Aerial imaging device and laminate

Abstract

An aerial imaging device (10) is provided with: a display unit (1) that has a display surface and emits light from the display surface; a light-transmitting image forming unit (2) that is disposed on the display surface side of the display unit (1), transmits the light, and forms an image at a position on the surface side opposite the display unit (1); and a light diffusion control unit (3) which is laminated on the surface side of the translucent image forming unit (2) opposite to the display unit (1), and which diffuses or transmits light incident into the light diffusion control unit (3) in accordance with the angle of incidence thereof, and which has a regular internal structure in the shape of a louver. The shutter-like regular internal structure is provided with a plurality of plate-like regions having a relatively high refractive index in a region having a relatively low refractive index. The aerial imaging device (10) can restrain the influence of external light, and aerial images can be well viewed.

Description

Technical Field

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

[0002] Aerial images are formed by reflecting and refracting light emitted from a light source using optical elements, thus creating an image at any location in space. Since no screen or monitor is placed at the location where the aerial image is displayed, the observer experiences an incredible sensation. Therefore, in recent years, aerial images have been fully utilized in various applications, such as virtual reality.

[0003] For example, Patent Document 1 discloses an aerial imaging device having at least a display section and a light-transmitting imaging section, wherein the image (real image) displayed on the display section is displayed as an aerial image mainly through the function of the light-transmitting imaging section.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-060752 Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] When an aerial imaging device is activated, sometimes ambient light caused by an external light source can be seen while viewing the aerial image. For example, if the aerial imaging device is placed under a fluorescent light, the viewer will see ambient light corresponding to that fluorescent light, thus obstructing the view of the aerial image.

[0009] Here, the incoming light is not simply surface reflection from the surface of the translucent imaging element, but rather light that has penetrated into the translucent imaging element and returned to the observer's side. Due to the diffraction effect, it is accompanied by color cracking, thus causing a significant decrease in visibility compared to background reflection from a typical external light source.

[0010] Since aerial imaging devices are also envisioned for use in places like convenience stores where there are many external light sources, they are required to suppress the effects of the aforementioned external light.

[0011] The present invention was made in view of the above-mentioned actual situation, and its object is to provide an aerial imaging device that can suppress the influence of external light and can view aerial images well, and a stack for forming the aerial imaging device.

[0012] (II) Technical Solution

[0013] To achieve the above objectives, firstly, the present invention provides an aerial imaging device, characterized in that it comprises: 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 and transmitting the light to form an image at a position opposite to the display unit; and a light diffusion control unit stacked on the light-transmitting imaging unit at the opposite side of the display unit, wherein the light diffusion control unit diffuses or transmits light incident upon the light diffusion control unit according to its incident angle, and the light diffusion control unit has a regular internal structure in the shape of louvers, wherein the regular internal structure in the shape of louvers has a plurality of plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices (Invention 1).

[0014] In the above invention (Invention 1), it is preferable that the display unit is arranged such that the display surface is not parallel to the surface of the light-transmitting imaging unit that is opposite to the light diffusion control unit (Invention 2).

[0015] In the above invention (Invention 2), it is preferable that: when the first direction is defined as a direction perpendicular to the long side direction of the plate-shaped region and existing in the plane of the light-transmitting imaging portion side of the light diffusion control portion, and the second direction is defined as a plane parallel to the two surfaces perpendicular to the display surface and one surface of the light-transmitting imaging portion and existing in the plane of the light diffusion control portion side of the light-transmitting imaging portion, the acute angle formed by the first direction and the second direction is 0° or more and 90° or less (Invention 3).

[0016] In the above inventions (Inventions 1 to 3), it is preferable that, when the direction perpendicular to the long side direction of the plate-shaped region and existing in the plane of the light-transmitting imaging portion side of the light diffusion control portion is set as the first direction, each of the plate-shaped regions is inclined in the first direction within the light diffusion control portion (Invention 4).

[0017] In the above invention (Invention 4), it is preferable that the tilt angle of the plate-shaped region is 0° or more and 30° or less with respect to the thickness direction of the light diffusion control part (Invention 5).

[0018] In the above inventions (Inventions 1-5), preferably: the light diffusion control unit is a film laminate or a single film, the film laminate is formed by laminating at least two films with regular internal structures in the shape of louvers, the regular internal structures in the shape of louvers having multiple plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices, and the single film is formed by laminating at least two segments of regular internal structures in the shape of louvers having multiple plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices (Invention 6).

[0019] In the above inventions (Inventions 1-5), preferably: the aerial imaging device includes a second light diffusion control unit, which is disposed on the display surface side of the light-transmitting imaging unit. The second light diffusion control unit diffuses or transmits light incident into the second light diffusion control unit according to its incident angle. The second light diffusion control unit has a regular internal structure in the shape of louvers. The regular internal structure in the shape of louvers has a plurality of plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices (Invention 7).

[0020] In the above inventions (Inventions 1 to 7), it is preferable that the light-transmitting imaging unit has a retrotransmission optical element that causes incident light to be transmitted in reverse (Invention 8).

[0021] In the above invention (Invention 8), it is preferred that the retrotransmission optical element is an element formed by stacking two layers having multiple reflective surfaces, wherein in each of the two layers, the multiple reflective surfaces are perpendicular to one surface of the retrotransmission optical element and arranged at a predetermined interval from each other, and the two layers are stacked in such a way that the reflective surface of one layer is orthogonal to the reflective surface of the other layer (Invention 9).

[0022] Second, the present invention provides a laminate comprising: a light-transmitting imaging section that images light incident from one side at a position on the other side; and a light diffusion control section laminated on one side of the light-transmitting imaging section, wherein the light diffusion control section causes light incident into the light diffusion control section to diffuse or transmit according to its incident angle, and the light diffusion control section has a regular internal structure in the shape of louvers, wherein the regular internal structure in the shape of louvers has a plurality of plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices (Invention 10).

[0023] In the above invention (Invention 10), preferably: the light diffusion control unit is a film laminate or a single film, the film laminate is formed by laminating at least two films with regular internal structures in the shape of louvers, the regular internal structures in the shape of louvers having multiple plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices, and the single film is formed by laminating at least two segments of regular internal structures in the shape of louvers having multiple plate-shaped regions with relatively high refractive indices in regions with relatively low refractive indices (Invention 11).

[0024] In the above invention (Invention 10), preferably: the laminate includes a second light diffusion control section disposed on the side opposite to the light diffusion control section of the light-transmitting imaging section, the second light diffusion control section causes light incident into the second light diffusion control section to diffuse or transmit according to its incident angle, the second light diffusion control section has a regular internal structure in the shape of louvers, and the regular internal structure in the shape of louvers has a plurality of plate-shaped regions with relatively high refractive index in the region with relatively low refractive index (Invention 12).

[0025] (III) Beneficial Effects

[0026] The aerial imaging device of the present invention can suppress the influence of external light and can clearly view aerial images. Furthermore, the above-described aerial imaging device can be formed using the laminated body according to the present invention. Attached Figure Description

[0027] Figure 1 A cross-sectional view illustrating an example of an aerial imaging apparatus according to one embodiment of the present invention.

[0028] Figure 2 A perspective view illustrating the internal structure of the light diffusion control unit.

[0029] Figure 3 A graph showing the observation results of Experiment Example 1.

[0030] Figure 4 A cross-sectional view of a light diffusion control unit in an aerial imaging apparatus according to another embodiment of the present invention is shown for illustrative purposes.

[0031] Figure 5 A cross-sectional view of an aerial imaging apparatus according to another embodiment of the present invention is shown for illustrative purposes. Detailed Implementation

[0032] The following describes the embodiments of the present invention.

[0033] [Aerial Imaging Device]

[0034] Figure 1 A cross-sectional view illustrating an example of the aerial imaging apparatus of this embodiment is shown below. Figure 1 As shown, the aerial imaging device 10 of this embodiment includes: 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 transmitting the light to form an image at a position opposite to the display unit 1; and a light diffusion control unit 3 stacked on the light-transmitting imaging unit 2 on the side opposite to the display unit 1.

[0035] In this embodiment, the light diffusion control unit 3 diffuses or transmits light incident on it according to its incident angle. Figure 2 A perspective view illustrating the internal structure of the light diffusion control unit 3 is shown. Figure 2As shown, the light diffusion control unit 3 has a regular internal structure resembling louvers, with multiple plate-shaped regions 301 having relatively high refractive indices in a region 302 with relatively low refractive indices. By having this regular internal structure, the light diffusion control unit 3 can strongly diffuse incident light that is incident on the surface of the light diffusion control unit 3 within a predetermined incident angle range, while simultaneously emitting it at a predetermined aperture angle. On the other hand, in the case of incident light outside the aforementioned incident angle range, it can transmit without diffusion, or emit it with weaker diffusion than the case of incident light within the incident angle range. Furthermore, the direction perpendicular to the long side direction of the plate-shaped regions 301 and existing on the surface of the light diffusion control unit 3 opposite to the light-transmitting imaging unit 2 (…) Figure 2 The direction represented by "D1" is set as the "first direction".

[0036] When the aerial imaging device 10 of this embodiment displays the desired image (real image) on the display surface of the display unit 1, it is able to, when observed from a predetermined observation point 5, achieve [the desired image]. Figure 1 The image (aerial image) formed by observing the above real image in the air is located at the position indicated by the symbol "4". In addition, in this specification, the surface at the position indicated by the symbol "4" is designated as the "aerial image observation surface".

[0037] Here, with conventional aerial imaging devices, sometimes while viewing aerial images, external light originating from external light sources can be seen. In particular, sometimes external light can be generated on the aerial image viewing surface of the light-transmitting imaging unit 2, thereby hindering a good view of the aerial images.

[0038] In this regard, the aerial imaging device 10 of this embodiment, by providing a light diffusion control unit 3, is able to suppress external light and view aerial images well. It is presumed that this effect is caused by the function of the light diffusion control unit 3, as described below. However, it is not limited to this function, nor does it rule out the possibility of other functions.

[0039] Based on various studies conducted by the inventors of this invention, it is speculated that the aforementioned external light originates from light incident from an external light source onto the translucent imaging unit, which then returns to the viewer's direction (hereinafter sometimes referred to as "return light"). It is speculated that, especially when the translucent imaging unit is a retrotransmission optical element as described later, such return light is light whose exit direction from an external light source incident on the interior of the retrotransmission optical element changes drastically within the retrotransmission optical element and exits from the viewer's side.

[0040] In the aerial imaging device 10 of this embodiment, a light diffusion control unit 3 is provided on the viewer-side surface of the light-transmitting imaging unit 2. With this configuration, light incident on the light-transmitting imaging unit 2 from an external light source diffuses and passes through the light diffusion control unit 3. This blurs backlighting and suppresses color distortion, thereby improving visibility. On the other hand, light from the display unit is directed to pass directly through the light diffusion control unit 3, enabling a clear display of the aerial image. As a result, the aerial imaging device 10 of this embodiment suppresses backlighting and the influence of external light, thus allowing for a good view of the aerial image.

[0041] 1. Display section

[0042] The display unit 1 constituting the aerial imaging device 10 of this embodiment is not particularly limited as long as it has a display surface that can display an image and emit light to the light-transmitting imaging unit 2 and the light diffusion control unit 3. For example, a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic electroluminescent (organic EL) display, etc., can be used as the display unit 1.

[0043] The positional relationship between the display unit 1, the light-transmitting imaging unit 2, and the light diffusion control unit 3 is not particularly limited. Preferably, as follows: Figure 1 As shown, the display unit 1 and the light-transmitting imaging unit 2 are sufficiently separated, with a space between them. Furthermore, it is preferable that the display unit 1 is positioned such that the display surface of the display unit 1 is not parallel to the surface of the light-transmitting imaging unit 2 opposite to the light-diffusion control unit 3. This positional relationship allows for better display of aerial images.

[0044] 2. Light-transmitting imaging unit

[0045] The light-transmitting imaging unit 2 constituting the aerial imaging device 10 of this embodiment is not particularly limited as long as it can transmit light from the display unit 1 and image the aerial image on a predetermined aerial image observation surface. Examples of such a light-transmitting imaging unit 2 include retro-transmitting optical elements that retro-transmit incident light.

[0046] While conventionally known retrotransmission optical elements can be used as retrotransmission optical elements, from the perspective of easily achieving good imaging of aerial images, it is preferable to use a retrotransmission optical element with a dihedral corner reflector array structure, or a retrotransmission optical element formed by stacking two layers having multiple reflective surfaces, and more preferably a retrotransmission optical element formed by stacking two layers having multiple reflective surfaces. In particular, in this retrotransmission optical element, it is preferable that in each of the two layers, the multiple reflective surfaces are arranged perpendicular to one surface of the retrotransmission optical element and spaced apart from each other by a predetermined interval, and that the two layers are stacked such that the reflective surface of one layer is orthogonal to the reflective surface of the other layer.

[0047] The thickness of the light-transmitting imaging portion 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. By keeping the thickness of the light-transmitting imaging portion 2 within the above range, the aerial imaging device 10 of this embodiment can more easily and clearly display aerial images.

[0048] 3. Light diffusion control unit

[0049] The light diffusion control unit 3 of the aerial imaging device 10 constituting this embodiment is not particularly limited as long as it has the aforementioned regular internal structure in the shape of louvers.

[0050] From the perspective of easily forming a regular internal structure, the light diffusion control part 3 is preferably a material formed by curing a light diffusion control part composition, which contains a high refractive index component and a low refractive index component having a lower refractive index than the high refractive index component. In particular, the high refractive index component and the low refractive index component preferably each have one or two polymerizable functional groups.

[0051] (1) High refractive index components

[0052] Preferred examples of high-refractive-index components include (meth)acrylates containing aromatic rings, and particularly preferred are (meth)acrylates containing multiple aromatic rings. Examples of (meth)acrylates containing multiple aromatic rings include biphenyl (meth)acrylate, naphthyl (meth)acrylate, anthracene (meth)acrylate, benzylidene (meth)acrylate, biphenyloxyalkyl (meth)acrylate, naphthoxyalkyl (meth)acrylate, anthraceneoxyalkyl (meth)acrylate, benzylidene (meth)acrylate, and compounds formed by substituting a portion of these compounds with halogens, alkyl groups, alkoxy groups, or haloalkyl groups. Among these, biphenyl (meth)acrylate is preferred from the perspective of easily forming a good regular internal structure; specifically, o-phenylphenoxyethyl acrylate and o-phenylphenoxyethoxyethyl acrylate are preferred. Furthermore, in this specification, (meth)acrylate refers to both acrylic acid and methacrylic acid. Other similar terms are also used.

[0053] 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. By keeping the molecular weight within this range, it is easy to form a light diffusion control section 3 with the desired regular internal structure. Furthermore, when 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 that theoretical molecular weight. However, when the theoretical molecular weight is difficult to determine because the high refractive index component is, for example, a polymer, the molecular weight of the high refractive index component refers to the weight-average molecular weight obtained as a value converted from standard polystyrene determined by gel permeation chromatography (GPC). Additionally, the method for determining the weight-average molecular weight in this specification refers to the value converted from standard polystyrene determined by this GPC method.

[0054] 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. By keeping the refractive index within the above range, it is easy to form a light diffusion control section 3 with the desired regular internal structure. Furthermore, the refractive index in this specification refers to the refractive index of a specified component before the light diffusion control section is cured with the composition, and this refractive index is a value measured based on JIS K0062:1992.

[0055] The content of the high refractive index component in the composition for the light diffusion control layer is preferably 25 to 400 parts by mass relative to 100 parts by mass of the low refractive index component, 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. By keeping this content within the above range, the regions from the high refractive index component and the regions from the low refractive index component exist in the desired proportion in the regular internal structure of the formed light diffusion control section 3, making it easy to form the desired regular internal structure.

[0056] (2) Low refractive index components

[0057] Preferred examples of low refractive index components include urethane (meth)acrylate, (meth)acrylic polymers having (meth)acryloyl groups in their side chains, silicone resins containing (meth)acryloyl groups, and unsaturated polyester resins. Among these, urethane (meth)acrylate is particularly preferred from the perspective of easily forming a well-defined, regular internal structure. More specifically, urethane (meth)acrylate formed from (a) a compound containing at least two isocyanate groups, (b) a polyalkylene glycol, and (c) a (meth)acrylate hydroxyalkyl ester is preferred.

[0058] Preferred examples of compounds containing at least two isocyanate groups as described in (a) above include aromatic polyisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-phenylenedimethylene diisocyanate, and 1,4-phenylenedimethylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; biuret forms and isocyanurate forms of these compounds; and adducts as reaction products with low-molecular-weight compounds containing active hydrogen such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Alicyclic polyisocyanates are preferred, and alicyclic diisocyanates are particularly preferred.

[0059] Preferred examples of the polyalkylene glycols in (b) above include polyethylene glycol, polypropylene glycol, polybutane glycol, and polyhexane glycol. Polypropylene glycol is preferred. Furthermore, the weight-average molecular weight of the polyalkylene glycols in (b) is preferably 2300 to 19500, particularly preferably 3000 to 14300, and even more preferably 4000 to 12300.

[0060] Preferred examples of (c)(meth)acrylate hydroxyalkyl esters include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, and 4-hydroxybutyl methacrylate. Among these, 2-hydroxyethyl methacrylate is preferred.

[0061] The synthesis of urethane (meth)acrylates using the components (a) to (c) above as materials can be carried out by conventional methods. In this case, from the perspective of efficiently synthesizing urethane (meth)acrylates, the molar ratio of components (a) to (c) is preferably (a):(b):(c) = 1 to 5:1:1 to 5, and particularly preferably 1 to 3:1:1 to 3.

[0062] 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 even more preferably 7,000 to 13,000. By keeping the weight-average molecular weight within the above range, it is easy to form a light diffusion control section 3 with the desired regular internal structure.

[0063] 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. By keeping the refractive index within the above range, it is easy to form a light diffusion control section 3 with the desired regular internal structure.

[0064] (3) Other additives

[0065] In addition to high-refractive-index and low-refractive-index components, the aforementioned composition for light diffusion control may also contain other additives. Examples of such additives include multifunctional monomers, photopolymerization initiators, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, polymerization accelerators, polymerization inhibitors, infrared absorbers, plasticizers, diluents, and leveling agents.

[0066] The light diffusion control layer composition preferably contains a photopolymerization initiator. This allows for the easy and effective formation of the light diffusion control layer 3 with the desired regular internal structure.

[0067] Examples of photopolymerization initiators 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-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane-1-one, 4-(2-hydroxyethoxy)phenyl-2-( (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, benzoyladium dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligomeric [2-hydroxy-2-methyl]-1-[4-(1-methylvinyl)phenyl]propane], etc. These photopolymerization initiators can be used alone or in combination of two or more.

[0068] When using a photopolymerization initiator, the content of the photopolymerization initiator in the composition for the light diffusion control section is preferably 0.2 to 20 parts by weight, more preferably 0.5 to 16 parts by weight, particularly preferably 1 to 13 parts by weight, and even more preferably 1 to 10 parts by weight, relative to a total of 100 parts by weight of the high-refractive-index component and the low-refractive-index component. By setting this content within the above range, the light diffusion control section 3 having the desired regular internal structure can be easily and effectively formed.

[0069] (4) Preparation of the composition for the light diffusion control section

[0070] The composition for light diffusion control can be prepared by uniformly mixing the aforementioned high refractive index component and low refractive index component, as well as other additives such as photopolymerization initiators and ultraviolet absorbers as required.

[0071] During the above mixing process, the mixture can be heated to a temperature of 40°C to 80°C while stirring to obtain a uniform composition for light diffusion control. Furthermore, a diluent can be added and mixed to adjust the viscosity of the obtained composition for light diffusion control to the desired level.

[0072] (5) Internal structure of the rule

[0073] As described above, the light diffusion control unit 3 preferably has a regular internal structure in the shape of a louver, having a plurality of plate-shaped regions 301 with relatively high refractive index in the region 302 with relatively low refractive index.

[0074] In the light diffusion control unit 3, preferably each plate-shaped region 301 is orthogonal to the surface of the light diffusion control unit 3. Therefore, the aerial imaging device 10 of this embodiment can easily suppress the influence of external light and can more easily display aerial images more clearly.

[0075] In addition, such as Figure 2 As shown, the plate-shaped region 301 can also be tilted. In this case, the tilt angle is preferably 0° or more relative to the thickness direction of the light diffusion control unit 3. Furthermore, the aforementioned angle is preferably 30° or less, more preferably 28° or less, particularly preferably 25° or less, further preferably 20° or less, and most preferably 10° or less. By tilting the plate-shaped region 301 at the aforementioned angle, the aerial imaging device 10 of this embodiment can easily suppress external light and can easily display aerial images more clearly.

[0076] The light diffusion control unit 3 may also have the following functions: Figure 2 Structures other than the regular internal structure shown. For example, the plate-shaped region 301 may also bend midway in the thickness direction of the light diffusion control section 3. Furthermore, the light diffusion control section 3 may also be stacked with two or more layers of regular internal structures formed by arranging the plate-shaped regions 301.

[0077] In particular, in the aerial imaging device 10 of this embodiment, the light diffusion control unit 3 is preferably... Figure 4 The membrane stack 3a shown in (a) is or Figure 4 The single film 3b is shown in (b) above. This film stack 3a is formed by stacking at least two films 31 with a regular, louver-like internal structure, each having multiple plate-like regions 301 with relatively high refractive indices in regions with relatively low refractive indices. The single film 3b is formed by stacking at least two segments of a regular, louver-like internal structure having multiple plate-like regions 301 with relatively high refractive indices in regions with relatively low refractive indices.

[0078] By making the light diffusion control unit 3 a film laminate 3a or a single film 3b as described above, it becomes a regular internal structure with two or more louver-like sections, making it easier to suppress the influence of external light.

[0079] Furthermore, the aerial imaging device 10 of this embodiment is preferably as follows: Figure 5As shown, the light-transmitting imaging unit 2 includes a second light diffusion control unit 3' disposed on the display surface 1 side. This second light diffusion control unit 3', like the light diffusion control unit 3 (hereinafter sometimes referred to as the "first light diffusion control unit 3") stacked on the surface of the light-transmitting imaging unit 2 opposite to the display surface 1, diffuses or transmits light incident upon it according to its incident angle, and has a regular internal structure resembling louvers with multiple plate-like regions of relatively high refractive index in regions with relatively low refractive index.

[0080] As described above, the aerial imaging device 10 equipped with the first light diffusion control unit 3 and the second light diffusion control unit 3' can effectively suppress the influence of external light mainly through the function of the first light diffusion control unit 3, and can effectively suppress the generation of ghosting mainly through the function of the second light diffusion control unit 3'.

[0081] Here, ghosting refers to an image that reflects a real image but is still displayed around the aerial image on the aerial image viewing surface 5, even though it is not displayed on the display surface of the display unit 1. The second light diffusion control unit 3' ensures that the light used to form the aerial image reaches the light-transmitting imaging unit 2 well, while also ensuring that the light used to form ghosting reaches the light-transmitting imaging unit 2 in a diffused state. As a result, the viewer can clearly see the aerial image, but is less likely to see ghosting.

[0082] Furthermore, the materials constituting the above-mentioned film laminate 3a, single film 3b, and second light diffusion control unit 3' can be the same as the material of the first light diffusion control unit 3.

[0083] (6) Thickness of the light diffusion control section

[0084] The thickness of the light diffusion control unit 3 is preferably 1 to 500 μm, more preferably 10 to 300 μm, particularly preferably 50 to 250 μm, further preferably 80 to 200 μm, and especially preferably 100 to 170 μm. By keeping the thickness within the above range, the aerial imaging device 10 of this embodiment can easily suppress the influence of external light and display aerial images more easily and clearly.

[0085] also, Figure 5 The preferred thickness range of the second light diffusion control unit 3' of the aerial imaging device 10 shown is also as described above.

[0086] On the other hand, in the light diffusion control unit 3, such as Figure 4In the case shown in (a) where the film stack 3a is the film layer, the thickness of the film 31 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 preferably 100 to 160 μm. Therefore, the aerial imaging device 10 of this embodiment can easily and effectively suppress the influence of external light.

[0087] Furthermore, in the light diffusion control section 3, such as Figure 4 In the case shown in (b), where a single film 3b is used, the thickness of the single film 3b is preferably 2 to 1000 μm, more preferably 20 to 600 μm, particularly preferably 100 to 500 μm, and even more preferably 160 to 400 μm, with 200 to 320 μm being the most preferred. Therefore, the aerial imaging device 10 of this embodiment can easily and effectively suppress the influence of external light.

[0088] (7) Method for forming the light diffusion control section

[0089] There is no particular limitation on the method of forming the light diffusion control unit 3, and it can be formed by conventionally known methods.

[0090] For example, after coating one side of the aforementioned light diffusion control layer composition to form a coating film, a release liner (particularly the release side) is attached to the side of the coating film opposite to the process sheet. Then, the coating film is cured by irradiating it with active energy rays through the process sheet or the release liner, thus forming the light diffusion control section 3. Therefore, by stacking the release liner on the coating film, maintaining the distance between the release liner and the process sheet, and preventing the coating film from being crushed, it is easy to form a light diffusion control section 3 with uniform thickness and a desired regular internal structure.

[0091] As release sheets, for example, 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)acrylate copolymer films, ethylene-(meth)acrylate copolymer films, polystyrene films, polycarbonate films, polyimide films, fluoropolymer films, and other resin films can be used. Furthermore, cross-linked films of these films can also be used. Further, laminated films of these films can also be used.

[0092] The release surface of the glass slide is preferably subjected to a release treatment. Preferably, the release agent used in the release treatment is an alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, or paraffin-based release agent.

[0093] There is no particular limitation on the thickness of the release sheet, but from the perspective of excellent operability and good protection of the light diffusion control unit 3 until use, it is preferably 20 to 200 μm, more preferably 30 to 100 μm.

[0094] As a process sheet, a resin film, cross-linked film, or laminated film thereof, which are used as the release sheet described above, can be used. Alternatively, the release sheet described above can also be used as a process sheet.

[0095] From the perspective of easily forming the required light diffusion control section 3 and ensuring good protection of the light diffusion control section 3 until use, the thickness of the process sheet is preferably 20~250μm, more preferably 30~200μm.

[0096] Examples of the coating methods described above include blade coating, roller coating, bar coating, doctor blade coating, die coating, and gravure coating. Furthermore, the composition for the light diffusion control section can be diluted with a solvent as needed.

[0097] The coating can be irradiated with active energy rays using conventionally known methods. For example, a linear light source can be used as the source of the active energy rays, irradiating the surface of the object with a strip-shaped (approximately linear) beam that is random in the width direction (TD direction) and slightly parallel in the transport direction (MD direction). Furthermore, by adjusting the irradiation angle of the aforementioned beam, the tilt angle of the plate-shaped region 301 can also be adjusted.

[0098] Furthermore, the aforementioned active energy rays refer to active energy rays containing energy quanta within electromagnetic waves or charged particle beams; specifically, examples include ultraviolet light and electron beams. Among active energy rays, ultraviolet light is particularly preferred as it is easy to manipulate and readily forms the desired regular internal structure.

[0099] When ultraviolet light is used as an active energy ray, the peak illuminance on the coating surface is preferably set to 0.1~200 mW / cm² as the irradiation condition. 2 Furthermore, it is preferable to set the cumulative light intensity on the coating surface to 5~300 mJ / cm. 2 Furthermore, it is preferable to set the relative movement speed of the active energy ray source relative to the irradiated object to be 0.1~10 m / min.

[0100] Furthermore, from the perspective of achieving more reliable curing, it is preferable to irradiate with conventional active energy rays (active energy rays or scattered light that have not been converted into parallel light, ribbon light, etc.) after performing curing using the aforementioned ribbon light.

[0101] In addition, the film 31 constituting the film stack 3a and the second light diffusion control unit 3' can be manufactured in the same manner as described above.

[0102] On the other hand, as a method for forming the single film 3b, for example, after coating the light diffusion control composition onto one side of a process sheet to form a coating film, a release sheet (particularly the release surface) is attached to the side of the coating film opposite to the process sheet. Then, the coating film is cured by irradiating it with active energy rays through the process sheet or the release sheet. Further, the release sheet is peeled off from the laminate of the process sheet, the cured film, and the release sheet formed in the above manner, and the light diffusion control composition is coated onto its exposed surface to form a coating film. Then, a release sheet (particularly the release surface) is attached to the side of the coating film opposite to the process sheet. Then, the coating film is cured by irradiating it with active energy rays through the process sheet or the release sheet, thereby forming the light diffusion control film 3b.

[0103] 4. Other constituent elements

[0104] The aerial imaging device 10 of this embodiment may also include components other than the display unit 1, the light-transmitting imaging unit 2, and the light diffusion control unit 3 described above. In particular, the aerial imaging device 10 of this embodiment preferably includes a frame for fixing and housing the display unit 1, the light-transmitting imaging unit 2, and the light diffusion control unit 3 in a predetermined position.

[0105] The material, shape, and size of the frame can be appropriately selected according to the application and purpose. In particular, the frame is preferably made of a light-shielding material, which can prevent light from the display unit 1 from accidentally leaking to the outside and can prevent external light from unintentionally intruding into the light path from the display unit 1 to the light-transmitting imaging unit 2.

[0106] 5. The positional relationship of each element

[0107] In the aerial imaging device 10 of this embodiment, in the envisioned Figure 2 When the first direction, indicated by "D1", is considered as the second direction, and the direction parallel to the plane perpendicular to both the display surface of the display unit 1 and one surface of the light-transmitting imaging unit 2, and existing in the plane on the side of the light-transmitting imaging unit 2 of the light diffusion control unit 3, is also considered as the second direction, the acute angle formed by the first direction and the second direction is preferably 0° or more and 90° or less. Regardless of the acute angle, by considering the incident angle of the light diffusion control unit 3, which includes D1 and is perpendicular to the plane of the light diffusion control unit 3, the aerial imaging device 10 of this embodiment can easily suppress the influence of external light and can easily display aerial images more clearly.

[0108] 6. Manufacturing method of aerial imaging device

[0109] The manufacturing method of the aerial imaging device 10 in this embodiment is not particularly limited. For example, after preparing the display unit 1, the light-transmitting imaging unit 2 and the light diffusion control unit 3 respectively, the aerial imaging device 10 can be obtained by setting the display unit 1 at a predetermined position in the frame and setting a laminate of the light-transmitting imaging unit 2 and the light diffusion control unit 3.

[0110] 7. How to use the aerial imaging device

[0111] The aerial imaging device 10 of this embodiment can be used as a display device for displaying arbitrary images, videos, etc. in the air. Its specific usage is not limited, and it can be used in the same manner as conventionally known display devices.

[0112] [Layered Body]

[0113] The laminated body of this embodiment is a structure that omits the display unit 1 from the aerial imaging device 10. That is, the laminated body of this embodiment includes: a light-transmitting imaging unit 2 that images light incident from one side at a position on the other side, and a light diffusion control unit 3 laminated on one side of the light-transmitting imaging unit 2. The detailed composition and structure of the light-transmitting imaging unit 2 and the light diffusion control unit 3 are as described above.

[0114] Furthermore, the light diffusion control unit 3 of the laminate in this embodiment can be Figure 4 The membrane stack 3a shown in (a) can also be... Figure 4 The single membrane 3b is shown in (b) of this embodiment. Furthermore, the laminate in this embodiment can also be... Figure 5 The structure shown is derived from the aerial imaging device 10 equipped with the second light diffusion control unit 3', omitting the display unit 1.

[0115] The laminated body of this embodiment is obtained by laminating the light-transmitting imaging unit 2 and the light diffusion control unit 3 after preparing the light-transmitting imaging unit 2 and the light diffusion control unit 3 respectively. Furthermore, the laminated body of this embodiment can also be used to form the aerial imaging device 10 of this embodiment. That is, the aerial imaging device 10 of this embodiment can be obtained by arranging the display unit 1 at a predetermined position on the laminated body of this embodiment.

[0116] Furthermore, in this specification, when denoted as "X~Y" (where X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less," and also includes the meaning of "preferably greater than X" or "preferably less than Y." Additionally, when denoted as "X or more" (where X is any number), unless otherwise specified, it includes the meaning of "preferably greater than X," and when denoted as "Y or less" (where Y is any number), unless otherwise specified, it also includes the meaning of "preferably less than Y."

[0117] The embodiments described above are provided for the purpose of understanding the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments are intended to include all design changes, equivalents, etc., that fall within the scope of the present invention.

[0118] Example

[0119] The present invention will now be described in more detail through examples, etc., but the scope of the present invention is not limited to these examples, etc.

[0120] [Example 1]

[0121] As the light diffusion control unit, preparation Figure 2 The element shown is formed by a louver structure with multiple parallel plate-like regions arranged at predetermined intervals inside (manufactured by LINTEC Corporation, product name "WINCOSX-1515", internal refractive index distribution structure diffusion element, tilted without louver structure, diffusion angle region: ±15°, thickness 165μm). Furthermore, the aforementioned diffusion angle region refers to the angular range of diffused light obtained when a point light source is fixed at the angle at which the incident light diffuses most significantly relative to the element.

[0122] In addition, as a light-transmitting imaging unit, a retrotransmission optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200mm × width 200mm × thickness 6.3mm) is prepared to be formed by stacking two layers with multiple reflective surfaces.

[0123] Then, an aerial imaging device sample is obtained by overlaying one surface of the light diffusion control unit onto one surface of the light-transmitting imaging unit. Furthermore, this aerial imaging device sample omits the display unit. This is because, in the test of Test Example 1 described later, it is not necessary to activate the display unit to form an aerial image.

[0124] [Comparative Example 1]

[0125] An aerial imaging device sample was obtained in the same manner as in Example 1, except that the light diffusion control unit was not used. That is, only the above-described light-transmitting imaging unit was used as the aerial imaging device sample of Comparative Example 1.

[0126] [Experimental Example 1] (Evaluation of the Influence of External Light)

[0127] The aerial imaging device samples of Example 1 and Comparative Example 1 were placed on a black cloth. For the aerial imaging device sample of Example 1, the surface of the light-transmitting imaging section was brought into contact with the black cloth. For the aerial imaging device sample of Comparative Example 1, any surface was brought into contact with the black cloth.

[0128] Next, with the observer standing in front of the aerial imaging device sample, the sample is positioned with the external light source (a fluorescent lamp mounted on the ceiling) to the observer's left. More specifically, when viewing one side of the aerial imaging device sample from above, the sample is positioned such that a line passing through the sample and the observer is approximately orthogonal to a line passing through the sample and the external light source. Then, from an observation point where the angle (elevation angle) between the line passing through the observer's eye (observation point) and the center of the sample is 45° relative to the main surface of the sample, the external light seen on the main surface of the aerial imaging device sample is observed.

[0129] Furthermore, for the aerial imaging device sample of Example 1, the line passing through the center of the aerial imaging device sample and the observer's line of sight is aligned with the light diffusion control unit. Figure 2 The aerial imaging device sample is configured in a manner parallel to the first direction D1, as shown.

[0130] The results of the above observations (when the external light source is located on the left) are shown below. Figure 3 (a) Furthermore, the result of observing in the same manner as described above (with the external light source positioned to the observer's right) is shown below, except that the position of the external light source is changed to the observer's right. Figure 3 (b) in the middle.

[0131] according to Figure 3 As can be clearly seen in (a) and (b) of Comparative Example 1, the outline of the fluorescent lamp, which forms the external light source, can be clearly identified, while the outline of the fluorescent lamp is not clear in the aerial imaging device sample of Example 1. Therefore, it can be seen that the aerial imaging device sample of Example 1 can suppress the influence of external light sources (e.g., the influence of backlighting) and the influence of external light, and can effectively view aerial images.

[0132] [Manufacturing Example 1] (Light Diffusion Control Film A) (10° tilt, no bending)

[0133] 1. Preparation of compositions for light diffusion control films

[0134] A composition for light diffusion control film is obtained by heating and mixing 40 parts by weight (conversion value of solid components; the same below) of polyether urethane methacrylate with a weight average molecular weight of 9,900 as a low refractive index component (obtained by reacting polypropylene glycol, isophorone diisocyanate and 2-hydroxyethyl methacrylate), 60 parts by weight of o-phenylphenoxyethoxyethyl acrylate with a molecular weight of 268 as a high refractive index component, and 8 parts by weight of 2-hydroxy-2-methyl-1-phenylpropane-1-one as a photopolymerization initiator, at 80°C.

[0135] Here, the aforementioned weight-average molecular weight (Mw) is the weight-average molecular weight converted from standard polystyrene determined using gel permeation chromatography (GPC) under the following conditions (GPC determination).

[0136] <Measurement Conditions>

[0137] • Measuring apparatus: Manufactured by TOSOH CORPORATION, HLC-8320

[0138] • GPC column (passes through in the following order): Manufactured by TOSOH CORPORATION

[0139] TSK gel superH-H

[0140] TSK gel superHM-H

[0141] TSK gel superH2000

[0142] • Determination solvent: tetrahydrofuran

[0143] • Measurement temperature: 40℃

[0144] 2. Formation of light diffusion control film

[0145] The obtained light diffusion control film is coated with the composition onto the release surface of a release sheet S1 (thickness: 188 μm), which is a process sheet for which one side of a polyethylene terephthalate film has been treated with a silicone-based release agent, to form a coating. This yields a laminate consisting of the coating and the process sheet. Next, the release surface of a release sheet S2 (thickness: 38 μm), which has also been treated with a silicone-based release agent, is laminated onto the coating side of this laminate, thereby obtaining a laminate formed by sequentially laminating the process sheet, the coating, and the release sheet S2.

[0146] Next, the obtained laminate is placed on a conveyor belt. At this time, the surface of the release sheet S2 in the laminate is positioned upwards, and the length direction of both the process sheet and the release sheet S2 is parallel to the travel direction of the conveyor belt. Next, an ultraviolet irradiation device (manufactured by EYEGRAPHICS COMPANY, product name "ECS-4011GX") with a focusing mirror attached to a linear high-pressure mercury lamp is installed on the conveyor belt carrying the laminate. This device can irradiate a single point on the object being irradiated with ultraviolet light scattered in a ribbon-like (almost linear) pattern. Furthermore, when installing the above device, the ultraviolet irradiation device is positioned such that the long side of the high-pressure mercury lamp is orthogonal to the conveying direction of the conveyor belt.

[0147] Furthermore, when viewed from the length of the high-pressure mercury lamp, the irradiation angle of the ultraviolet light irradiated from the high-pressure mercury lamp relative to the laminate is set to -10°, using the normal to the surface of the laminate as a reference. Here, the irradiation angle refers to the acute angle formed by the ultraviolet light relative to the normal to the surface of the laminate and the ultraviolet light when irradiating the downstream side of the conveyor belt, with a positive sign when irradiating the upstream side of the conveyor belt; and the acute angle formed by the ultraviolet light relative to the normal to the surface of the laminate and the ultraviolet light when irradiating the upstream side of the conveyor belt, with a negative sign.

[0148] Then, the conveyor belt is started, moving the laminate at a speed of 1.0 m / min while maintaining a peak illuminance of 2.5 mW / cm² on the coating surface. 2 The cumulative light intensity is 40.0 mJ / cm². 2 Under certain conditions, ultraviolet light is irradiated through the aforementioned release sheet, thereby curing the coating in the laminate (for convenience, this curing is sometimes referred to as "one-time curing").

[0149] Next, while moving it at a speed of 1.0 m / min, a peak illuminance of 190 mW / cm² was applied. 2 The cumulative light intensity is 180 mJ / cm². 2 Under the specified conditions, ultraviolet light (scattered light) is irradiated onto the coating film through the release liner S2, thereby curing the coating film in the laminate (for convenience, this curing is sometimes referred to as "secondary curing"). Furthermore, the aforementioned peak illuminance and cumulative light intensity are values ​​obtained by placing a UV illuminance meter (manufactured by EYE GRAPHICS COMPANY, product name "EYE UV cumulant illuminance meter UVPF-A1") equipped with a light receiver at the location of the coating film and measuring the values.

[0150] Through the above-mentioned primary and secondary curing processes, the coating is fully cured and becomes the light diffusion control film A. Thus, a laminate is obtained by sequentially stacking the process sheet, the 140 μm thick light diffusion control film A, and the release sheet S2.

[0151] Furthermore, when the cross-section of the formed light diffusion control film A is observed under a microscope, it is confirmed that inside the light diffusion control film A, such as Figure 2 As shown, a louver structure is formed (multiple plate-shaped regions 301 are arranged in parallel at specified intervals). The angle between the main surface of the louver structure and the acute angle formed by the normal to the light diffusion control film A is approximately 7°.

[0152] [Manufacturing Example 2] (Light Diffusion Control Film B) (15° tilt, no bending)

[0153] Except for changing the irradiation angle of ultraviolet light to -15°, a laminate with light diffusion control film B was obtained in the same manner as in manufacturing example 1.

[0154] Furthermore, during microscopic observation of the cross-section of the formed light diffusion control film B, it was confirmed that a louver structure (multiple plate-like regions 301 arranged in parallel at predetermined intervals and bent in the film thickness direction) was formed inside the light diffusion control film B. The angle between the main surface of the louver structure and the normal to the light diffusion control film B is approximately 10°.

[0155] [Manufacturing Example 3] (Light Diffusion Control Film C) (5° tilt, with bending)

[0156] A composition for light diffusion control film was obtained by adding 40 parts by weight (conversion value of solid content; the same below) of polyether urethane methacrylate with 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 weight of o-phenylphenoxyethoxyethyl acrylate with a molecular weight of 268 as a high refractive index component, 8 parts by weight of 2-hydroxy-2-methyl-1-phenylpropane-1-one as a photopolymerization initiator, 0.5 parts by weight of an acrylic leveling agent (manufactured by BYK Japan KK, product name "BYK-361N"), and 0.08 parts by weight of a benzotriazole compound (manufactured by BASF, product name "Tinuvin 384-2") as a UV absorber, and then heating and mixing at 80°C.

[0157] Except for using the light diffusion control film composition obtained in the manner described above and changing the irradiation angle of ultraviolet light to -5°, a laminate having the light diffusion control film C was obtained in the same manner as in Manufacturing Example 1.

[0158] Furthermore, during microscopic observation of the cross-section of the formed light diffusion control film C, it was confirmed that a louver structure (a louver structure in which multiple plate-like regions 301 are arranged in parallel at specified intervals and are bent in the film thickness direction) was formed inside the light diffusion control film C. The angle between the main surface of the louver structure and the normal to the light diffusion control film C is approximately 3°.

[0159] [Example 2]

[0160] Peel off the laminate obtained from Manufacturing Example 1, and then use a 25μm acrylic transparent adhesive to laminate the exposed surface of the light diffusion control film A onto one surface of a retrotransmission optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200mm × width 200mm × thickness 6.3mm), which is formed by laminating two layers with multiple reflective surfaces to serve as a light-transmitting imaging part.

[0161] Furthermore, the process sheet is peeled off from the laminate obtained in Manufacturing Example 2, and the exposed surface of the light diffusion control film B is laminated onto the surface of the peeled sheet on the side of the light diffusion control film A in the laminate of the light diffusion control film A and the light-transmitting imaging part obtained in the above manner using a 25 μm acrylic transparent adhesive. At this time, the first direction (perpendicular to the length direction of the plate-like region and existing in the plane of the light diffusion control part (light diffusion control film) opposite to the light-transmitting imaging part) is... Figure 3 The light diffusion control film (D1) is stacked between the light diffusion control film A and the light diffusion control film B in a manner in which multiple plate-shaped regions 301 are tilted in the same direction. Thus, a light diffusion control section (D1) is obtained, which is formed by stacking the light diffusion control film B and the light diffusion control film A. Figure 4 The sample of an aerial imaging device includes a film laminate 3a shown in (a) and a light-transmitting imaging section on the side of the light diffusion control film A of the light diffusion control section.

[0162] As shown in Test Example 1 above, the influence of external light was evaluated on the obtained aerial imaging device sample. The results show that the aerial imaging device sample of Example 2 can suppress the influence of external light sources (e.g., the influence of backlight) and can suppress the influence of external light, and can view aerial images well.

[0163] [Example 3]

[0164] Peel off the laminate obtained from Manufacturing Example 1, and then use a 25μm acrylic transparent adhesive to laminate the exposed surface of the light diffusion control film A onto one surface of a retrotransmission optical element (manufactured by Asukanet Co., Ltd., product name "ASKA3D-200NT", length 200mm × width 200mm × thickness 6.3mm), which is formed by laminating two layers with multiple reflective surfaces to serve as a light-transmitting imaging part.

[0165] Furthermore, the laminate obtained from Manufacturing Example 3 is peeled off, and the exposed surface of the light diffusion control film C is laminated onto the light-transmitting imaging portion of the laminate of the light diffusion control film A and the light-transmitting imaging portion obtained in the above manner using a 25 μm acrylic transparent adhesive. At this time, the first direction (perpendicular to the length direction of the plate-like region and existing in the plane of the light diffusion control portion (light diffusion control film) opposite to the light-transmitting imaging portion) is... Figure 3 D1) The light diffusion control film A and the light diffusion control film C are stacked in a manner in which multiple plate-shaped regions 301 are tilted in the same direction. Thus, an aerial imaging device sample is obtained by sequentially stacking the light diffusion control film A, the light-transmitting imaging part, and the light diffusion control film C.

[0166] As shown in Test Example 1 above, the influence of external light was evaluated on the obtained aerial imaging device sample. The results show that the aerial imaging device sample of Example 3 can suppress the influence of external light sources (e.g., the influence of backlight) and the influence of external light, and can view aerial images well.

[0167] Furthermore, the suppression of ghosting was evaluated on the obtained aerial imaging device sample, as shown in Test Example 2 below. The results show that the aerial imaging device sample of Example 3 can effectively suppress the occurrence of ghosting and can clearly view aerial images.

[0168] [Experimental Example 2] (Evaluation of Ghosting Suppression)

[0169] The aerial imaging device sample manufactured in Example 3 is placed on a predetermined frame with its main surface horizontal and the side of the light diffusion control film C facing downwards. Furthermore, as a display unit, the screen of a laptop computer is positioned within the frame in a stacked configuration facing the light diffusion control unit and the light-transmitting imaging unit.

[0170] When the display unit is configured, the angle formed between the display surface of the display unit and the main surface of the light-transmitting imaging unit is 45°. In addition, the frame blocks the light emitted by the display unit so that it does not escape to the outside from any part other than the aerial imaging device sample.

[0171] The aerial imaging device is formed by arranging the aerial imaging device sample and the display unit within a frame using the above methods.

[0172] Then, by displaying an image with a length of 70mm and a width of 100mm on the display unit to generate an aerial image, the situation of ghosting suppression is evaluated.

[0173] Industrial applicability

[0174] The aerial imaging device of the present invention can be used as a display for showing aerial images, etc.

[0175] Explanation of reference numerals in the attached figures

[0176] 10: Aerial imaging device; 1: Display unit; 2: Transmitting imaging unit; 3, 3': Light diffusion control unit; 301: Plate-shaped area; 302: Area with relatively low refractive index; 3a: Film stack; 31: Film; 3b: Single film; 4: Aerial image observation surface; 5: Observation point.

Claims

1. An aerial imaging device, characterized in that, have: A display unit having a display surface from which light is emitted; A light-transmitting imaging unit is disposed on the display surface side of the display unit and transmits light to form an image at a position opposite to the display unit; and A light diffusion control unit is stacked on the side of the light-transmitting imaging unit opposite to the display unit. The light diffusion control unit causes light incident upon it to diffuse or transmit according to its incident angle. The light diffusion control unit has a regular internal structure in the shape of louvers, and this regular internal structure in the shape of louvers has multiple plate-shaped regions with relatively high refractive indices in the region with relatively low refractive index.

2. The aerial imaging device according to claim 1, characterized in that, The display unit is arranged such that the display surface is not parallel to the surface of the light-transmitting imaging unit that is opposite to the light-diffusing control unit.

3. The aerial imaging device according to claim 2, characterized in that, When a first direction is defined as a direction perpendicular to the long side of the plate-shaped region and existing in the plane on the side of the light-transmitting imaging portion of the light diffusion control unit, and a second direction is defined as a plane parallel to both the display surface and one surface of the light-transmitting imaging portion and existing in the plane on the side of the light diffusion control unit,... The acute angle formed by the first direction and the second direction is greater than 0° and less than 90°.

4. The aerial imaging device according to claim 1, characterized in that, When the first direction is defined as the direction perpendicular to the long side of the plate-shaped region and existing in the plane on the side of the light-transmitting imaging portion of the light diffusion control portion, Each of the plate-shaped regions is inclined in the first direction within the light diffusion control unit.

5. The aerial imaging device according to claim 4, characterized in that, The tilt angle of the plate-shaped region is 0° or more and 30° or less relative to the thickness direction of the light diffusion control unit.

6. The aerial imaging device according to claim 1, characterized in that, The light diffusion control unit is a film stack or a single film. The film laminate is formed by stacking at least two films with a regular internal structure resembling louvers. This regular internal structure has multiple plate-like regions with relatively high refractive indices in regions with relatively low refractive indices. The single membrane is formed by stacking at least two louver-like regular internal structures that have multiple plate-like regions with relatively high refractive indices in regions with relatively low refractive indices.

7. The aerial imaging device according to claim 1, characterized in that, The aerial imaging device includes a second light diffusion control unit, which is disposed on the display surface side of the light-transmitting imaging unit. The second light diffusion control unit causes light incident upon it to diffuse or transmit according to its incident angle. The second light diffusion control unit has a regular internal structure in the shape of louvers, and this regular internal structure in the shape of louvers has multiple plate-shaped regions with relatively high refractive indices in the region with relatively low refractive index.

8. The aerial imaging device according to claim 1, characterized in that, The light-transmitting imaging unit has a retrotransmission optical element that enables incident light to be transmitted in reverse.

9. The aerial imaging device according to claim 8, characterized in that, The retrotransmission optical element is a component formed by stacking two layers with multiple reflective surfaces. In each of the two layers, the plurality of reflective surfaces are perpendicular to one surface of the retrotransmission optical element and arranged at predetermined intervals from each other. The two layers are stacked in such a manner that the reflective surface of one layer is orthogonal to the reflective surface of the other layer.

10. A laminated body, characterized in that, have: A light-transmitting imaging section that images light incident from one side onto the position of light on the other side; and A light diffusion control unit is stacked on one side of the light-transmitting imaging unit. The light diffusion control unit causes light incident upon it to diffuse or transmit according to its incident angle. The light diffusion control unit has a regular internal structure in the shape of louvers, and this regular internal structure in the shape of louvers has multiple plate-shaped regions with relatively high refractive indices in the region with relatively low refractive index.

11. The laminate according to claim 10, characterized in that, The light diffusion control unit is a film stack or a single film. The film laminate is formed by stacking at least two films with a regular internal structure resembling louvers. This regular internal structure has multiple plate-like regions with relatively high refractive indices in regions with relatively low refractive indices. The single membrane is formed by stacking at least two louver-like regular internal structures that have multiple plate-like regions with relatively high refractive indices in regions with relatively low refractive indices.

12. The laminate according to claim 10, characterized in that, The laminate includes a second light diffusion control unit, which is disposed on the side of the light-transmitting imaging unit opposite to the light diffusion control unit. The second light diffusion control unit causes light incident upon it to diffuse or transmit according to its incident angle. The second light diffusion control unit has a regular internal structure in the shape of louvers, and this regular internal structure in the shape of louvers has multiple plate-shaped regions with relatively high refractive indices in the region with relatively low refractive index.

Images