middle of the thickness direction, similar to the light diffusion control unit 3′ in the first embodiment, and may be formed by stacking two or more layers of a regular internal structure in which plate-shaped regions 71 are arranged.

[0250] (7) Thickness of Light Diffusion Control Unit The thickness of the light diffusion control unit 7 is preferably 1 to 500 μm, more preferably 10 to 300 μm, particularly preferably 50 to 250 μm, even more preferably 80 to 200 μm, and most preferably 100 to 160 μm. This makes it easier for the aerial image forming device 10 according to the third embodiment to suppress the occurrence of ghost images or ambient light, and to display brighter aerial images.

[0251] (8) Method for Forming the Light Diffusion Control Parts The method for forming the light diffusion control parts 7 is not particularly limited, and they can be formed by a conventionally known method.

[0252] For example, the composition for light diffusion control portion described above is applied to one side of a process sheet to form a coating film, and then one side (particularly the release side) of a release sheet is laminated to the side of the coating film opposite the process sheet. Subsequently, the coating film is irradiated with active energy rays through the process sheet or through the release sheet to cure it, thereby forming the light diffusion control portion 7. In this way, laminating the release sheet on the coating film maintains a gap between the release sheet and the process sheet, suppresses crushing of the coating film, and makes it easier to form a light diffusion control portion 7 having a uniform thickness and a desired regular internal structure.

[0253] Examples of the release sheet include resin films such as polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene vinyl acetate films, ionomer resin films, ethylene-(meth)acrylic acid copolymer films, ethylene-(meth)acrylic acid ester copolymer films, polystyrene films, polycarbonate films, polyimide films, and fluororesin films. Crosslinked films of these may also be used. Furthermore, laminated films of these may also be used. From the perspective of the SDGs, the material constituting the release sheet may be a material with a high biomass content, a recyclable or reusable material, or a recycled or reused material.

[0254] The release surface of the release sheet is preferably subjected to a release treatment. Preferred examples of the release agent used for the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.

[0255] The thickness of the release sheet is not particularly limited, but from the viewpoint of excellent handling and of being able to well protect the light diffusion control portion until use, it is preferably 20 to 200 μm, more preferably 30 to 100 μm.

[0256] The process sheet may be the resin film, crosslinked film, or laminated film thereof used as the release sheet described above. The release sheet described above may also be used as the process sheet.

[0257] The thickness of the process sheet is preferably 20 to 250 μm, more preferably 30 to 200 μm, from the viewpoint of facilitating the formation of the desired light diffusion control portions and of being able to adequately protect the light diffusion control portions until use.

[0258] Examples of the coating method include knife coating, roll coating, bar coating, blade coating, die coating, and gravure coating. The composition for light diffusion control portion may be diluted with a solvent as needed.

[0259] The coating film can be irradiated with active energy rays by a conventionally known method. For example, a linear light source is used as a light source of active energy rays, and the surface of the target is irradiated with band-like (almost linear) light that is random in the width direction (TD direction) and approximately parallel in the machine direction (MD direction). Note that the inclination angle of the plate-like region 71 can also be adjusted by adjusting the irradiation angle of the light.

[0260] The active energy rays refer to electromagnetic waves or charged particle rays that have an energy quantum, and specific examples include ultraviolet rays, electron beams, etc. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle and can easily form a desired regular internal structure.

[0261] When ultraviolet rays are used as the active energy rays, the irradiation conditions are such that the peak irradiance on the coating surface is 0.1 to 200 mW / cm ２ Furthermore, it is preferable that the integrated light amount on the coating surface is 5 to 300 mJ / cm ２Furthermore, the relative moving speed of the light source of the active energy rays with respect to the object to be irradiated is preferably 0.1 to 10 m / min.

[0262] From the viewpoint of completing the curing more reliably, it is also preferable to irradiate the cured product with normal active energy rays (active energy rays that have not been subjected to a process of converting them into parallel light or band-like light, or scattered light) after curing using the band-like light as described above.

[0263] 4. Weather-Resistant Layer The weather-resistant layer 8 in the third embodiment is not limited in material or configuration as long as it contains an ultraviolet absorber. As described above, examples of the weather-resistant layer 8 include at least one of a coating layer containing an ultraviolet absorber, a pressure-sensitive adhesive layer containing an ultraviolet absorber, an adhesive layer containing an ultraviolet absorber, and a substrate containing an ultraviolet absorber. From the perspective of the SDGs, the material constituting the weather-resistant layer 8 may be a material with a high biomass content, a recyclable or reusable material, or a recycled or reused material.

[0264] (1) Coating Layer When the weather-resistant layer 8 in the third embodiment is a coating layer, the coating layer is preferably laminated on the side of the light-transmitting image forming unit 2 opposite the display unit 1, and serves to protect the outermost surface of the laminate including the light-transmitting image forming unit 2, etc. Specific examples of the coating layer include a hard coating layer and a self-repairing layer.

[0265] The coating layer is preferably formed by curing a coating composition containing an active energy ray-curable component, the above-mentioned ultraviolet absorber, and other additives. The ultraviolet absorber used here can be any of those described above.

[0266] (2) Adhesive Layer When the weather-resistant layer 8 in the third embodiment is an adhesive layer, the adhesive layer is preferably used to bond the components constituting the aerial image forming devices 10 e, 10 f, and 10 g together. The adhesive constituting the adhesive layer is not particularly limited, and for example, the adhesives described in the first and second embodiments can be used.

[0267] (3) Adhesive Layer When the weather-resistant layer 8 in the third embodiment is an adhesive layer, it is preferable that the adhesive layer be used to fix the components that make up the aerial image forming devices 10e, 10f, and 10g together.

[0268] The adhesive constituting the adhesive layer is not particularly limited. From the viewpoint of making it easier to view the aerial image, it is preferable that the adhesive be transparent. The material constituting the adhesive layer is not particularly limited, and for example, a material consisting of a thermoplastic resin and a low-molecular-weight thermosetting adhesive component, or a material consisting of a B-stage (semi-cured) thermosetting adhesive component, etc. can be used. Among these, the material constituting the adhesive layer is preferably one containing a thermoplastic resin and a thermosetting adhesive component. Furthermore, the ultraviolet absorber can be one described above.

[0269] (4) Substrate When the weather-resistant layer 8 in the third embodiment is a substrate, the substrate may be, for example, provided on the outermost surface on the viewer side of a laminate composed of the light-transmitting imaging unit 2, etc., and may have the role of protecting the laminate, or may have the role of supporting other components that make up the aerial image forming devices 10e, 10f, and 10g.

[0270] The substrate may be formed from a material containing a base material and an ultraviolet absorber. The base material is not particularly limited, but is preferably a resin, particularly a transparent resin. The ultraviolet absorber may be any of those previously described.

[0271] 5. Other Components The aerial image forming devices 10e, 10f, and 10g according to the third embodiment may include components other than the above-described display unit 1, light diffusion control unit 7, translucent image forming unit 2, and weather-resistant layer 8. In particular, the aerial image forming device 10 according to the third embodiment preferably includes a housing for fixing and accommodating the display unit 1, light diffusion control unit 7, translucent image forming unit 2, and weather-resistant layer 8 in predetermined positions.

[0272] The material, shape, dimensions, etc. of the housing can be appropriately selected depending on the application and purpose. In particular, it is preferable that the housing is made of a light-blocking material, which can prevent unintended leakage of light from the display unit 1 to the outside and can prevent unintended intrusion of external light into the optical path from the display unit 1 to the light diffusion control unit 7, etc.

[0273] 6. Positional Relationship of Each Element In the aerial image forming devices 10e, 10f, and 10g according to the third embodiment, it is preferable to satisfy the condition regarding the "acute angle between the first direction and the second direction," as in the first embodiment.

[0274] Furthermore, when the aerial image forming devices 10e, 10f, and 10g of the third embodiment are equipped with the aforementioned retro-transmitting optical element having a dihedral corner reflector array structure as the light-transmitting imaging unit 2, or a retro-transmitting optical element consisting of two layers stacked together each having multiple reflective surfaces, it is preferable that each element of the aerial image forming devices 10c and 10d be configured so as to simultaneously satisfy "(Condition 1)" and "(Condition 2)," as in the first embodiment.

[0275] 7. Physical Properties of the Aerial Image Forming Device In the aerial image forming devices 10e, 10f, and 10g according to the third embodiment, for a laminate including the light-transmitting imaging unit 2, the light diffusion control unit 7, and the weather-resistant layer 8, the absolute value of the chromaticity b* (initial b*) defined by the CIE 1976 L*a*b* color system relative to a black plate is preferably 1.0 or less, more preferably 0.7 or less, particularly preferably 0.5 or less, and even more preferably 0.3 or less. The lower limit of the absolute value of the chromaticity b* (initial b*) is preferably 0, but may typically be 0.01 or more, or may be 0.1 or more.

[0276] Furthermore, after the laminate is irradiated with ultraviolet light for 1000 hours in an atmosphere of 63±3°C and 50% RH, the absolute value Δb* of the difference between the chromaticity b* defined by the CIE 1976 L*a*b* color system for a black plate and the initial b* is preferably 0.01 to 1.5, more preferably 0.05 to 1.0, and even more preferably 0.1 to 0.6.

[0277] Furthermore, after the laminate is irradiated with ultraviolet light for 2000 hours in an atmosphere of 63±3°C and 50% RH, the absolute value Δb* of the difference between the chromaticity b* defined by the CIE 1976 L*a*b* color system for a black plate and the initial b* is preferably 0.01 to 1.5, more preferably 0.05 to 1.2, particularly preferably 0.08 to 0.9, and further preferably 0.1 to 0.6.

[0278] Furthermore, after the laminate is irradiated with ultraviolet light for 3000 hours in an atmosphere of 63±3°C and 50% RH, the absolute value Δb* of the difference between the chromaticity b* defined by the CIE 1976 L*a*b* color system for a black plate and the initial b* is preferably 0.01 to 1.5, more preferably 0.05 to 1.2, particularly preferably 0.08 to 1.0, further preferably 0.1 to 0.9, and of these, preferably 0.2 to 0.8.

[0279] By satisfying the above conditions, the aerial image forming devices 10e, 10f, and 10g according to the third embodiment are likely to have superior weather resistance. Details of the methods for measuring the chromaticity b* and Δb* are as described in the tests described below.

[0280] 8. Manufacturing Method of Aerial Image Forming Device The manufacturing method of the aerial image forming devices 10e, 10f, and 10g according to the third embodiment is not particularly limited. For example, after preparing the display unit 1, the light diffusion control unit 7, the light-transmitting image forming unit 2, and the weather-resistant layer 8, the display unit 1 is placed in a predetermined position on the housing, and a laminate of the light diffusion control unit 7, the light-transmitting image forming unit 2, and the weather-resistant layer 8 is placed, thereby obtaining the aerial image forming devices 10e, 10f, and 10g.

[0281] 9. Method of Using the Aerial Image Forming Device The aerial image forming devices 10e, 10f, and 10g according to the third embodiment can be used as display devices for displaying any image or video in the air. The specific method of use is not limited, and they can be used in the same way as conventionally known display devices.

[0282] [Laminated Body According to a Third Embodiment] The laminated body according to the third embodiment is a laminated body obtained by omitting the display unit 1 from the aerial image forming devices 10e, 10f, and 10g described above. That is, the laminated body according to the third embodiment includes a translucent imaging unit 2 that forms an image of light incident from one surface at a position on the other surface, and a light diffusion control unit 7 laminated on one surface of the translucent imaging unit 2. The laminated body further includes a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control unit 7 contains an ultraviolet absorber. Details of the composition, structure, and the like of the light diffusion control unit 7, the translucent imaging unit 2, and the weather-resistant layer 8 are as described above.

[0283] The laminate according to the third embodiment can be obtained by preparing the light diffusion control unit 7, the light-transmitting image forming unit 2, and the weather-resistant layer 8 and then laminating them. The laminate according to the third embodiment can also be used to form the aerial image forming devices 10e, 10f, and 10g according to the third embodiment. That is, by placing the display unit 1 at a predetermined position on the laminate according to the third embodiment, the aerial image forming devices 10e, 10f, and 10g according to the third embodiment can be obtained.

[0284] In this specification, when it is stated that "X to Y" (X and Y are any numbers), it means "X or more and Y or less" unless otherwise specified, and also means "preferably greater than X" or "preferably smaller than Y". Furthermore, when it is stated that "X or more" (X is any number), it means "preferably greater than X" unless otherwise specified, and when it is stated that "Y or less" (Y is any number), it also means "preferably smaller than Y" unless otherwise specified.

[0285] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0286] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0287] [Examples According to First Embodiment] [Example 1-1] 100 parts by mass (solids equivalent, the same applies hereinafter) of pentaerythritol tri- and tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "NK Ester A-TMM-3L"), which is a polyfunctional acrylate monomer, 25 parts by mass of dimethylaminoethyl methacrylate (quaternary ammonium salt, manufactured by Kyoeisha Chemical Co., Ltd., product name "Light Ester DQ-100"), which serves as an antistatic agent, and 3 parts by mass of α-hydroxyalkylphenone, which serves as a photopolymerization initiator, were mixed using isopropyl alcohol (IPA) to obtain a coating liquid of an antistatic composition.

[0288] The antistatic composition coating solution obtained above was applied to one side of a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4360", thickness: 125 μm) as a substrate using a wire bar #14. The coating film thus formed was dried by heating at 70°C for 1 minute, and then cured by irradiating with ultraviolet light using a nitrogen-purged compact ultraviolet irradiation device (manufactured by GS Yuasa Corporation) under the following ultraviolet irradiation condition 1 to form a coating layer. This resulted in a coating film in which a 5 μm-thick coating layer was formed on the substrate.

[0289] <Ultraviolet light irradiation condition 1> Light source: high-pressure mercury lamp Lamp power: 2 kW Conveyor speed: 13.0 m / min Illuminance: 300 mW / cm ２ ・Light intensity: 240mJ / cm ２ Nitrogen purge: None

[0290] Example 1-2 Coating solution A was obtained by mixing 42 parts by mass of amorphous silica having an average particle size of 50 nm, 28 parts by mass of pentaerythritol tetraacrylate as a polyfunctional acrylate monomer, and 0.9 parts by mass of α-aminoalkylphenone as a photopolymerization initiator using propylene glycol monomethyl ether (PGM).

[0291] The coating solution A obtained above was applied to one side of a triacetyl cellulose (TAC) film (manufactured by Konica Minolta, Inc., product name "KC8UAW", thickness: 80 μm) as a substrate using a wire bar #14. The coating film thus formed was dried by heating at 70°C for 1 minute, and then cured by irradiating with ultraviolet light using a nitrogen-purged compact ultraviolet irradiation device (manufactured by GS Yuasa Corporation) under the aforementioned ultraviolet irradiation condition 1 to form a coating layer (first layer). This resulted in a coating film in which a 5 μm-thick coating layer (first layer) was formed on the substrate.

[0292] 27 parts by mass of indium tin oxide having an average particle size of 50 nm as an antistatic agent, 7.7 parts by mass of pentaerythritol tri- and tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "NK Ester A-TMM-3L") as a polyfunctional acrylate monomer, and 0.2 parts by mass of α-aminoalkylphenone as a photopolymerization initiator were mixed using isobutyl alcohol (IBA) to obtain coating solution B of an antistatic composition.

[0293] Next, the coating solution B of the antistatic composition obtained above was applied to the surface of the coating film consisting of the substrate and the coating layer (first layer) on the side of the coating layer (first layer) using a wire bar #4. The coating film thus formed was dried by heating at 50°C for 1 minute, and then cured by irradiating with ultraviolet light using a nitrogen-purged compact ultraviolet irradiation device (manufactured by GS Yuasa Corporation) under the ultraviolet irradiation condition 2 below to form a coating layer (second layer). This resulted in a coating film consisting of the substrate, the coating layer (first layer), and a 0.1 µm-thick coating layer (second layer).

[0294] <Ultraviolet light irradiation conditions 2> Light source: high-pressure mercury lamp Lamp power: 2 kW Conveyor speed: 13.0 m / min Illuminance: 300 mW / cm ２・Light intensity: 240mJ / cm ２ Nitrogen purge: Yes (oxygen concentration: 500 ppm or less)

[0295] Furthermore, 10 parts by mass of a photocurable polyfunctional urethane acrylate resin (manufactured by Arakawa Chemical Industries, Ltd., product name "Beamset 575CB"), 36.6 parts of a hollow silica dispersion (manufactured by JGC Catalysts and Chemicals Co., Ltd., product name "Surulia 5320", solid content concentration 20.5%), and 0.2 parts by mass of α-aminoalkylphenone as a polymerization initiator were mixed using a 1:1 mixed liquid of cyclohexane and MIBK to obtain a coating liquid C.

[0296] The coating solution C obtained above was then applied to the surface of the coating film (second layer) comprising the substrate, the coating layer (first layer), and the coating layer (second layer) using a wire bar #4. The coating film thus formed was dried by heating at 90°C for 1 minute, and then cured by irradiating with ultraviolet light under the ultraviolet irradiation condition 2 using a nitrogen-purged compact ultraviolet irradiation device (manufactured by GS Yuasa Corporation) to form the coating layer (third layer). This resulted in a coating film comprising the substrate, the coating layer (first layer), the coating layer (second layer), and a 0.1 µm-thick coating layer (third layer).

[0297] Example 1-3 27 parts by mass of indium tin oxide having an average particle size of 50 nm as an antistatic agent, 7.7 parts by mass of pentaerythritol tetraacrylate (PETA) as a polyfunctional acrylate monomer, and 0.2 parts by mass of α-aminoalkylphenone as a photopolymerization initiator were mixed using a 7:5 mixture of ethanol and IBA to obtain a coating liquid of an antistatic composition.

[0298] The antistatic composition coating solution obtained above was applied to one side of a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4360", thickness: 125 μm) as a substrate using a wire bar #14. The coating film thus formed was dried by heating at 50°C for 1 minute, and then cured by irradiating with ultraviolet light using a nitrogen-purged compact ultraviolet irradiation device (manufactured by GS Yuasa Corporation) under the aforementioned ultraviolet irradiation condition 2 to form a coating layer. This resulted in a coating film in which a 2 μm-thick coating layer was formed on the substrate.

[0299] [Comparative Example 1-1] A surface-coated polyethylene terephthalate film (manufactured by Lintec Corporation, product name "HA149-125G1C") was prepared and used as a coating film according to Comparative Example 1-1. Note that this coating film did not include a layer containing an antistatic agent.

[0300] [Test Example 1-1] (Measurement of Surface Resistivity) For the coating films obtained in the Examples and Comparative Examples, the surface resistance of the coating layer was measured using a resistivity meter (manufactured by Nitto Seiko Analytech Co., Ltd., product name "Hiresta-UX MCP-HT800") in accordance with JIS C2139-3 at an applied voltage of 100 V. The results are shown in Table 1.

[0301] [Test Example 1-2] (Evaluation of Antistatic Properties) The coating layers of the coating films obtained in the Examples and Comparative Examples were rubbed with a flannel cloth for 10 seconds to cause frictional charging. The frictionally charged coating films were then brought close to crushed granular polystyrene foam to evaluate whether the polystyrene foam adhered to the coating film. The results are shown in Table 1.

[0302] Test Example 1-3 (Evaluation of visibility of aerial image) The substrate film side of the coating film produced in the Examples and Comparative Examples was laminated to one side of a retrotransmitting optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200 mm × width 200 mm × thickness 6.3 mm) consisting of two layers with multiple reflective surfaces, which served as a light-transmitting imaging section.

[0303] The resulting laminate of the coating film and the light-transmitting image forming part was placed in a housing with the main surface of the laminate horizontal and the surface facing the light-transmitting image forming part facing downwards. Furthermore, a laptop computer screen was placed in the housing as a display unit, facing the laminate of the coating film and the light-transmitting image forming part.

[0304] When the display unit was installed, the angle between the display surface of the display unit and the main surface of the light-transmitting image forming unit was 45°. The housing was light-shielding so that light emitted from the display unit would not escape to the outside except through the coating film and the light-transmitting image forming unit.

[0305] As a result, an aerial image forming device was obtained in which the coating film, the light-transmitting image forming section, and the display section were arranged inside the housing.

[0306] The surface of the coating film was then rubbed with a flannel cloth for 10 seconds to cause frictional charging, after which pulverized polystyrene foam into granules was brought close to the frictionally charged coating film.

[0307] Thereafter, an image measuring 70 mm in height and 100 mm in width was displayed on the display unit to generate an aerial image, and the visibility of the aerial image was observed visually. The results are shown in Table 1. ◯: No polystyrene foam was attached, and the aerial image was very well visible. ×: Polystyrene foam was attached, making the aerial image difficult to view.

[0308]

[0309] As can be seen from Table 1, the coating films obtained in the examples have excellent antistatic properties, and when used in an aerial image forming device, they enable good visibility of the aerial image.

[0310] [Examples according to the second embodiment] [Production Example 2-1] (Pressure-sensitive adhesive layer A, total light transmittance of 90% or more and less than 100%) 70 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of methyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate were copolymerized by solution polymerization to obtain a (meth)acrylic acid ester polymer. The weight average molecular weight (Mw) of the (meth)acrylic acid ester polymer was measured by the method described below and was found to be 800,000.

[0311] 100 parts by mass of the obtained (meth)acrylic acid ester polymer, 0.2 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed, thoroughly stirred, and diluted with methyl ethyl ketone to obtain a coating solution of a pressure-sensitive adhesive composition.

[0312] The obtained coating solution was applied using a knife coater to the release-treated surface of a heavy-release type heavy-release sheet (thickness: 38 μm) in which one side of a polyethylene terephthalate film had been treated with a silicone-based release agent, and then dried by heating at 90°C for 1 minute in a drying oven to obtain a coating layer.

[0313] Next, a release-treated surface of a light-release type light-release sheet (thickness: 38 μm) made by treating one side of a polyethylene terephthalate film with a silicone-based release agent was attached to the surface of the coating layer opposite to the heavy-release sheet, and then the coating layer was cured for 7 days under conditions of 23° C. and 50% RH, thereby forming the pressure-sensitive adhesive layer A.

[0314] As a result, a pressure-sensitive adhesive sheet was obtained in which the heavy release sheet, the 25 μm thick pressure-sensitive adhesive layer A, and the light release sheet were laminated in this order.

[0315] The total light transmittance (%) of the pressure-sensitive adhesive layer A formed as described above was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997 and ASTM D 1003, and was found to be 90% or more and less than 100%.

[0316] The weight average molecular weight (Mw) is a weight average molecular weight converted to standard polystyrene measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> Measurement device: HLC-8320, manufactured by Tosoh Corporation GPC columns (passed in the following order): TSK gel super H-H, TSK gel super HM-H, TSK gel super H2000, manufactured by Tosoh Corporation Measurement solvent: tetrahydrofuran Measurement temperature: 40°C

[0317] [Production Example 2-2] (Adhesive layer B, total light transmittance 80%) 100 parts by mass of the (meth)acrylic acid ester polymer described in Production Example 1, 0.2 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, 0.30 parts by mass of a carbon black-based black pigment (C1) as a coloring component, and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed, thoroughly stirred, and diluted with methyl ethyl ketone to obtain a coating solution of a pressure-sensitive adhesive composition.

[0318] A PSA sheet comprising a heavy release sheet, a 30 μm thick PSA layer B, and a light release sheet laminated in that order was obtained in the same manner as in Production Example 2-1, except that the coating solution of the PSA composition was used.

[0319] The carbon black pigment (C1) used as the coloring component was diluted 10,000 times with ethyl acetate, and the haze value (%) was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000", optical path length 10 mm) in accordance with JIS K7136:2000. From the measured values, the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, the average haze which is the average value of the haze values ​​at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, and the standard deviation of the haze values ​​at each wavelength in 5 nm intervals in the wavelength range from 380 nm to 780 nm were calculated. The respective results are shown in Table 1.

[0320] The total light transmittance (%) of the formed pressure-sensitive adhesive layer B was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997 and ASTM D 1003, and was found to be 80%.

[0321] [Production Example 2-3] (Adhesive Layer C, Total Light Transmittance 50%) A coating solution of an adhesive composition was obtained in the same manner as in Production Example 2-2, except that the blending amount of the coloring component was 0.94 parts by mass.

[0322] A PSA sheet comprising a heavy release sheet, a 30 μm thick PSA layer C, and a light release sheet laminated in that order was obtained in the same manner as in Production Example 2-1, except that the coating solution of the PSA composition was used.

[0323] The total light transmittance (%) of the pressure-sensitive adhesive layer C thus formed was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997 and ASTM D 1003, and was found to be 50%.

[0324] [Production Example 2-4] (Adhesive Layer D, Total Light Transmittance 30%) A coating solution of an adhesive composition was obtained in the same manner as in Production Example 2-2, except that the blending amount of the coloring component was 1.63 parts by mass.

[0325] A PSA sheet comprising a heavy release sheet, a 30 μm thick PSA layer D, and a light release sheet laminated in that order was obtained in the same manner as in Production Example 2-1, except that the coating solution of the PSA composition was used.

[0326] The total light transmittance (%) of the formed pressure-sensitive adhesive layer D was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997 and ASTM D 1003, and was found to be 30%.

[0327] [Manufacturing Example 2-5] (Light diffusion control portion) 1. Preparation of composition for light diffusion control portion As a low refractive index component, 40 parts by mass (solid content equivalent value; the same hereinafter) of polyether urethane methacrylate having a weight average molecular weight of 9,900 obtained by reacting polypropylene glycol, isophorone diisocyanate, and 2-hydroxyethyl methacrylate, was added with 60 parts by mass of o-phenylphenoxyethoxyethyl acrylate having a molecular weight of 268 as a high refractive index component, and 8 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator, and then the mixture was heated and mixed at 80 ° C. to obtain a composition for light diffusion control portion.

[0328] 2. Formation of Light Diffusion Control Part The obtained composition for light diffusion control part was applied to a process sheet A (thickness: 50 μm) made of a polyethylene terephthalate film as a process sheet to form a coating film. Thereby, a laminate consisting of the coating film and the process sheet A was obtained.

[0329] Next, the obtained laminate was placed on a conveyor. At this time, the surface of the coating film on the laminate was facing upward, and the longitudinal direction of the process sheet A was parallel to the flow direction of the conveyor. Then, an ultraviolet irradiation device (manufactured by iGraphics, product name "ECS-4011GX") equipped with a linear high-pressure mercury lamp and a cold mirror for focusing was installed relative to the conveyor on which the laminate was placed. This device can irradiate a single point of interest with scattered ultraviolet light in a band shape (almost linear). Note that when installing the device, the ultraviolet irradiation device was installed so that the longitudinal direction of the high-pressure mercury lamp and the flow direction of the conveyor were perpendicular to each other.

[0330] Furthermore, when viewed from the longitudinal direction of the high-pressure mercury lamp, the irradiation angle of the ultraviolet light irradiated from the high-pressure mercury lamp to the laminate was set to -5° with respect to the normal to the laminate surface. Note that the irradiation angle here refers to the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a plus sign, when the ultraviolet light is irradiated toward the downstream side of the conveyor flow, with respect to the position directly below the high-pressure mercury lamp on the laminate, and the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a minus sign, when the ultraviolet light is irradiated toward the upstream side of the conveyor flow.

[0331] Thereafter, the conveyor was operated to move the laminate at a speed of 1.0 m / min, while applying a peak irradiance of 2.5 mW / cm2 to the coating surface. ２ , cumulative light intensity 40.0 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light under the conditions (this curing is sometimes referred to as "primary curing" for convenience).

[0332] Next, a process sheet B (thickness: 38 μm) made of a polyethylene terephthalate film was laminated on the surface of the laminate facing the coating film, to obtain a laminate consisting of the process sheet A, the coating film, and the process sheet B laminated in this order. Next, while moving at a speed of 1.0 m / min, a peak irradiance of 190 mW / cm was applied to the coating film via the process sheet B. ２ , cumulative light intensity 180 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light (scattered light) under the conditions (this curing is sometimes referred to as "secondary curing" for convenience). The peak irradiance and integrated light quantity mentioned above were measured by placing a UV meter (manufactured by Eye Graphics, product name "Eye Ultraviolet Integrated Illuminance Meter UVPF-A1") equipped with a light receiver at the position of the coating film.

[0333] The coating film was sufficiently cured by the above primary and secondary curing processes to form the light diffusion control portion, thereby obtaining a laminate in which the process sheet A, the light diffusion control portion having a thickness of 140 μm, and the process sheet B were laminated in this order.

[0334] Furthermore, when the cross section of the formed light diffusion control section was observed using a microscope, it was confirmed that a louver structure was formed inside the light diffusion control section, in which a plurality of plate-like regions 61 were arranged in parallel at predetermined intervals, as shown in Fig. 6. The acute angle formed between the main surface of the louver structure and the normal to the light diffusion control section was 3.3°.

[0335] Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-2 Using the pressure-sensitive adhesive sheets produced in Production Examples 2-1 to 2-4 as appropriate, laminates having the layer configurations shown in Table 2 were produced. That is, the release sheets were appropriately peeled off from the produced pressure-sensitive adhesive sheets, and the respective members were bonded together using the pressure-sensitive adhesive layers to form the laminates shown in Table 2.

[0336] Details of the abbreviations and the like in Table 2 are as follows: AR: anti-reflection film (manufactured by NOF Corporation, product name "Airlike 1202UV-50", thickness: 75 μm) Light-transmitting imaging part: retrotransmitting optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200 mm × width 200 mm × thickness 6.3 mm) PET38: polyethylene terephthalate film with a thickness of 38 μm Light diffusion control part: light diffusion control part manufactured as in the above-mentioned Manufacturing Example 5 PET50: polyethylene terephthalate film with a thickness of 50 μm PET25: polyethylene terephthalate film with a thickness of 25 μm

[0337] Test Example 2-1 (Measurement of Optical Properties) The total light transmittance (%) and haze value (%) of the laminates produced in the Examples and Comparative Examples were measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997 and ASTM D 1003. The results are shown in Table 3.

[0338] [Test Example 2-2] (Measurement of Color Difference) For the laminates obtained in the examples and comparative examples, a spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE6000") was used to measure the lightness L*, chromaticity a*, and chromaticity b* defined by the CIE1976 L*a*b* color system for the reflected light of incident light from the viewer side of the laminate. The results are shown in Table 3.

[0339] Furthermore, the lightness L*, chromaticity a*, and chromaticity b* of the surface of a black plate (manufactured by Mitsubishi Chemical Corporation, product name "Acrylite L502 Black") as a housing sample were measured in the same manner as above. As a result, the lightness L*, chromaticity a*, and chromaticity b* of the black plate were 3.3, 0.1, and 0.1, respectively.

[0340] Then, the color difference ΔE* defined by the CIE 1976 L*a*b* color system relative to a black plate was calculated for the laminates obtained in the examples and comparative examples based on the following formula (1). The results are shown in Table 3.

[0341]

[0342] In formula (1), L*2, a*2, and b*2 represent the lightness L*, chromaticity a*, and chromaticity b* of the laminate, respectively, and L*3, a*3, and b*3 represent the lightness L*, chromaticity a*, and chromaticity b* of the black board, respectively.

[0343] Test Example 2-3 (Evaluation of Visibility of Aerial Images) The laminates obtained in the Examples and Comparative Examples were placed in a specified housing so that the main surface of the laminate was horizontal and the surface facing the viewer was facing upward. Furthermore, a laptop computer screen was placed in the housing as a display unit, facing the laminate. This resulted in an aerial image forming device.

[0344] When the display unit was installed, the angle between the display surface of the display unit and the main surface of the light-transmitting imaging unit was 45°. The housing was light-shielding so that light emitted from the display unit would not escape to the outside from anywhere other than the laminate.

[0345] An image measuring 70 mm in height and 100 mm in width was then displayed on the display unit to generate an aerial image, and the visibility of the aerial image was observed visually. The visibility of the aerial image was evaluated based on the following criteria. The results are shown in Table 32-. ⊚: The aerial image was very brightly visible. ◯: The aerial image was brightly visible. ×: The aerial image was only dimly visible.

[0346] [Test Example 2-4] (Evaluation of Appearance Harmony) For the aerial image forming device produced in Test Example 2-3, the appearance of the exposed surface of the laminate from the housing and the area surrounding the exposed surface of the housing were visually inspected. Then, the appearance harmony was evaluated based on the following criteria. The results are shown in Table 2. ⊚: Both areas blended very well. ◯: Both areas blended to some extent. ×: Both areas clearly did not blend well.

[0347]

[0348]

[0349] As can be seen from Table 3, the aerial imaging devices obtained in the examples provided good visibility of the aerial image and had excellent appearance harmony. Furthermore, a comparison between the examples also revealed that appearance harmony tends to be better when the colored layer is located closer to the viewer than the light-transmitting imaging unit. Furthermore, Example 2-1 had a higher total light transmittance than Examples 2-2 and 2-3, and the visibility of the aerial image was better. Furthermore, Example 2-7 had a colored layer on the display unit side compared to Example 2-1, which reduced ΔE* and lowered total light transmittance, resulting in poorer visibility, but good appearance harmony.

[0350] [Examples according to the third embodiment] [Example 3-1] 1. Preparation of a composition for a light diffusion control portion 40 parts by mass (solid content equivalent value; the same applies hereinafter) of polyether urethane methacrylate having a weight average molecular weight of 9,900 obtained by reacting polypropylene glycol, isophorone diisocyanate, and 2-hydroxyethyl methacrylate as a low refractive index component, 60 parts by mass of o-phenylphenoxyethoxyethyl acrylate having a molecular weight of 268 as a high refractive index component, and 8.0 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator, 0.05 parts by mass of an acrylic leveling agent (manufactured by BYK Japan, product name "BYK-361N") as the leveling agent, 0.08 parts by mass of a benzotriazole-based ultraviolet absorber (manufactured by BASF Japan, product name "Tinuvin 384-2") as the ultraviolet absorber, and 0.5 parts by mass of a hindered amine-based light stabilizer (manufactured by BASF Japan, product name "Tinuvin 292") as the light stabilizer were added, and then the mixture was heated and mixed at 80°C to obtain a composition for light diffusion control portion.

[0351] The weight average molecular weight (Mw) is a weight average molecular weight calculated as standard polystyrene, measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> Measurement device: HLC-8320, manufactured by Tosoh Corporation GPC columns (passed in the following order): TSK gel super H-H, TSK gel super HM-H, TSK gel super H2000, manufactured by Tosoh Corporation Measurement solvent: tetrahydrofuran Measurement temperature: 40°C

[0352] 2. Formation of Light Diffusion Control Part The obtained composition for light diffusion control part was applied to a polyethylene terephthalate film sheet A (manufactured by Lintec Corporation, product name "SP-PET381130", thickness: 50 μm) as a processing sheet to form a coating film. This resulted in a laminate consisting of the coating film and the processing sheet.

[0353] Next, the obtained laminate was placed on a conveyor. At this time, the surface of the coating film of the laminate was facing upward, and the longitudinal direction of the process sheet was parallel to the flow direction of the conveyor. Then, an ultraviolet irradiation device (manufactured by iGraphics, product name "ECS-4011GX") equipped with a linear high-pressure mercury lamp and a cold mirror for focusing was installed in front of the conveyor on which the laminate was placed. This device can irradiate a single point of interest with scattered ultraviolet light in a band shape (almost linear). Note that when installing the device, the ultraviolet irradiation device was installed so that the longitudinal direction of the high-pressure mercury lamp and the flow direction of the conveyor were perpendicular to each other.

[0354] Furthermore, when viewed from the longitudinal direction of the high-pressure mercury lamp, the irradiation angle of the ultraviolet light irradiated from the high-pressure mercury lamp to the laminate was set to -5° with respect to the normal to the laminate surface. Note that the irradiation angle here refers to the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a plus sign, when the ultraviolet light is irradiated toward the downstream side of the conveyor flow, with respect to the position directly below the high-pressure mercury lamp on the laminate, and the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a minus sign, when the ultraviolet light is irradiated toward the upstream side of the conveyor flow.

[0355] Thereafter, the conveyor was operated to move the laminate at a speed of 1.0 m / min, while applying a peak irradiance of 2.5 mW / cm2 to the coating surface. ２ , cumulative light intensity 40.0 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light under the conditions (this curing is sometimes referred to as "primary curing" for convenience).

[0356] Next, a process sheet B (thickness: 38 μm) made of a polyethylene terephthalate film was laminated on the surface of the laminate facing the coating film, to obtain a laminate consisting of the process sheet (sheet A), the coating film, and process sheet B laminated in this order. Next, while moving at a speed of 1.0 m / min, a peak irradiance of 190 mW / cm was applied to the coating film via the process sheet B. ２ , cumulative light intensity 180 mJ / cm ２ The coating film in the laminate was cured by irradiating it with ultraviolet light (scattered light) under the conditions (this curing is sometimes referred to as "secondary curing" for convenience). The peak irradiance and integrated light quantity mentioned above were measured by placing a UV meter (manufactured by Eye Graphics, product name "Eye Ultraviolet Integrated Illuminance Meter UVPF-A1") equipped with a light receiver at the position of the coating film.

[0357] The coating film was sufficiently cured by the above primary and secondary curing processes to form the light diffusion control portion, thereby obtaining a laminate in which the process sheet A, the light diffusion control portion having a thickness of 165 μm, and the process sheet B were laminated in this order.

[0358] Furthermore, when the cross section of the formed light diffusion control section was observed using a microscope, it was confirmed that a louver structure was formed inside the light diffusion control section, in which a plurality of plate-like regions 71 were arranged in parallel at predetermined intervals, as shown in Fig. 10. The acute angle formed between the main surface of the louver structure and the normal to the light diffusion control section was 5°.

[0359] 3. Formation of Pressure-Sensitive Adhesive Layer 67.2 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of methyl methacrylate, 8 parts by mass of methacrylic acid, 18 parts by mass of vinyl acetate, 0.4 parts by mass of acrylic acid, and 1.4 parts by mass of 4-hydroxybutyl acrylate were copolymerized by solution polymerization to obtain a (meth)acrylic acid ester polymer. The weight average molecular weight (Mw) of the (meth)acrylic acid ester polymer was measured by the method described above and was found to be 820,000.

[0360] 100 parts by mass of the obtained (meth)acrylic acid ester polymer, 0.5 parts by mass of an isocyanate-based crosslinking agent (manufactured by Tosoh Corporation, product name "Coronate HX") as a crosslinking agent, and 7.7 parts by mass of a triazine-based ultraviolet absorber (manufactured by BASF Japan, product name "Tinuvin 477") as an ultraviolet absorber were mixed, thoroughly stirred, and diluted with ethyl acetate to obtain a coating solution of a pressure-sensitive adhesive composition.

[0361] The obtained coating solution was applied using a knife coater to the release-treated surface of a heavy-release type heavy-release sheet (thickness: 38 μm) in which one side of a polyethylene terephthalate film had been treated with a silicone-based release agent, and then dried by heating at 90°C for 1 minute in a drying oven to obtain a coating layer.

[0362] Next, a release-treated surface of a light-release type light-release sheet (thickness: 38 μm) made by treating one side of a polyethylene terephthalate film with a silicone-based release agent was attached to the surface of the coating layer opposite to the heavy-release sheet, and then the coating layer was cured for 7 days under conditions of 23° C. and 50% RH to form a pressure-sensitive adhesive layer.

[0363] As a result, a pressure-sensitive adhesive sheet was obtained in which a heavy release sheet, a 13 μm thick pressure-sensitive adhesive layer, and a light release sheet were laminated in this order.

[0364] 4. Fabrication of Laminate A laminate having the layer structure shown in Fig. 12 was fabricated using the light diffusion control part fabricated in step 2, the adhesive sheet fabricated in step 3, and other members. That is, the release sheet was appropriately peeled off from the fabricated adhesive sheet, and the respective members were bonded together using the adhesive layer to form the laminate shown in Fig. 12.

[0365] 12 , etc. are as follows: AR: anti-reflection film (manufactured by NOF Corporation, product name "AIRLIKE 1202UV-50", thickness: 75 μm) Adhesive layer: adhesive layer obtained by removing the release sheet from the adhesive sheet produced in step 3 Light-transmitting imaging part: retrotransmitting optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200 mm × width 200 mm × thickness 6.3 mm) PET38: polyethylene terephthalate film with a thickness of 38 μm Light diffusion control part: light diffusion control part produced in step 2 PET50: polyethylene terephthalate film with a thickness of 50 μm HC-PET: hard coat film (manufactured by Lintec Corporation, product name "OPTERIA H137-75", thickness: 78 μm)

[0366] Examples 3-2 to 3-6 and Comparative Example 3-1 Except for changing the composition for light diffusion controlling portion as shown in Table 4, a laminate shown in FIG. 12 was formed in the same manner as in Example 3-1.

[0367] The polyfunctional monomer used in Example 3-2 was dipentaerythritol hexaacrylate (DPHA). The "ADK STAB LA-81" used as the light stabilizer in Example 3-3 and elsewhere is a hindered amine-based light stabilizer (manufactured by ADEKA Corporation, product name "ADK STAB LA-81"). The antioxidant used in Example 3-2 and elsewhere was octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (manufactured by ADEKA Corporation, product name "ADK STAB AO-50").

[0368] [Test Example 3-1] (Measurement of Δb*) For the laminates obtained in the examples and comparative examples, the chromaticity b* defined by the CIE 1976 L*a*b* color system was measured using a spectroscopic haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000"), which was designated as "initial chromaticity b*."

[0369] In addition, laminates according to the separately prepared examples and comparative examples were irradiated with ultraviolet light for 3000 hours using a Sunshine Weather Meter (SWOM) (manufactured by Suga Test Instruments Co., Ltd., product name "S80") in an atmosphere of 63±3°C (black panel temperature) and 50% RH in accordance with JIS A1439:2016. Then, chromaticity b* was measured in the same manner as above at 1000 hours, 2000 hours, and 3000 hours. For each of the three measured chromaticity b* values, the initial chromaticity b* value was subtracted to obtain Δb*. The results are shown in Table 4.

[0370] Test Example 3-2 (Evaluation of Aerial Image Visibility) For the laminates obtained in the Examples and Comparative Examples, similar to Test Example 3-1, laminates were prepared by irradiating ultraviolet light for 3,000 hours using a Sunshine Weather Meter (SWOM) (manufactured by Suga Test Instruments Co., Ltd., product name "S80") in an atmosphere of 63±3°C (black panel temperature) and 50% RH in accordance with JIS A1439:2016. The laminate was placed in a specified housing so that the main surface of the laminate was horizontal and the upper surface of Figure 12 faced upward. Furthermore, as a display unit, a laptop computer screen was placed in the housing so that it faced the laminate. This resulted in an aerial image forming device.

[0371] When the display unit was installed, the angle between the display surface of the display unit and the main surface of the light-transmitting imaging unit was 45°. The housing was light-shielding so that light emitted from the display unit would not escape to the outside from anywhere other than the laminate.

[0372] An image measuring 70 mm in height and 100 mm in width was then displayed on the display section to generate an aerial image, and the visibility of the aerial image was visually observed. The visibility of the aerial image was evaluated based on the following criteria. The results are shown in Table 4. Note that for the laminates obtained in the Examples and Comparative Examples, the laminates before irradiation with ultraviolet light were all rated as ⊚. ⊚: No yellowish tint was perceived in the aerial image. ◯: A slight yellowish tint was perceived in the aerial image, but this was at a level that was not problematic in practical use. ×: A clear yellowish tint was perceived in the aerial image.

[0373]

[0374] As can be seen from Table 4, the aerial imaging device obtained in the example did not produce a yellowish tint in the aerial image even after the durability test, and the image was clearly visible.

[0375] The aerial image forming device of the present invention can be suitably used as a display or the like that displays an aerial image.

[0376] 10a, 10b, 10c, 10d, 10e, 10f, 10g... Aerial image forming device 1... Display unit 2... Light-transmitting image forming unit 3... Antistatic layer 3', 6', 7... Light diffusion control unit 31, 61, 71... Plate-shaped region 32, 62, 72... Region with relatively low refractive index 4... Aerial image observation surface 5... Observation point 6... Colored layer 8... Weather-resistant layer

Claims

1. An aerial image forming device comprising: a display unit having a display surface and emitting light from said display surface; a light-transmitting imaging unit arranged on the display surface side of said display unit, transmitting said light and forming an image at a position on the side opposite to said display unit; and a functional layer laminated on the display unit side of said light-transmitting imaging unit or on the side opposite to said display unit of said light-transmitting imaging unit, wherein said functional layer is any one of an antistatic layer containing an antistatic agent, a colored layer containing a coloring component, and a light diffusion control unit, and when said functional layer is said colored layer, a laminate of said light-transmitting imaging unit and said colored layer is measured by a CIE 1976L standard against a black plate. ＊ a ＊ b ＊ Color difference ΔE defined by the color system ＊ is 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less; when the functional layer is the light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index; and the aerial image forming device further comprises a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control section contains an ultraviolet absorber.

2. The aerial image forming device according to claim 1, wherein the functional layer is the antistatic layer, and the antistatic layer is at least one of a coating layer containing the antistatic agent, an adhesive layer containing the antistatic agent, a substrate containing the antistatic agent, and a light diffusion control section containing the antistatic agent, and the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

3. An aerial image forming device as described in claim 1, characterized in that the functional layer is the antistatic layer, and the display unit is arranged relative to the translucent imaging unit and the antistatic layer so that the display surface and one side of the translucent imaging unit are non-parallel.

4. The aerial image forming device described in claim 2, characterized in that the functional layer is the antistatic layer, the antistatic layer is the light diffusion control section, and when a direction perpendicular to the longitudinal direction of the plate-like region and existing in a plane of the light diffusion control section opposite the translucent image forming section is defined as a first direction, each of the plate-like regions is inclined toward the first direction within the light diffusion control section.

5. The aerial image forming device according to claim 1, wherein the functional layer is the colored layer, and the colored layer is an adhesive layer containing the coloring component.

6. The aerial image forming device according to claim 1, characterized in that the functional layer is the colored layer, and the aerial image forming device comprises a light diffusion control section laminated on the side of the translucent imaging section opposite the display section or on the side of the translucent imaging section facing the display section, and the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

7. The aerial image forming device according to claim 6, characterized in that the light diffusion control section contains a coloring component, and the aerial image forming device comprises the light diffusion control section as the coloring layer.

8. The aerial image forming device according to claim 1, characterized in that the functional layer is the colored layer, and the display unit is positioned relative to the translucent imaging unit so that the display surface and one side of the translucent imaging unit are non-parallel.

9. The aerial image forming device described in claim 6, characterized in that, when a direction perpendicular to the longitudinal direction of the plate-like region and existing in a plane opposite the light-transmitting imaging section in the light diffusion control section is defined as a first direction, each of the plate-like regions is inclined toward the first direction within the light diffusion control section.

10. An aerial image forming device as described in claim 1, characterized in that the functional layer is the light diffusion control unit, and the weather-resistant layer is provided on the surface of the translucent imaging unit opposite the light diffusion control unit, the surface of the light diffusion control unit opposite the translucent imaging unit, and at least one position between the translucent imaging unit and the light diffusion control unit.

11. The aerial image forming device described in claim 1, characterized in that the functional layer is the light diffusion control section, and the weather-resistant layer is at least one of a coating layer containing the ultraviolet absorber, a pressure-sensitive adhesive layer containing the ultraviolet absorber, an adhesive layer containing the ultraviolet absorber, and a substrate containing the ultraviolet absorber.

12. The aerial image forming device described in claim 1, characterized in that the functional layer is the light diffusion control unit, and the display unit is positioned relative to the light diffusion control unit and the light-transmitting image forming unit so that the display surface and the surface of the light diffusion control unit opposite the light-transmitting image forming unit are non-parallel.

13. The aerial image forming device of claim 1, characterized in that the functional layer is the light diffusion control section, and when a direction perpendicular to the longitudinal direction of the plate-like region and existing in a plane of the light diffusion control section opposite the light-transmitting image forming section is defined as a first direction, each of the plate-like regions is inclined toward the first direction within the light diffusion control section.

14. The aerial image forming device according to claim 1, wherein the light-transmitting imaging unit is provided with a retrotransmitting optical element that retrotransmits incident light.

15. The aerial image forming device described in claim 14, characterized in that the retrotransmissive optical element is formed by stacking two layers each having a plurality of reflective surfaces, and in each of the two layers, the plurality of reflective surfaces are arranged perpendicular to one side of the retrotransmissive optical element and at a predetermined distance from each other, and the two layers are stacked so that the reflective surface in one layer is perpendicular to the reflective surface in the other layer.

16. A laminate comprising a light-transmitting imaging section that forms an image at a position on the other surface side of the light-transmitting imaging section, and a functional layer laminated on one surface side of the light-transmitting imaging section, wherein the functional layer is any one of an antistatic layer containing an antistatic agent, a colored layer containing a coloring component, and a light diffusion control section, and when the functional layer is the colored layer, the laminate of the light-transmitting imaging section and the colored layer is measured using a CIE 1976L standard against a black plate. ＊ a ＊ b ＊ Color difference ΔE defined by the color system ＊ is 20 or less, and the total light transmittance of the laminate is 10% or more and 100% or less, and when the functional layer is the light diffusion control section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions having a relatively high refractive index within a region having a relatively low refractive index, and the laminate further comprises a weather-resistant layer containing an ultraviolet absorber, or the light diffusion control section contains an ultraviolet absorber.

17. The laminate according to claim 16, wherein the functional layer is the antistatic layer, and the antistatic layer is at least one of a coating layer containing the antistatic agent, an adhesive layer containing the antistatic agent, a substrate containing the antistatic agent, and a light diffusion control portion containing the antistatic agent, and the light diffusion control portion diffuses or transmits light incident into the light diffusion control portion depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

18. The laminate according to claim 16, wherein the functional layer is the colored layer, and the colored layer is an adhesive layer containing the coloring component.

19. The laminate according to claim 16, characterized in that the functional layer is the colored layer, the laminate comprises a light diffusion control section laminated on either side of the light-transmitting imaging section, the light diffusion control section diffuses or transmits light incident into the light diffusion control section depending on the angle of incidence, and has a louver-like regular internal structure with a plurality of plate-like regions with a relatively high refractive index within a region with a relatively low refractive index.

20. The laminate according to claim 19, wherein the functional layer is the colored layer, the light diffusion control portion contains a coloring component, and the laminate comprises the light diffusion control portion as the colored layer.

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