JP2018059965A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device having sufficient visibility thanks to superiority in improvement in a contrast, image burring prevention, luminance and a viewing angle, as sufficiently reducing an influence of external light incident inside the displace device at a prescribed angle through a window shield (for example, front glass), or a combiner or the like.SOLUTION: A display device, which irradiates a translucent member with display light representing a display image, and visibly displays the display image as a virtual image, comprises at least: a housing that is arranged below the translucent member; a light irradiation unit that is provided inside the housing and irradiates the display light; and an anisotropy optical film that includes at least an anisotropy light diffusion layer of which linear transmittance varies due to an angle of incident light of the display light or external light, and which has a matrix area and a columnar area serving as a plurality of columnar structures. The anisotropy optical film is arranged at a part of the housing located on an optical path of the display light between the light irradiation unit and the translucent member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device that can be mounted on a moving body or the like and that allows a virtual image of the display image to be visually recognized by irradiating a windshield or the like such as the moving body with the display image.

  2. Description of the Related Art Conventionally, various means have been used as information providing means for providing driving information such as route guidance and obstacle warning to a passenger of a moving body such as a vehicle. For example, display on a liquid crystal display installed on a moving body, sound output from a speaker, and the like. In recent years, a head-up display (HUD) device is mounted on a vehicle or the like as one of such information providing means.

  In the head-up display device, a device main body is generally arranged inside an instrument panel of a vehicle. The display light representing the display image displayed on the display unit inside the apparatus main body is called a vehicle windshield (front glass) or combiner via an optical path including a reflecting member such as a magnifying mirror. Irradiation (projection, projection) is performed toward an irradiation area such as an optical member (half mirror), and a virtual image is formed at a predetermined distance when viewed from the viewpoint position of the driver.

  As a result, when the driver looks forward in a normal driving posture, he / she visually recognizes a display image irradiated (projected) by the head-up display device together with a part of the vehicle body and the front scenery seen through the windshield. can do. The display image visually recognized by the driver is formed as a virtual image in front of the windshield surface, for example, at a distance of about several meters from the viewpoint, so the driver should adjust his eyes while driving. It is possible to simultaneously recognize the display image of the head-up display together with the scenery in front.

For example, Patent Document 1 discloses a related art related to a head-up display device for a vehicle. Patent Document 1 discloses a technique in which a diffusion layer having a reflection directivity is stacked on a reflection mirror in order to provide a head-up display device with good visibility even under bright external light conditions.

JP 2010-256867 A

  A head-up display device for a vehicle generally displays a display image of display light so that a virtual image seen from the position of the driver's viewpoint forms an image in front of a windshield (for example, front glass) or a combiner of the vehicle. Irradiate (project, project). Therefore, when the driver who drives the vehicle looks forward through a windshield (for example, windshield) or a combiner, an object such as a landscape in front or a part of the vehicle body (for example, a hood) overlaps. In the state, the display image of the head-up display device can be visually recognized as a virtual image.

  However, for example, in a situation where strong external light from the sun arrives, such as during the daytime in fine weather, the amount of external light is larger than the amount of virtual image displayed by the head-up display device. Under the influence of light, it becomes difficult to visually recognize the display of the virtual image. Therefore, for example, as disclosed in Patent Document 1, it may be effective to suppress the influence of external light by laminating a diffusion layer having reflection directivity on a reflection mirror.

  However, since the head-up display device performs display using a virtual image that has been irradiated (projected, projected), for example, when the intensity of external light is very high, such as during daytime in fine weather, a windshield (eg, windshield) When external light is incident on the head-up display device (for example, a reflection mirror) at a predetermined angle through a combiner or the like, even if a diffusion layer having a reflection directivity is laminated on the reflection mirror There is a problem that sufficient visibility cannot be ensured because the influence of external light is too great.

  The present invention has been made in view of the above-described circumstances, and its purpose is to sufficiently influence the influence of external light incident at a predetermined angle in a display device through a windshield (for example, a windshield) or a combiner. An object of the present invention is to provide a display device having sufficient visibility by reducing contrast while improving contrast, preventing image blurring, and having good brightness and viewing angle.

In order to solve the above-described problems, the display device of the present invention is
A display device that emits display light representing a display image toward a translucent member and displays the display image as a virtual image so as to be visible,
A housing disposed below the translucent member;
A light irradiation unit for irradiating the display light provided in the housing;
An anisotropic light diffusing layer disposed in the casing and having a linear transmittance that varies in accordance with an incident light angle of the display light or external light, and having a matrix region and a columnar region that is a plurality of columnar structures An anisotropic optical film comprising at least a layer;
Comprising at least
The anisotropic optical film is disposed in a part of the casing located on the display light optical path between the light irradiation unit and the light transmissive member.

  According to the present invention, while sufficiently reducing the influence of external light incident at a predetermined angle in a display device through a windshield (for example, a windshield), a combiner, etc., contrast improvement, image blur prevention, luminance and field of view are achieved. When the corner is good, a display device having sufficient visibility can be provided.

It is the schematic block diagram seen from the side of the vehicle which shows the installation state to the vehicle of the display apparatus seen from the side of the vehicle by this Embodiment (1st Embodiment), and an optical path. The structure of an anisotropic optical film (a single layer of anisotropic light diffusion layer) having a plurality of columnar structures having a pillar structure and a louver structure according to the present embodiment, and the state of transmitted light incident on these anisotropic optical films It is a schematic diagram which shows an example. It is explanatory drawing which shows the evaluation method of the light diffusivity of the anisotropic optical film (anisotropic light-diffusion layer) by this Embodiment. It is a graph which shows the relationship between the incident light angle and the linear transmittance | permeability to the anisotropic optical film (anisotropic light-diffusion layer single layer) of the pillar structure and louver structure which were shown in FIG. 2 by this Embodiment. It is a graph for demonstrating the diffusion area | region and non-diffusion area | region of the anisotropic optical film (anisotropic light-diffusion layer single layer) by this Embodiment. It is a schematic diagram which shows the structural example of the anisotropic light-diffusion layer which has the pillar structure and louver structure in the anisotropic optical film by this Embodiment, (a) is a louver structure, (b) is a pillar structure. It is a three-dimensional polar coordinate diagram for demonstrating the scattering center axis | shaft in an anisotropic light-diffusion layer. The incident light angle at which the display light irradiated from the light irradiation unit according to the present embodiment is incident on the anisotropic optical film (anisotropic light diffusion layer), and the incident light is the anisotropic optical film (anisotropic light diffusion) It is a figure explaining the relationship with the emitted light angle radiate | emitted from a layer. In FIG. 1 in the present embodiment (first embodiment), external light is diffused by an anisotropic light film (anisotropic light diffusion layer) disposed in an opening provided in a part of the housing of the HUD device. It is the schematic block diagram seen from the side of the vehicle explaining the mode. In the present embodiment (second embodiment), the polarizing member according to the first embodiment is schematically viewed from the side of a vehicle showing a configuration in which the polarizing member is provided on the surface of an anisotropic optical film (anisotropic light diffusion layer). It is a block diagram. In this embodiment (second embodiment), a vehicle showing a relationship between a polarizing member and a second polarizing plate (display light emission side polarizing plate) included in the light irradiation unit when the light irradiation unit includes a polarizing plate. It is the schematic block diagram seen from the side. In this Embodiment (3rd Embodiment), it is a schematic block diagram which shows the installation state to the vehicle of the display apparatus seen from the side of a vehicle, Comprising: An anisotropic optical film ( It is a schematic block diagram which shows the structure in which the anisotropic light-diffusion layer) was provided. In this Embodiment (4th Embodiment), it is a schematic block diagram which shows the installation state to the vehicle of the display apparatus seen from the side of a vehicle, Comprising: It is a figure which shows the structure provided with the combiner. In this Embodiment (5th Embodiment), it is a schematic block diagram which shows the installation state to the vehicle of the display apparatus seen from the vehicle side, Comprising: A reflection member is a component with respect to 1st Embodiment. It is a figure which shows the structure removed more.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that in the present specification and drawings, components having the same reference numerals have substantially the same structure or function. Further, the display device in the drawings shows only essential components of the present invention, and other components can be appropriately adjusted depending on the situation, for example, by installing them in the configuration diagram.

(First embodiment)
<< Arrangement of Display Device (Head-Up Display) 3 and Description of Virtual Image 50 and Optical Path >>
First, a head-up display device 3 (hereinafter referred to as a HUD device) as a display device according to the present embodiment will be described. The HUD device 3 is used by being mounted on a general vehicle. FIG. 1 is a schematic configuration diagram showing an installation state and an optical path of a HUD device 3 viewed from the side of the vehicle according to the first embodiment of the present invention. In the following description, in a vehicle in a stationary state, a direction along gravity is defined as a downward direction, and a direction opposite to the downward direction is defined as an upward direction.

  As shown in FIG. 1, the HUD device 3 according to the first embodiment mainly includes a light irradiation unit 31, a reflecting member 32, an anisotropic optical film 100 (anisotropic light diffusion layer), and a housing 30. As a major component.

<Optical path of virtual image 50 and display light L>
The HUD device 3 displays the display light L representing the display image irradiated from the light irradiation unit 31 on the projection area 41 of the windshield 40 via the reflection member 32 and the anisotropic optical film 100 (anisotropic light diffusion layer). Irradiate (project, project) and pass through the optical path. Then, the display image is formed on the vehicle front extension line of the line connecting the driver's eye point (viewpoint) EP and the projection area 41, and the display image is formed as a virtual image 50. As a result, the driver can visually recognize the scenery in front of the vehicle and the virtual image 50 through the windshield 40 from the driver's eye point (viewpoint) EP.

  Therefore, the driver hardly needs to move the viewpoint, and the focus adjustment of the eyes is unnecessary, so that very good visibility can be obtained. However, when the outside light such as sunlight in the morning, noon, and evening is strong, the light quantity of the virtual image 50 is smaller than the outside light, and thus the visibility may be extremely lowered.

<Windshield 40>
The windshield 40 (translucent member) is a windshield (front glass) on the front side of the vehicle. For example, a laminated glass formed of two sheets of glass and an intermediate film provided therebetween is used. . The windshield 40 has a slight curvature in the left-right direction with respect to the vehicle vertical direction and the direction along the line of the windshield 40 with respect to the side of the vehicle, and the driver's eyepoint ( (Viewpoint) From EP, the virtual image can be seen in the distance. Since the windshield 40 has translucency that allows light incident from the front of the vehicle to pass therethrough, the driver can view the scenery in front of the vehicle and the virtual image 50 at the same time. In the present embodiment, it is preferable that the windshield 40 is subjected to a process for serving as a combiner.

  FIG. 1 illustrates an example in which the projection area 41 that irradiates (projects, projects) the display light L is the windshield 40 and the driver visually recognizes the display light L reflected by the windshield 40. Instead of the shield 40, a translucent member having translucency (for example, a combiner or an anisotropic optical film) may be used (a specific embodiment will be described later).

<Display image>
As a display image irradiated from the light irradiation part 31, it can be set as the map information in a vehicle navigation system, the present position information of the own vehicle on a map, or the guidance information to a destination etc., for example. Moreover, as a display image, it is good also as information, such as a vehicle speed, an engine speed, an engine cooling water temperature, and a battery voltage, as vehicle information at the time of vehicle travel.

<Example of arrangement of HUD device 3>
As shown in FIG. 1, the HUD device 3 is housed inside an instrument panel 42 in the downward direction of the windshield 40. The HUD device 3 includes a housing 30 and an opening 33 provided in a part of the housing 30, and a display image is displayed from the opening 33 toward the windshield 40 outside the instrument panel 42. The display light L can be irradiated. The instrument panel 42 is provided with, for example, an opening window having the same size as the opening 33 in order to allow the display light L to pass through the windshield 40.
The opening 33 or the opening window may be provided with a transparent cover (dust-proof cover) made of glass or the like, for example, in order to prevent dust and dirt from entering the HUD device 3.

  The HUD device 3 has a housing 30 provided in a downward direction of the windshield 40 of the vehicle, and a light irradiation unit 31 and a reflecting member 32 are provided in the housing 30. An anisotropic optical film 100 (anisotropic light diffusion layer) is disposed in an opening 33 provided in a part of the housing 30.

<Light irradiation unit 31>
The light irradiation unit 31 is a member that irradiates display light L representing a display image. For example, a video projection device. Specifically, the video projection apparatus is configured by, for example, a projector (not shown), a liquid crystal display with a backlight, or the like.

  The backlight uses, for example, an LED light source as a light source. The backlight irradiates light along the optical axis with respect to the liquid crystal display. The liquid crystal display has a function as a display that emits display light L representing a display image.

  The liquid crystal display irradiates the display image formed on the surface with the light emitted from the backlight as the display light L toward the reflecting member 32 on the opposite side of the backlight. The surface on which the display light L of the liquid crystal display is irradiated faces, for example, the vertical direction in FIG. 1 (perpendicular to the vehicle front-rear direction in FIG. 1), and the optical axis of the display light extends in the vehicle front-rear direction. It arrange | positions so that it may face (irradiation direction faces the front side of a vehicle).

  The light irradiation unit 31 is not only a liquid crystal display but also an LCoS method using a reflective liquid crystal panel, a DLP method that scans light emitted from an LED with a micromirror to generate a display image, or irradiation from a laser light source. A laser system that scans the generated light to generate a display image may be used.

<Reflection member 32>
The reflection member 32 is a member that changes the optical path by reflecting the display light L representing the display image from the light irradiation unit 31 toward the projection area 41 of the windshield 40 through the opening 33.

  The reflection member 32 is, for example, an ordinary mirror that simply reflects the display light L by depositing a metal (eg, aluminum) on a resin (eg, polycarbonate, glass, polyester, etc.) to form a reflection surface. is there.

  The reflecting member 32 may be an aspherical mirror (for example, a concave mirror) that reflects the display light L and magnifies a virtual image. The reflecting member 32 is fixed at a predetermined position inside the housing 30 and is detachable from the housing 30.

  Note that the number and type of the reflection members 32 are not limited to the above-described configuration, and the number and type of reflection members 32 appropriately adjusted according to the application can be used. For example, not only one reflecting member 32 but also two reflecting mirrors for changing the optical path of the display light L from the light irradiation unit 31 and a concave mirror for expanding the display light L reflected by the reflecting mirror. It may be configured.

  Further, the reflecting member 32 may be composed of two aspherical mirrors (a first aspherical mirror and a second aspherical mirror). In this case, the first aspherical mirror reflects the display light L from the light irradiation unit 31 toward the second aspherical mirror, and the second aspherical mirror reflects the display light L from the first aspherical mirror in the windshield 40. Reflect towards The first aspherical mirror and the second aspherical mirror have an optical path changing action and a virtual image enlarging action of display light.

<Anisotropic optical film 100 (anisotropic light diffusion layer)>
The housing 30 has an anisotropic optical film (anisotropic light diffusion) whose linear transmittance changes depending on the incident light angle of display light or external light incident on the reflecting surface side of the reflecting member 32, that is, the incident light angle dependency. Layer) 100 is provided.

  Specifically, as shown in FIG. 1, the light irradiation unit is provided between a reflection member 32 provided inside the housing 30 and a windshield 40 (translucent member) outside the housing 30. The display light L emitted from 31 is reflected by the reflecting member 32 and is on the optical path of the display light L toward the windshield 40 (translucent member) through the opening 33. Alternatively, from another viewpoint, as shown in FIG. 9 to be described later, between the reflecting member 32 provided inside the housing 30 and the windshield 40 (translucent member) outside the housing 30. In addition, the external light M such as sunlight passes through the windshield 40 (translucent member) and is on the optical path of the external light M that goes to the inside of the housing 30 through the opening 33.

  More specifically, the anisotropic optical film 100 (anisotropic light diffusion layer) can be said to be a part of the housing 30 and is provided so as to close the opening 33 of the housing 30, for example. Here, a part of the housing 30 indicates an area of an opening formed on one surface constituting the housing 30, for example, half of one surface constituting the housing 30 or one whole surface. Is formed as a part of the case. Further, the installation of the anisotropic optical film 100 (anisotropic light diffusion layer) is not limited to the above-described configuration. For example, the anisotropic optical film 100 is anisotropic at a position (place) corresponding to the opening 33 of the housing 30. The structure which provides the optical film 100 (anisotropic light diffusion layer), ie, the structure which forms the housing | casing 30 and the anisotropic optical film 100 (anisotropic light diffusion layer) integrally, may be sufficient.

  The anisotropic optical film 100 (anisotropic light diffusion layer) will be described in detail below.

<<< Definition of main terms >>>
Here, with respect to the anisotropic optical film 100 (anisotropic light diffusion layer), main terms are defined.
“Anisotropic optical film” means that when the anisotropic light diffusion layer is a single layer (only one layer), the anisotropic light diffusion layer is formed by laminating two or more layers (in this case, the anisotropic light diffusion layer is an adhesive layer). Or the like may be laminated via, etc.). Therefore, for example, when the anisotropic light diffusion layer is a single layer, it means that the single anisotropic light diffusion layer is an anisotropic optical film.
The “anisotropic light diffusion layer” has anisotropy and directivity in which the diffusion, transmission, and diffusion distribution of light change depending on the incident angle of light that changes depending on the incident angle of light (details will be described later). Therefore, it is different from a directional diffusion film having no incident light angle dependency, an isotropic diffusion film, and a diffusion film oriented in a specific direction.
The “low refractive index region” and the “high refractive index region” are regions formed by the difference in local refractive index of the material constituting the anisotropic optical film according to the present invention, compared to the other. It is a relative value indicating whether the refractive index is low or high. These regions are formed when the material forming the anisotropic optical film is cured.

  The “scattering center axis” is a direction in which the light diffusibility coincides with the incident light angle of light having a substantially symmetrical shape with respect to the incident light angle when the incident light angle to the anisotropic optical film is changed. means. “Having substantially symmetry” means that when the scattering central axis is inclined with respect to the normal direction of the film (film thickness direction), an optical profile related to light diffusivity (an optical profile described later) This is because there is strictly no symmetry. The scattering center axis should be confirmed by observing the inclination of the cross section of the anisotropic optical film with an optical microscope or by observing the projected shape of light through the anisotropic optical film while changing the incident light angle. Can do.

In addition, “linear transmittance” generally relates to the linear transmittance of light incident on the anisotropic optical film, and the light incident on the anisotropic optical film from a certain incident light angle. The ratio between the transmitted light amount in a straight line direction (linear transmitted light amount) and the light amount of incident light is expressed by the following equation.
Linear transmittance (%) = (Linear transmitted light amount / incident light amount) × 100

  In the present invention, both “scattering” and “diffusion” are used without distinction, and both indicate the same meaning. Furthermore, the meaning of “photopolymerization” and “photocuring” means that a photopolymerizable compound undergoes a polymerization reaction with light, and both are used synonymously.

<<< Structure and Properties of Anisotropic Optical Film >>>
2 to 5, the structure and characteristics of a single-layer anisotropic optical film according to this embodiment (an anisotropic optical film in the case where there is only one “anisotropic light diffusion layer” in this embodiment) Will be described.

  FIG. 2 shows the structure of an anisotropic optical film having a plurality of columnar structures (columnar regions) having a pillar structure and a louver structure, and transmitted light incident on these anisotropic optical films. It is a schematic diagram which shows an example of the mode. FIG. 3 is an explanatory view showing a method for evaluating light diffusibility of an anisotropic optical film (anisotropic light diffusion layer). FIG. 4 is a graph showing the relationship between the incident light angle and the linear transmittance on the anisotropic optical film (anisotropic light diffusion layer single layer) having the pillar structure and the louver structure shown in FIG. FIG. 5 is a graph for explaining a diffusion region and a non-diffusion region of an anisotropic optical film (anisotropic light diffusion layer single layer).

<< Basic structure of anisotropic light diffusion layer >>
The anisotropic light diffusion layer is a layer in which a region having a refractive index different from that of the matrix region of the film is formed in the film thickness direction. The shape of the regions having different refractive indexes is not particularly limited. For example, as shown in FIG. 2A, the matrix region 11 has a columnar shape (for example, a rod shape) with a minor axis and a minor axis having a small aspect ratio. 2) formed with a plurality of columnar structures 13 (columnar regions) having different refractive indexes, or a matrix as shown in FIG. 2B. Anisotropic light diffusion layer (an anisotropic light diffusion having a louver structure) in which a plurality of columnar structures 23 (columnar regions) having different refractive indexes formed in a columnar shape (for example, substantially plate shape) having a large aspect ratio are formed in the region 21 Layer) 20 and so on.

<< Characteristics of Anisotropic Optical Film >>
The anisotropic optical film having the above-described structure is a light diffusing film having different light diffusibility depending on an incident light angle to the film, that is, having an incident light angle dependency. The light incident on the anisotropic optical film at a predetermined incident light angle is directed to the orientation direction of the regions having different refractive indexes (for example, the extending direction of the plurality of columnar structures 13 in the pillar structure (the film of the anisotropic optical film). Thickness direction or normal direction) or the height direction of the plurality of columnar structures 23 in the louver structure (thickness direction or normal direction of the anisotropic optical film)) is substantially parallel to diffusion. If transmission is not parallel to the direction, transmission is given priority.

  Here, the light diffusibility of the anisotropic optical film will be described more specifically with reference to FIGS. Here, the light diffusibility of the anisotropic light diffusion layer 10 having the pillar structure and the anisotropic light diffusion layer 20 having the louver structure will be described as an example.

  The light diffusivity is evaluated by measuring linear transmittance as follows. First, as shown in FIG. 3, a sample (in this case, the anisotropic light diffusion layer 10 or 20 or an anisotropic optical film) may be disposed between the light source 1 and the detector 2. In the present embodiment, the incident light angle 0 is set when the irradiation light I from the light source 1 is incident from the plane normal direction (film thickness direction) of the samples 10 and 20. Further, the samples 10 and 20 are arranged so that they can be arbitrarily rotated around the straight line V on the sample surface, and the light source 1 and the detector 2 are fixed. That is, according to this method, the samples 10 and 20 are arranged between the light source 1 and the detector 2, and the samples 10 and 20 are transmitted in a straight line (incident) while changing the sample angle about the straight line V of the sample surface as the central axis. The linear transmittance can be measured from the amount of light entering the detector 2 (parallel to the light) (linear transmitted light amount).

  The anisotropic light diffusing layers 10 and 20 are each evaluated for light diffusibility when the axis in the TD direction (width direction of the anisotropic light diffusing layer) in FIG. 2 is selected as the straight line V of the rotation center shown in FIG. The obtained light diffusibility evaluation results are shown in FIG. 4 shows the incident light angle dependency of the light diffusivity (light scattering property) of the anisotropic optical films (anisotropic light diffusion layer single layers) 10 and 20 shown in FIG. 2 measured using the method shown in FIG. Is shown. The vertical axis in FIG. 4 indicates the linear transmittance that is an index indicating the degree of scattering (in this embodiment, when a parallel light beam having a predetermined light amount is incident, the light amount of the parallel light beam emitted in the same direction as the incident direction is shown. Ratio, more specifically, linear transmittance = (detected light amount of the detector when there is an anisotropic optical film (transmitted light amount of incident light in the linear direction) / detector when there is no anisotropic optical film) , The horizontal axis indicates the angle of incident light on the anisotropic optical film, and the solid line in Fig. 4 indicates the light diffusion of the anisotropic light diffusion layer 10 having a pillar structure. The broken line shows the light diffusibility of the anisotropic light diffusion layer 20 having the louver structure, and the positive / negative of the incident light angle indicates that the direction in which the anisotropic light diffusion layers 10 and 20 are rotated is opposite. Show.

  As shown in FIG. 4, the anisotropic optical films (anisotropic light diffusion layers) 10, 20 have light diffusivity in which the linear transmittance changes depending on the incident light angle. Here, as shown in FIG. 4, the curve indicating the dependence of the light diffusivity on the incident light angle is hereinafter referred to as an “optical profile”. The optical profile does not directly express the light diffusivity, but if it is interpreted that the diffuse transmittance is increased (increased) due to the decrease of the linear transmittance, the light diffusivity is almost the same. It can be said that it shows. In other words, the diffuse transmittance of incident light increases as the linear transmittance decreases. A normal isotropic light diffusion film shows an optical profile with a substantially constant linear transmittance peaking at around 0 °, but the anisotropic optical films (anisotropic light diffusion layers) 10 and 20 have a plurality of optical profiles. Compared to the linear transmittance in the case of incidence in the central axis direction of the columnar structures 13 and 23, that is, the scattering central axis direction (the incident light angle in this direction is 0 °), −20 ° to + 20 ° The linear transmittance once becomes the minimum value at the incident light angle of, and as the incident light angle (the absolute value thereof) increases, the linear transmittance increases, and the incident angle is -60 ° to -30 ° or + 30 ° to + 60 °. The valley-shaped optical profile in which the linear transmittance becomes the maximum value at the light angle is shown. As described above, in the anisotropic optical films (anisotropic light diffusion layers) 10 and 20, the incident light is strongly diffused in the incident light angle range of −20 ° to + 20 ° close to the scattering center axis direction. In the incident light angle range (specifically −60 ° to −30 ° or + 30 ° to + 60 °) where the absolute value of is larger than that, the diffusion is weakened and the linear transmittance is increased.

  Here, as shown in FIG. 4, the property (optical profile) in which diffusivity increases (increases) with respect to light (display light or external light) incident in a predetermined angle range and the linear transmittance has a minimum value. That is, in the predetermined angle range, the light has a property (optical profile) in which the diffusion of light is prioritized. Further, as shown in FIG. 4, light incident at an angle other than the predetermined angle range (display light) Alternatively, it has a property (optical profile) in which diffusivity is reduced and the linear transmittance is maximum with respect to outside light (optical profile). Such a property is called “anisotropic”. That is, it means that the diffusion and transmission of light change depending on the incident light angle of light. As described above, the predetermined angle range in which light diffusion is given priority is compared with the linear transmittance when the light is incident in the scattering central axis direction (the incident light angle in this direction is 0 °). For example, it refers to a range of incident light angles of −20 ° to + 20 °. Further, as described above, the linear transmittance in the case where the light is incident in the scattering central axis direction (the incident light angle in this direction is assumed to be 0 °) is other than the predetermined angle range in which light transmission is prioritized. In comparison, for example, it refers to a range of incident light angles of −60 ° to −30 ° or + 30 ° to + 60 °.

  In addition, in the present invention, the light diffusion distribution differs depending on the diffusion angle but also changes depending on the incident light angle. The diffusion distribution further having the light angle dependency is shown. That is, the diffusion, transmission, and diffusion distribution of light have anisotropy and directivity having incident light angle dependency that varies depending on the incident angle of light.

  Further, hereinafter, the angle range of two incident light angles with respect to the linear transmittance that is an intermediate value between the maximum linear transmittance and the minimum linear transmittance is referred to as a diffusion region (the width of the diffusion region is referred to as a “diffusion width”), and otherwise. The incident light angle range is referred to as a non-diffusion region (transmission region).

  Here, with reference to FIG. 5, the diffusion region and the non-diffusion region will be described by taking the anisotropic light diffusion layer 20 having a louver structure as an example. FIG. 5 shows an optical profile of the anisotropic optical film (anisotropic light diffusing layer single layer) 20 having the louver structure of FIG. 4. As shown in FIG. 5, the maximum linear transmittance (of FIG. 5) is shown. In the example, the linear transmittance (in the example of FIG. 5, the linear transmittance is about 78%) and the minimum linear transmittance (in the example of FIG. 5, the linear transmittance is about 6%). The incident light angle range between the two incident light angles with respect to (about 42%) (inside the two incident light angles at the positions of the two black spots on the optical profile shown in FIG. 5) is the diffusion region, and the others (FIG. 5 The incident light angle range outside the two incident light angles at the positions of the two black spots on the optical profile shown in FIG.

  In the anisotropic light diffusion layer 10 having the pillar structure, as can be seen from the state of the transmitted light in FIG. 2A, the transmitted light has a substantially circular shape, and substantially the same light diffusion in the MD direction and the TD direction. Showing sex. That is, in the anisotropic light diffusion layer 10 having a pillar structure, the diffusion is isotropic when viewed in the azimuth direction. In addition, as shown by the solid line in FIG. 4, since the change in light diffusivity (particularly the optical profile near the boundary between the non-diffusing region and the diffusing region) is relatively gradual even when the incident light angle is changed, There is an effect of not causing a sense of incongruity due to a sudden change. However, the anisotropic diffusion layer 10 has a low linear transmittance in the non-diffusion region, as can be understood by comparing with the optical profile of the anisotropic light diffusion layer 20 having the louver structure shown by the broken line in FIG. There is also a problem that characteristics (luminance, contrast, etc.) are slightly lowered. Further, the anisotropic light diffusion layer 10 having a pillar structure has a problem that the width of the diffusion region is narrower than that of the anisotropic light diffusion layer 20 having a louver structure. The pillar structure has no directivity of diffusion due to the azimuth, but has a directivity with respect to the distribution of diffusion.

  On the other hand, in the anisotropic light diffusion layer 20 having the louver structure, as can be seen from the state of the transmitted light in FIG. 2B, the transmitted light has a substantially needle shape and is diffused in the MD direction and the TD direction. Sex is very different. That is, in the anisotropic light diffusing layer 20 having the louver structure, the diffusion has a directivity having a large diffusion characteristic depending on the azimuth angle. Specifically, in the example shown in FIG. 2B, diffusion is wider in the MD direction than in the case of the pillar structure, but diffusion is narrower in the TD direction than in the case of the pillar structure. Further, as shown by a broken line in FIG. 4, when the incident light angle is changed (in the case of this embodiment, in the TD direction), the light diffusibility (in particular, the optical profile near the boundary between the non-diffusing region and the diffusing region) changes. Therefore, when the anisotropic light diffusing layer 20 is applied to a display device, there is a possibility that a sudden change in luminance appears and an uncomfortable feeling may occur. In addition, the anisotropic light diffusion layer having a louver structure has a problem that light interference (rainbow) is likely to occur. However, the anisotropic light diffusion layer 20 has an effect that the linear transmittance in the non-diffusion region is high and display characteristics can be improved. In particular, by matching the viewing angle of the preferred diffusion direction (MD direction in FIG. 2B) with the direction in which the viewing angle is desired to be widened, the viewing angle can be widened in the intended specific direction.

<<< Configuration of Anisotropic Optical Film According to this Embodiment >>>
The structure of the anisotropic optical film 100 according to this embodiment will be described with reference to FIG. FIG. 6 is a diagram showing an example of the configuration of the anisotropic light diffusion layers 110 and 120 in the anisotropic optical film 100 according to this embodiment. In the following, when the anisotropic optical film 100 is used, an anisotropic light diffusion layer having each single layer of the anisotropic light diffusion layer 110 or 120 may be simply indicated.

<< Overall structure >>
As shown in FIG. 6, the anisotropic optical film 100 is an anisotropic optical film having at least an anisotropic light diffusion layer 110 or 120 whose linear transmittance changes according to the incident light angle.

  The anisotropic light diffusion layer 110 includes a matrix region 111 and a plurality of columnar structures 113 (columnar regions) having a refractive index different from that of the matrix region 111. The anisotropic light diffusion layer 120 includes a matrix region 121 and a plurality of columnar structures 123 (columnar regions) having different refractive indexes from the matrix region 121. Here, when it is simply expressed as a columnar region, the columnar region includes one of the pillar region and the louver region, or both. In addition, when the term “columnar structure” is simply used, the columnar structure includes either or both of the pillar structure and the louver structure.

  Here, the aspect ratio of the average minor axis to the average major axis (= average major axis / average minor axis) on the surface of the anisotropic light diffusion layer 110 or 120 (or a cross section perpendicular to the orientation direction) of the plurality of columnar structures 113 and 123. ) Are preferably different. More specifically, the anisotropic optical film according to the present invention has either or both of the above-described pillar structure and louver structure inside the anisotropic light diffusion layer in a preferred embodiment.

  Hereinafter, the anisotropic optical film 100 having the anisotropic light diffusion layers 110 and 120 will be described in detail.

<< anisotropic light diffusion layer 110 >>
The anisotropic light diffusing layer 110 has the above-described louver structure (the same configuration as the anisotropic light diffusing layer 20 in FIG. 2B), and has a light diffusibility in which the linear transmittance varies depending on the incident light angle. ing. The anisotropic light diffusion layer 110 is formed of a cured product of a composition containing a photopolymerizable compound. As shown in FIG. 6A, the matrix region 111 and a plurality of columnar structures having different refractive indexes from the matrix region 111 are used. 113 (columnar region). The orientation direction (extending direction) P of the columnar structure 113 is formed so as to be parallel to the scattering center axis, and is determined appropriately so that the anisotropic light diffusion layer 110 has desired linear transmittance and diffusibility. It has been. It should be noted that the fact that the scattering central axis and the alignment direction of the columnar region are parallel only needs to satisfy the law of refractive index (Snell's law), and does not need to be strictly parallel. Snell's law, when the light to the interface of the medium refractive index _{n 2} from a medium of refractive index _{n 1} is incident, between the incident light angle theta ₁ and refraction angle θ _2, n ₁ sinθ 1 = The relationship of n ₂ sin θ ₂ is established. For example, when n ₁ = 1 (air) and n ₂ = 1.51 (anisotropic optical film), when the incident light angle is 30 °, the orientation direction (refractive angle) of the columnar structure is about 19 °. However, even if the incident light angle and the refraction angle are different from each other as long as Snell's law is satisfied, the present embodiment includes the parallel concept.

  In addition, as the anisotropic light-diffusion layer 110, the orientation direction of the columnar structure 113 may not match the film thickness direction (normal direction) of the film. In this case, in the anisotropic light diffusion layer 110, the incident light angle range (diffusion region) close to the direction in which the incident light is inclined at a predetermined angle from the normal direction of the anisotropic light diffusion layer 110 (that is, the orientation direction of the columnar structure 113). However, in the incident light angle range (non-diffusion region) beyond that, the diffusion is weakened and the linear transmittance is increased.

<Columnar structure 113>
The columnar structure 113 according to this embodiment is provided as a plurality of columnar hardened regions in the matrix region 111, and each columnar structure 113 is formed so that the alignment direction is parallel to the scattering center axis. It has been done. Accordingly, the plurality of columnar structures 113 in the same anisotropic light diffusion layer 110 are formed to be parallel to each other.

  The refractive index of the matrix region 111 may be different from the refractive index of the columnar structure 113, but how much the refractive index is different is not particularly limited and is a relative one. When the refractive index of the matrix region 111 is lower than the refractive index of the columnar structure 113, the matrix region 111 becomes a low refractive index region. Conversely, when the refractive index of the matrix region 111 is higher than the refractive index of the columnar structure 113, the matrix region 111 becomes a high refractive index region. Here, it is preferable that the refractive index at the interface between the matrix region 111 and the columnar structure 113 changes gradually. By changing the angle gradually, the change in diffusibility when the incident light angle is changed becomes extremely steep, and the problem that glare is likely to occur is less likely to occur. By forming the matrix region 111 and the columnar structure 113 by phase separation accompanying light irradiation, the refractive index of the interface between the matrix region 111 and the columnar structure 113 can be gradually increased.

  The cross-sectional shape perpendicular to the alignment direction of the columnar structure 113 has a short diameter SA and a long diameter LA as shown in FIG. 6A. The short diameter SA and the long diameter LA can be confirmed by observing the anisotropic light diffusion layer 110 with an optical microscope (details will be described later). The cross-sectional shape of the columnar structure 113 preferably satisfies an aspect ratio range (2 or more) described later. For example, in FIG. 6A, the cross-sectional shape of the columnar structure 113 is shown as an elliptical shape, but the cross-sectional shape of the columnar structure 113 is not particularly limited.

<< anisotropic light diffusion layer 120 >>
The anisotropic light diffusing layer 120 has a pillar structure (similar structure to the anisotropic light diffusing layer 10 in FIG. 2A), and has a light diffusibility in which the linear transmittance varies depending on the incident light angle. . Further, as shown in FIG. 6B, the anisotropic light diffusion layer 120 is made of a cured product of a composition containing a photopolymerizable compound, and a matrix region 121 and a plurality of columnar structures having different refractive indexes from the matrix region 121. 123 (columnar region). The plurality of columnar structures 123 and the matrix regions 121 have an irregular distribution and shape, but optical characteristics (for example, linear transmittance) obtained by being formed over the entire surface of the anisotropic light diffusion layer 120 are substantially the same. It will be the same. Since the plurality of columnar structures 123 and the matrix region 121 have an irregular distribution or shape, the anisotropic light diffusion layer 120 according to this embodiment is less likely to cause light interference (rainbow).

<Columnar structure 123>
The columnar structure 123 according to this embodiment is provided as a plurality of columnar hardened regions in the matrix region 121, and each columnar structure 123 is formed so that the alignment direction is parallel to the scattering center axis. It has been done. Therefore, the plurality of columnar structures 123 in the same anisotropic light diffusion layer 120 are formed to be parallel to each other.

  Although the refractive index of the matrix area | region 121 should just differ from the refractive index of the columnar structure 123, how much a refractive index differs is not specifically limited, It is a relative thing. When the refractive index of the matrix region 121 is lower than the refractive index of the columnar structure 123, the matrix region 121 becomes a low refractive index region. Conversely, when the refractive index of the matrix region 121 is higher than the refractive index of the columnar structure 123, the matrix region 121 becomes a high refractive index region.

  The cross-sectional shape perpendicular to the alignment direction of the columnar structure 123 has a short diameter SA and a long diameter LA as shown in FIG. 6B. The short diameter SA and the long diameter LA can be confirmed by observing the anisotropic light diffusion layer 110 with an optical microscope (details will be described later). The cross-sectional shape of the columnar structure 123 preferably satisfies an aspect ratio range (less than 2) described later. For example, in FIG. 6B, the cross-sectional shape of the columnar structure 123 is shown in a circular shape, but the cross-sectional shape of the columnar structure 123 is not limited to a circular shape, but an elliptical shape, a polygonal shape, an indefinite shape, There are no particular limitations on such a mixture.

<< Shape of columnar structure >>
<Aspect ratio of columnar structures 113 and 123>
The plurality of columnar structures 113 preferably have an aspect ratio (= average major axis / average minor axis) of an average value of the minor axis SA (average minor axis) and an average value of the major axis LA (average major axis) of 2 or more. It is more preferably 2 or more and less than 50, further preferably 2 to 10, and particularly preferably 2 to 5.

  The plurality of columnar structures 123 preferably have an aspect ratio (= average major axis / average minor axis) of an average value of the minor axis SA (average minor axis) and an average value (average major axis) of the average major axis LA of less than 2. , Less than 1.5, more preferably less than 1.2.

  The anisotropic optical film 100 according to the present embodiment balances various characteristics at a higher level by setting both the average minor axis and the average major axis aspect ratio of the plurality of columnar structures 113 and 123 within the above-described preferable range. It can be set as the anisotropic optical film which has well.

<Average minor axis and average major axis of columnar structures 113 and 123>
In addition, the average value of the minor axis SA (average minor axis) of the plurality of columnar structures 113 is preferably 0.5 μm or more, more preferably 1.0 μm or more, and 1.5 μm or more. Further preferred. On the other hand, the average value (average minor axis) of the minor axis SA of the plurality of columnar structures 113 is preferably 5.0 μm or less, more preferably 4.0 μm or less, and 3.0 μm or less. Further preferred. The lower limit value and the upper limit value of the average minor axis of the plurality of columnar structures 113 can be appropriately combined.

  Furthermore, the average value (average major axis) of the major axis LA of the plurality of columnar structures 113 is preferably 0.5 μm or more, more preferably 1.0 μm or more, and further preferably 1.5 μm or more. . On the other hand, the average value (average major axis) of the major axis LA of the plurality of columnar structures 113 is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The lower limit value and the upper limit value of the average major axis of the plurality of columnar structures 113 can be appropriately combined.

  The average value (average minor axis) of the minor axis SA of the plurality of columnar structures 123 is preferably 0.5 μm or more, more preferably 1.0 μm or more, and 1.5 μm or more. Further preferred. On the other hand, the average value (average minor axis) of the minor axis SA of the plurality of columnar structures 123 is preferably 5.0 μm or less, more preferably 4.0 μm or less, and 3.0 μm or less. Further preferred. The lower limit value and upper limit value of the average minor axis of the plurality of columnar structures 123 can be appropriately combined.

  Furthermore, the average value (average major axis) of the major axis LA of the plurality of columnar structures 123 is preferably 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.5 μm or more. . On the other hand, the average value (average major axis) of the major axis LA of the plurality of columnar structures 123 is preferably 8.0 μm or less, more preferably 5.0 μm or less, and even more preferably 3.0 μm or less. . The lower limit value and upper limit value of the average major axis of the plurality of columnar structures 123 can be appropriately combined.

  The anisotropic optical film 100 according to the present embodiment has a different level of balance between various characteristics at a higher level by setting both the average minor axis and the average major axis of the plurality of columnar structures 113 and 123 within the above-described preferable ranges. It can be set as an isotropic optical film.

  In addition, the average value of the minor axis SA (average minor axis) and the average value of the major axis LA (average major axis) of the plurality of columnar structures 113 and 123 in the present embodiment are measured on the surfaces of the anisotropic light diffusion layers 110 and 120 with a microscope. What is necessary is just to measure the short diameter SA and the long diameter LA of 100 columnar structures 113 and 123 that are observed and arbitrarily selected, and obtain an average value thereof. Further, as the aspect ratio of the columnar structure, a value obtained by dividing the average value (average major axis) of the major axis LA obtained above by the average value (average minor axis) of the minor axis SA is used.

<Thickness of region where columnar structures 113 and 123 are formed>
The thickness T of the plurality of columnar structures 113 and 123 is preferably 10 μm to 200 μm, more preferably 20 μm or more and less than 100 μm, and still more preferably 20 μm or more and less than 50 μm. When the thickness T exceeds 200 μm, not only the material cost is increased, but also the cost for UV irradiation is increased, so that not only the cost is increased, but also an increase in diffusibility in the thickness T direction causes an image blur and a decrease in contrast. It tends to happen. Further, when the thickness T is less than 10 μm, it may be difficult to achieve sufficient light diffusibility and light condensing performance. In the present invention, by setting the thickness T within the specified range, the problem of cost is reduced, the light diffusibility and the light condensing property are excellent, and the light diffusibility is decreased in the thickness T direction, thereby reducing the image. Blur is less likely to occur and the contrast can be improved.

<< Properties of Anisotropic Optical Film 100 >>
As described above, the anisotropic optical film 100 has either or both of the anisotropic light diffusion layers 110 and 120. More specifically, the anisotropic light diffusion layer 110 has a louver structure (preferably a structure having a plurality of columnar structures having an aspect ratio of 2 or more). The anisotropic light diffusion layer 120 has a pillar structure (preferably a structure having a plurality of columnar structures having an aspect ratio of less than 2). Hereinafter, the properties of the anisotropic optical film 100 will be described.

<Linear transmittance>
Here, if the linear transmittance of light incident on the anisotropic optical film 100 (the anisotropic light diffusion layers 110 and 120) at the incident light angle at which the linear transmittance is the maximum is defined as “maximum linear transmittance”, it is anisotropic. The optical optical film 100 (anisotropic light diffusing layers 110 and 120) preferably has a maximum linear transmittance of 20% or more, more preferably 30% or more, still more preferably 50% or more, 70 % Or more is particularly preferable, and it is particularly preferable that it is less than 90%.

  If the linear transmittance of light incident on the anisotropic optical film 100 (the anisotropic light diffusion layers 110 and 120) at the incident light angle at which the linear transmittance is minimum is defined as “minimum linear transmittance”, anisotropy is obtained. The optical film 100 (anisotropic light diffusion layers 110, 120) preferably has a minimum linear transmittance of 10% or less.

  By setting the maximum linear transmittance of the anisotropic optical film 100 (anisotropic light diffusion layers 110 and 120) within the above range, the anisotropic optical film 100 (anisotropic light) can be obtained. The application range of the diffusion layers 110, 120) can be widened. For example, when an anisotropic optical film is used for a display device, if the anisotropy is too strong, the light diffusion / condensation property in the MD direction is extremely excellent, but the light diffusion / condensation property in the TD direction is excellent. May be insufficient. The anisotropic optical film 100 (anisotropic light diffusing layers 110 and 120) according to this embodiment has the above-described maximum linear transmittance and minimum linear transmittance, so that it has excellent light diffusion and condensing properties in the MD direction. In addition, the light has sufficient diffusion and condensing properties in the TD direction.

  Here, the linear transmitted light amount and the linear transmittance can be measured by the method shown in FIG. That is, the linear transmitted light amount and the linear transmittance at each incident light angle are measured so that the rotation center straight line V shown in FIG. 3 and the CC axis shown in FIGS. 6A and 6B coincide (film thickness direction). That is, the normal direction is set to 0 °). An optical profile is obtained from the obtained data, and the maximum linear transmittance and the minimum linear transmittance can be obtained from the optical profile.

  Moreover, the maximum linear transmittance and the minimum linear transmittance in the anisotropic optical film 100 (the anisotropic light diffusion layers 110 and 120) can be adjusted by design parameters at the time of manufacture. Examples of the parameters include the composition of the coating film, the film thickness of the coating film, the temperature to the coating film given during structure formation, and the like. The composition of the coating film changes the maximum linear transmittance and the minimum linear transmittance by appropriately selecting and preparing the constituent components. In the design parameter, the maximum linear transmittance and the minimum linear transmittance tend to be lower as the film thickness is thicker, and higher as the film thickness is thinner. Further, the maximum linear transmittance and the minimum linear transmittance are likely to be lower as the temperature is higher, and higher as the temperature is lower. Each of the maximum linear transmittance and the minimum linear transmittance can be appropriately adjusted by a combination of these parameters.

<Diffusion width>
The maximum linear transmittance and the minimum linear transmittance of the anisotropic optical film 100 (anisotropic light diffusion layers 110 and 120) are obtained by the above-described method, and the linear transmittance is an intermediate value between the maximum linear transmittance and the minimum linear transmittance. Ask for. Subsequently, the intersection of two incident light angles with respect to the linear transmittance of the intermediate value is read. In the optical profile, the normal direction of the anisotropic optical film is 0 °, and the incident light angle is shown in the minus direction and the plus direction. Accordingly, the incident light angle and the incident light angle corresponding to the two intersections described above may have negative values. If the value of the intersection of the above two incident light angles has a positive incident light angle value and a negative incident light angle value, the absolute value of the negative incident light angle value and the positive incident light angle value The sum is the diffusion width that is the angular range of the diffusion region of the incident light. When the values of the intersections of the two incident light angles described above are both positive, the difference obtained by subtracting the smaller value from the larger value is the diffusion width. When the values of the intersections of the two incident light angles described above are both negative, the absolute value of each is taken, and the difference obtained by subtracting the smaller value from the larger value is the diffusion width.

  In the anisotropic optical film 100 (anisotropic light diffusing layers 110 and 120), the angle range of the incident light angle corresponding to two intersections with respect to the linear transmittance of the intermediate value between the maximum linear transmittance and the minimum linear transmittance. The width of the diffusion region (diffusion width) is preferably 10 ° or more and less than 70 °, and more preferably 30 ° or more and less than 50 ° in the MD direction. Further, in the TD direction, it is preferably 5 ° or more and less than 50 °, and more preferably 20 ° or more and less than 30 °. When it is out of the specified range, that is, when the diffusion width becomes too wide, the light condensing property is weakened. When the diffusion width is too narrow, the display property and visibility are lowered due to the weakening of the diffusivity. Resulting in. That is, according to the present invention, since the diffusion width is within the specified range, it is possible to balance the diffusibility and the light condensing property, and to further enhance the effect of suppressing a rapid change in luminance.

<Scattering central axis>
Next, the scattering center axis P in the anisotropic light diffusion layer will be described with reference to FIG. FIG. 7 is a three-dimensional polar coordinate diagram for explaining the scattering center axis P in the anisotropic light diffusion layer.

  The anisotropic light diffusing layer has at least one scattering central axis. As described above, the scattering central axis has a light diffusibility when the incident light angle to the anisotropic light diffusing layer is changed. Means a direction coinciding with the incident light angle of light having substantially symmetry with respect to. The scattering center axis angle, which is the incident light angle at this time, creates an optical profile that is a curve indicating the incident light angle dependency of the light diffusivity of the anisotropic light diffusing layer, and is sandwiched between the minimum values in this optical profile. It becomes a substantially central portion (central portion of the diffusion region).

  Further, according to the three-dimensional polar coordinate diagram as shown in FIG. 7, the above-mentioned scattering center axis is the normal direction (film thickness direction) with the flat surface in the plane direction (surface direction) of the anisotropic light diffusion layer as the xy plane. Can be expressed by a polar angle θ and an azimuth angle φ (P). That is, Pxy in FIG. 7 can be said to be the length direction of the scattering central axis projected on the surface of the anisotropic light diffusion layer.

  Here, the anisotropic light diffusion layer 110 has a plurality of columnar structures 113, and the anisotropic light diffusion layer 120 has a plurality of columnar structures 123. Polar angle θ (−) formed between the normal line of anisotropic light diffusion layers 110 and 120 (thickness direction of anisotropic light diffusion layer, z-axis shown in FIG. 7) and columnar structure 113 or columnar structure 123 corresponding thereto. 90 ° <θ <90 °) is defined as a scattering center axis angle (an angle in a direction in which the light diffusibility coincides with an incident light angle having substantially symmetry with respect to the incident light angle) as a columnar structure. The absolute value of the difference between the scattering center axis angle 113 and the scattering center axis angle of the columnar structure 123 is preferably 0 ° to 30 °. By setting the absolute value of the difference in scattering center axis angle within the above range, the effect of the present invention can be further enhanced. In order to realize this effect more effectively, the absolute value of the difference between the scattering center axis angle of the columnar structure 113 and the scattering center axis angle of the columnar structure 123 is more preferably 0 ° to 20 °. More preferably, the angle is 10 ° to 20 °. Note that the scattering center axis angle of the columnar structure 113 and the columnar structure 123 can be changed to a desired angle by changing the direction of light rays applied to the composition containing the sheet-like photopolymerizable compound. Can be adjusted.

  In addition to the above-described absolute value of the difference satisfying the above range, the absolute value of the difference between the azimuth angle of the scattering center axis of the columnar structure 113 and the azimuth angle of the scattering center axis of the columnar structure 123 is 0. It is preferable that it is (degree) -20 degree. As a result, the width of the diffusion region can be further increased without reducing the linear transmittance in the non-diffusion region of the anisotropic light diffusion layer.

  Here, each of the anisotropic light diffusing layers 110 and 120 may include a plurality of columnar region groups (a set of columnar structures having the same inclination, columnar regions) having different inclinations in a single layer. . In this case, the lower limit of the absolute value of the difference in scattering center axis angle in each columnar region group is preferably 5 °. On the other hand, the upper limit of the absolute value of the difference in scattering center axis angle is preferably 20 °, and more preferably 15 °.

  The polar angle θ (that is, the scattering center axis angle) of the scattering center axis P of the columnar structures 113 and 123 is preferably −60 ° to 0 ° or 0 ° to + 60 °, and −30 ° to 0 °. Or it is more preferable that it is 0 degree-+30 degree. When the scattering central axis angle is larger than + 60 ° or less than −60 °, contrast and luminance cannot be sufficiently improved.

<Refractive index>
The anisotropic light diffusion layers 110 and 120 are obtained by curing a composition containing a photopolymerizable compound. As the composition, the following combinations can be used.
(1) Using a single photopolymerizable compound (2) Using a mixture of a plurality of photopolymerizable compounds (3) A single or a plurality of photopolymerizable compounds, and a polymer compound not having photopolymerizability Used in combination

  In any of the above combinations, it is presumed that a micron-order fine structure having a different refractive index is formed in the anisotropic light diffusion layers 110 and 120 by light irradiation, which is shown in this embodiment. It seems that a unique anisotropic light diffusion characteristic is exhibited. Therefore, in the above (1), it is preferable that the refractive index change is large before and after photopolymerization, and in (2) and (3), it is preferable to combine a plurality of materials having different refractive indexes. Here, the refractive index change and the refractive index difference are specifically preferably 0.01 or more, more preferably 0.05 or more, and still more preferably 0.10 or more. It is.

  FIG. 8 shows the incident light angle at which the display light L irradiated from the light irradiation unit 31 provided in the HUD device 3 enters the above-described anisotropic optical film 100 (anisotropic light diffusion layer), and anisotropic optics. The display light L incident on the film 100 (anisotropic light diffusing layer) exits from the anisotropic optical film 100 (anisotropic light diffusing layer), that is, the display light has an anisotropic optical film (anisotropic light diffusing layer). ) And the angle of light emitted from the anisotropic optical film (anisotropic light diffusion layer).

  First, the anisotropic optical film 100 (anisotropic light diffusion layer) is in the direction of the scattering center axis direction (the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). For example, as described in the optical profile above, the incident light angle of −60 ° to −30 °, or + 30 ° to + 60 °, as compared with the linear transmittance when entering at P) shown in FIG. The linear transmittance becomes the maximum value, and the linear transmittance becomes the minimum value at an incident light angle of -20 to + 20 °. That is, in the anisotropic optical film 100 (anisotropic light diffusion layer), as the incident light angle is smaller than −20 ° or larger than + 20 °, the diffusion becomes weaker and the linear transmittance increases (light transmission increases). When the incident light angle is -20 ° to 20 ° close to the scattering central axis direction, the diffusion becomes stronger and the linear transmittance becomes weaker (light diffusion is given priority).

  In light of such properties of the anisotropic optical film 100 (anisotropic light diffusion layer), the light irradiation unit 31 provided in the HUD device 3, the reflection member 32, and the anisotropic optical film 100 (anisotropic light diffusion layer). It is necessary to define the arrangement relationship with

  As shown in FIG. 8, with respect to the incident light angle incident in the scattering center axis direction P (the normal direction of the film or layer is the direction when the scattering center axis angle is 0 ° and the incident light angle is 0 °). Then, the incident light angle range (see the optical profile described above and FIG. 4) in which the linear transmittance of the anisotropic optical film 100 (anisotropic light diffusion layer) is the maximum value, and the light irradiation unit 31 irradiates the reflection member 32. The incident light angle range in which the display light L reflected by the light is incident on the anisotropic optical film 100 (anisotropic light diffusion layer) is in the range of −60 ° to −30 °, or + 30 ° to + 60 °. It is necessary to be.

  Alternatively, the anisotropy with respect to the incident light angle incident in the scattering center axis direction P (the direction in which the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). An incident light angle range in which the linear transmittance of the optical film 100 (anisotropic light diffusion layer) is a maximum value (see the above optical profile and FIG. 4), and a display irradiated from the light irradiation unit 31 and reflected by the reflection member 32 The outgoing light angle range in which the light L is emitted with respect to the incident light incident on the anisotropic optical film 100 (anisotropic light diffusion layer) is both −60 ° to −30 °, or + 30 ° to + 60 °. Must be within range.

  That is, as shown in FIG. 8, the incident light angle side with respect to the scattering center axis direction P (the direction in which the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). , The incident light angle range in which the linear transmittance of the anisotropic optical film 100 (anisotropic light diffusion layer) is maximum with respect to the scattering central axis direction P, The incident light angle range in which the display light L emitted from the irradiation unit 31 and reflected by the reflecting member 32 is incident on the anisotropic optical film 100 (anisotropic light diffusion layer) is anisotropic with respect to the incident incident light. It is necessary that the angle range of outgoing light emitted from the neutral optical film 100 (anisotropic light diffusion layer) is in the range of −60 ° to −30 °, or + 30 ° to + 60 °.

  Thus, by prescribing the positional relationship between the light irradiation unit 31 provided in the HUD device 3, the reflection member 32, and the anisotropic optical film 100 (anisotropic light diffusion layer) based on the above-described relationship. Image blurring is less likely to occur, contrast can be improved, and luminance and viewing angle can be improved to a practical level.

  On the other hand, it is preferable to define the relationship with the incident light angle of external light with respect to the above-described arrangement relationship. FIG. 9 shows an anisotropic optical film 100 (anisotropic light) disposed in an opening 33 provided in a part of the housing 30 of the HUD device 3 in FIG. 1 in the present embodiment (first embodiment). It is the schematic block diagram seen from the side of the vehicle explaining a mode that external light M, such as sunlight, is diffused by a diffusion layer.

  At that time, the incident light angle at which the external light M is incident on the anisotropic optical film 100 (anisotropic light diffusing layer) through the windshield 40 is determined by the scattering central axis direction P of the anisotropic optical film 100 (anisotropic light diffusing layer). (For the normal direction of the film or layer, the direction when the scattering central axis angle is 0 ° and the incident light angle is 0 °), as described in the optical profile above (see also FIG. 4), − When incident at an incident light angle of 60 ° to -30 ° or + 30 ° to + 60 °, the linear transmittance is maximum, and when incident at an incident light angle of -20 to + 20 °, the linear transmittance is minimum. Value.

  Here, the incident light angle range in which the external light M enters the anisotropic optical film 100 (anisotropic light diffusion layer) through the windshield 40 is the scattering center axis direction P of the anisotropic optical film 100 (anisotropic light diffusion layer). When light is incident from within a range of −20 ° to + 20 ° with respect to the normal direction of the film or layer when the scattering central axis angle is 0 ° and the incident light angle is 0 °, external light In the anisotropic optical film 100 (anisotropic light diffusion layer), M is given priority to the diffusion of light, and thus the outgoing outside light N that is the diffused outgoing light is regularly reflected by the reflecting member 32, respectively. It will be led in a different direction. That is, most of the external light M does not reach the light irradiation unit 31 and is difficult to enter the light irradiation unit 31.

  However, the incident light angle from the external light M is the scattering center axis direction P of the anisotropic optical film 100 (anisotropic light diffusion layer) (the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). When the light is incident from an angle different from −20 ° to + 20 ° described above, the external light M is transmitted through the anisotropic optical film 100 (anisotropic light diffusion layer). Since the transmission is prioritized, the outgoing light that is transmitted without being diffused is regularly reflected by the reflecting member 32. Here, for example, it is most affected by outside light in one day. For the time zone (for example, noon), the anisotropic optical film 100 (anisotropic light diffusion layer) in the HUD device 3 is changed to the scattering central axis direction P (film or film) of the anisotropic optical film 100 (anisotropic light diffusion layer). The normal direction of the layer, the scattering center axis angle is 0 ° and the incident light angle If the positional relationship is such that the incident light angle range of the external light M is −20 ° to + 20 ° with respect to the direction (0 °), most of the light affected by the external light M is diffused. Therefore, the influence of external light can be sufficiently reduced.

  That is, the anisotropic optical film 100 (anisotropic light diffusing layer) in the HUD device 3 is arranged with respect to the external light in consideration of the external light described above, so that the external incident light from the outside of the windshield 40 can be obtained. The light M is reflected by the reflecting member 32 and reaches the light irradiation unit 31, and as a result of the display image becoming relatively thin, the effect of the phenomenon that the virtual image 50 becomes difficult to see (so-called washout) is sufficiently reduced. As a result, the contrast is increased and sufficient visibility can be ensured.

  Therefore, by using the anisotropic optical film 100 (anisotropic light diffusing layer) that has both the directivity and anisotropy and has the incident light angle dependency, the contrast is improved, the image blur is prevented, the luminance and the viewing angle are good. In addition to the above, sufficient visibility can be secured by sufficiently reducing the influence of external light. Note that the arrangement relationship in consideration of external light is not limited to the above-described arrangement relationship, and can be appropriately adjusted according to conditions such as a residential area, a climate, and a vehicle type.

(Second Embodiment)
A HUD device 4 according to the second embodiment will be described with reference to FIG. The second embodiment is different from the first embodiment in that the polarizing member 70 is placed on the surface of the anisotropic optical film 100 (anisotropic light diffusion layer) (on the plane, in FIG. On the sex member side). Here, the arrangement of the polarizing member 70 may be on the surface of the anisotropic optical film 100 (anisotropic light diffusion layer), and may not be in contact with the anisotropic optical film 100 (anisotropic light diffusion layer). Moreover, you may provide on the surface of a part of anisotropic optical film 100 (anisotropic light diffusion layer) with an area smaller than the surface of the anisotropic optical film 100 (anisotropic light diffusion layer). In addition, the same component as 1st Embodiment gives the same code | symbol, and demonstrates it.
As in the first embodiment, the opening 33 or the opening window has, for example, a transparent cover (dust-proof cover) made of glass or the like in order to prevent dust and dirt from entering the HUD device 4. ) May be provided.

  As described above, for example, in a situation where strong external light from the sun arrives during the daytime in fine weather, the external light M incident from the outside of the windshield 40 is reflected by the reflecting member 32. As a result, the light irradiation unit 31 is reached and the display image becomes relatively thin. As a result, there is a problem in that the virtual image 51 becomes less visible (so-called washout).

  Therefore, as in the second embodiment, by providing the polarizing member 70 on the surface of the anisotropic optical film 100 (anisotropic light diffusion layer), the amount of external light M such as sunlight incident through the windshield 40. In principle, about half of the light intensity is absorbed by the polarizing member 70, so that in addition to the operational effects of the first embodiment described above, the external light M incident on the front surface of the light irradiation unit 31 is further increased. By reducing the influence of the phenomenon (so-called washout) that makes it difficult to see the virtual image 51 due to external light in order to make it difficult to be incident, the contrast is increased more than in the first embodiment, which is sufficient. High visibility can be secured.

  Here, the polarizing member 70 refers to a polarizing plate, a polarizing film, or the like, and refers to a polarizer that generates linearly polarized light from natural light (non-polarized light). Specifically, for example, a wire grid type polarizer made of an inorganic material that obtains polarization characteristics by forming a fine metal grid (slit shape) on the surface of glass, or iodine in polyvinyl alcohol (PVA). Resin sheet type polarizer produced by stretching a film impregnated with a dichroic dye such as a crystal in a certain direction, a crystal type polarizer using a crystalline material such as mica and quartz, and an optical multilayer film A high purity straight line that removes a linearly polarized light component in one direction by total reflection by combining a polarizer of PBS (Polarizing Beam Splitter) type and a calcite prism that is a birefringent crystal. Glan-Thompson prism type polarizer, which is a polarizer for obtaining polarized light, and inorganic absorption composed of inorganic materials A type-type polarizer or the like can be applied. The polarizing member 70 is not limited to this, and may be any member that absorbs and transmits external light such as sunlight, light that vibrates in a certain direction and light that has vibration orthogonal thereto. Further, the shape and configuration are not particularly limited.

<Relationship between the polarization axis (absorption axis) of the polarizing member 70 and the polarization axis (absorption axis) of the second polarizing plate 39 of the light irradiation unit 31>
Next, the relationship between the polarizing member 70 and the second polarizing plate (display light emission side polarizing plate) 39 included in the light irradiation unit 31 when the light irradiation unit 31 includes a polarizing plate will be described with reference to FIG. .

  First, as the light irradiation unit 31, a liquid crystal display with a backlight may be used for irradiating the display light L. In this case, for example, as shown in FIG. 11, the light irradiating unit 31 moves back in order from the rear in the vehicle front-rear direction (right side in FIG. 11: eye point EP side) to the front (left side in FIG. 11: virtual image 51 side). A light 34, a first polarizing plate (backlight incident side polarizing plate) 35 constituting a liquid crystal display, a first electrode substrate (backlight incident side electrode substrate) 36, a liquid crystal layer 37, and a second electrode substrate (display) A light emitting side electrode substrate) 38 and a second polarizing plate (display light emitting side polarizing plate) 39.

Here, in FIG. 11, the second polarizing plate (display light emission side polarizing plate) 39 and the polarizing member 70 are arranged so that the absorption axis direction coincides (is parallel).
That is, the second polarizing plate (display light emission side polarizing plate) 39 and the polarizing member 70, for example, absorb light having a polarization component along the same absorption axis (for example, referred to as P wave in FIG. 11). , The light of the polarization component along the same transmission axis (for example, referred to as S wave in FIG. 11) is transmitted.

  In FIG. 11, the P wave and the S wave are indicated by double arrows. As shown in FIG. 11, when the P wave and the S wave included in the external light M such as sunlight are incident through the windshield 40, the P wave is absorbed by the polarizing member 70 out of the P wave and the S wave, Only the S wave is transmitted. As a result, the amount of external light M such as sunlight incident through the windshield 40 is absorbed (blocked) by the polarizing member 70 and can be reduced to about half the amount of light in principle.

  On the other hand, the S wave of the display light L transmitted through the second polarizing plate (display light emission side polarizing plate) 39 is incident on the polarizing member 70 through the reflecting member 32 and the anisotropic light diffusion layer 100. Become. And since the polarizing member 70 has the same transmission axis as the 2nd polarizing plate (display light emission side polarizing plate) 39, it can permeate | transmit an S wave.

  Therefore, when the second polarizing plate (display light emission side polarizing plate) 39 and the polarizing member 70 are arranged so that the absorption axis direction coincides (is parallel), the virtual image 51 can be seen by external light. The influence of a phenomenon that is difficult (so-called washout) can be reduced as compared with the first embodiment, and the contrast is higher than that of the first embodiment, so that sufficient visibility can be ensured.

  Note that the arrangement relationship in consideration of external light is not limited to the above-described arrangement relationship, and can be appropriately adjusted according to conditions such as a residential area, a climate, and a vehicle type.

  The above-described components in the first embodiment can be similarly applied and applied in the present embodiment.

(Third embodiment)
A HUD device 3 according to a third embodiment will be described with reference to FIG. In the third embodiment, an anisotropic optical film 400 (anisotropic light diffusion layer) is provided on the driver-side surface of the windshield 40 as compared to the first embodiment. The same constituent elements as those in the first and second embodiments will be described with the same reference numerals. The anisotropic optical film 400 (anisotropic light diffusing layer) applies the same anisotropic optical film (anisotropic light diffusing layer) as the anisotropic optical film 100 (anisotropic light diffusing layer) described above.
As in the first embodiment, in order to prevent dust and dirt from entering the HUD device 3 in the opening 33 or the opening window, for example, a transparent cover made of glass or the like (dust-proof cover) is used. ) May be provided.

  As described above, the light irradiation unit 31 is provided inside the housing 30 of the HUD device 3. When the display light L from the light irradiation unit 31 is applied to the windshield 40, the display light L may generate double virtual image light. Therefore, in such a case, the visibility of the display image has been reduced.

  Therefore, as shown in FIG. 12, by providing the above-described anisotropic optical film 400 (anisotropic light diffusion layer) on the driver-side surface of the windshield 40, the display light L is converted into the anisotropic optical film 400 (anisotropic light). The diffusion layer) makes it possible to achieve an appropriate balance between diffusion and light collection, so that double virtual image light can be prevented and contrast can be improved as compared with the first embodiment. Further, for the external light M, as in the first embodiment, the incident light angle from the external light M having the greatest influence on the visibility is the scattering center of the anisotropic optical film 400 (anisotropic light diffusion layer). Diffusion of light is prioritized with respect to the axial direction P (the direction in which the normal direction of the film or layer is 0 ° for the scattering center axis angle and the incident light angle is 0 °). If the anisotropic optical film 400 (anisotropic light diffusing layer) having a scattering center axis angle that can be changed can be prevented from being incident on the light irradiation unit 31 of the external light M, the virtual image 52 can be seen. The influence of a phenomenon that is difficult (so-called washout) can be reduced as compared with the first embodiment, and the contrast is higher than that of the first embodiment, so that sufficient visibility can be ensured.

  In addition, as shown in FIG. 12, the incident light angle from the external light M is determined so that the scattering center axis direction P of the anisotropic optical film 400 (anisotropic light diffusion layer) (the normal direction of the film or layer is the scattering center axis). The center of scattering is such that it can be -60 ° to -30 ° or + 30 ° to + 60 ° with respect to light transmission with respect to the angle 0 ° and the incident light angle 0 °. In the case of the anisotropic optical film 400 having an angle (anisotropic light diffusion layer), the scattering center axis direction P of the anisotropic optical film 100 (anisotropic light diffusion layer) (the normal direction of the film or layer is defined as the scattering center). Anisotropic optical film 100 having a scattering central axis angle that can be -20 ° to + 20 ° in which the diffusion of light is prioritized (the direction when the axial angle is 0 ° and the incident light angle is 0 °). In the case of an (anisotropic light diffusion layer), the external light M is an anisotropic optical film. Therefore, the diffusion of the external light M by the anisotropic optical film 100 (anisotropic light diffusion layer) is mainly performed. It can be suppressed.

  Conversely, the incident light angle from the external light M is the scattering center axis direction P of the anisotropic optical film 400 (anisotropic light diffusion layer) (the normal direction of the film or layer is 0 ° and the scattering center axis angle is 0 ° and the incident angle is 0 °). An anisotropic optical film 400 (an anisotropic light diffusing layer) having a scattering central axis angle that can be −20 ° to + 20 °, in which light diffusion is prioritized with respect to the direction when the light angle is 0 °. The scattering center axis direction P of the anisotropic optical film 100 (anisotropic light diffusion layer) (the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). The anisotropic optical film 100 having a scattering center axis angle (anisotropy light diffusion) such that the direction of light transmission can be −60 ° to −30 °, or + 30 ° to + 60 °, in which light transmission is given priority. Layer), the external light M is anisotropic optical film 40. Since the light is diffused by the (anisotropic light diffusion layer), the diffusion of the external light M by the anisotropic optical film 100 (anisotropic light diffusion layer) is mainly suppressed. It will be possible to.

  That is, by installing the anisotropic optical film 400 (anisotropic light diffusion layer) on the driver side surface of the windshield 40, the anisotropic optical film 400 (anisotropic light diffusion layer) and the anisotropic optical film 100 (different It can have the advantage that the degree of freedom can be increased with respect to the design of the scattering center axis angle of the isotropic light diffusion layer).

  The anisotropic optical film 400 (anisotropic light diffusion layer) may be provided in a partial region of the windshield 40 driver-side surface, or provided in the entire area of the windshield 40 driver-side surface. Also good. In addition, when providing in the one part area | region of the driver | operator side surface of the windshield 40, it is essential that it is on the optical path of the display light L, Furthermore, the anisotropic optics which considered the spreading | diffusion of the external light M mentioned above The scattering center axis angle of the film 400 (anisotropic light diffusion layer) is preferably set.

  The anisotropic optical film 400 (anisotropic light diffusing layer) is not necessarily used simultaneously with the anisotropic optical film 100 (anisotropic light diffusing layer), only the anisotropic optical film 400 (anisotropic light diffusing layer). It is good also as a structure of.

  Furthermore, the arrangement relationship in consideration of external light is not limited to the above-described arrangement relationship, and can be appropriately adjusted according to conditions such as a residential area, a climate, and a vehicle type.

  In addition, the above-described components in the first embodiment can be applied and applied in the same manner in this embodiment.

(Fourth embodiment)
A HUD device 5 according to a fourth embodiment will be described with reference to FIG. The fourth embodiment is different from the first embodiment in that the projection area 43 of the display light L emitted from the light irradiation unit 31 is not the windshield 40 but the combiner 44. The same constituent elements as those in the first to third embodiments will be described with the same reference numerals.
As in the first embodiment, in order to prevent dust and dust from entering the HUD device 5 in the opening 33 or the opening window, for example, a transparent cover made of glass or the like (dust-proof cover) is used. ) May be provided.

  The HUD device 5 is accommodated inside the instrument panel 42. The HUD device 5 includes a housing 30 and an opening 33 provided in a part of the housing 30, and the display light L representing a display image from the opening 33 toward the outside of the instrument panel 42. Can be irradiated.

  Here, the combiner 44 is installed on the display light L optical path between the opening 33 and the windshield 40. In FIG. 13, on the instrument panel 42 in the vicinity of the opening 33, in a vehicle in a stationary state, the direction along the gravity is the downward direction, and the direction opposite to the downward direction is the upward direction. On the other hand, the state in which the thin plate-shaped combiner 44 is installed in an inclined state is shown, but the installation state is not particularly limited. For example, a stand or holder used in a portable car navigation system is used as the combiner 44. In addition to the instrument panel 42 and the windshield 40, it is also preferable to install and use it on a sun visor (not shown). In short, as long as the combiner 44 is installed on the display light L optical path between the opening 33 and the windshield 40, its configuration and installation method are not limited.

  The combiner 44 is an optical element, and is a half mirror having a function of reflecting a part of incident light and transmitting a part thereof. That is, the combiner 44 reflects the light incident from the surface on the driver side and guides it to the eye point (viewpoint) EP, and transmits the light incident from the surface on the windshield side and guides it to the eye point (viewpoint) EP.

  A light irradiation unit 31 is provided in the HUD device 5. The light irradiation unit 31 is a member that irradiates display light L representing a display image, for example, a video projection device, and specifically includes, for example, a liquid crystal display with a backlight (not shown). In the case of a liquid crystal display with a backlight, the display image of the liquid crystal display is irradiated by the backlight, and the display light L is irradiated toward the reflecting member 32 on the side opposite to the backlight. The display light L is reflected on the surface of the reflecting member 32, travels to the driver side surface of the combiner 44 arranged outside the opening 33, and then travels to the eye point (viewpoint) EP.

  Compared with the first embodiment, the present embodiment is such that the projection area 43 of the display light L emitted from the light irradiation unit 31 is not the windshield 40 but the combiner 44. Since the state is not particularly limited, like the first embodiment, this embodiment has good contrast improvement, prevention of image blurring, good brightness and viewing angle, and sufficiently reduces the influence of external light. Thus, not only can sufficient visibility be ensured, but also the degree of freedom in the configuration of the components in the HUD device 5 (including the design of the scattering center axis angle of the anisotropic optical film 100 (anisotropic light diffusion layer)). ) Can be increased.

  As in the first embodiment, in order to prevent dust and dust from entering the HUD device 5 in the opening 33 or the opening window, for example, a transparent cover made of glass or the like (dust-proof cover) is used. ) May be provided.

  Furthermore, the arrangement relationship in consideration of external light can be appropriately adjusted according to conditions such as the residential area, climate, and vehicle type.

  In addition, the above-described components in the first embodiment can be applied and applied in the same manner in this embodiment.

(Fifth embodiment)
A HUD device 6 according to a fifth embodiment will be described with reference to FIG. 5th Embodiment remove | excludes a reflective member from a component with respect to 1st Embodiment. The same constituent elements as those in the first to fourth embodiments will be described with the same reference numerals.

  As in the first embodiment, in order to prevent dust and dirt from entering the HUD device 6 in the opening 35 or the opening window, for example, a transparent cover made of glass or the like (dust-proof cover) is used. ) May be provided.

  The HUD device 6 is accommodated inside the instrument panel 42. The HUD device 6 includes a housing 34 and an opening 35 provided in a part of the housing 34, and the display light L that represents a display image from the opening 35 toward the outside of the instrument panel 42. Can be irradiated.

  A light irradiation unit 31 is provided in the HUD device 6. The light irradiation unit 31 is a member that irradiates display light L representing a display image, for example, a video projection device, and specifically includes, for example, a liquid crystal display with a backlight (not shown). In the case of a liquid crystal display with a backlight, the display image of the liquid crystal display is irradiated by the backlight, and the display light L is irradiated toward the anisotropic optical film 100 (anisotropic light diffusion layer) on the side opposite to the backlight. It has come to be. The display light L is directed to the projection area 45 on the driver side surface of the windshield 40 and then to the eye point (viewpoint) EP.

  As shown in FIG. 14, in the fifth embodiment, the reflecting member is excluded from the constituent elements. Therefore, the size of the HUD device 6 can be reduced as compared with the other embodiments. The degree of freedom of installation in the vehicle 6 can be increased, and the cost can be reduced.

  Moreover, in this embodiment, a virtual image is expanded on the optical path of the display light L between the light irradiation part 31 in the HUD apparatus 6 and the anisotropic optical film 100 (anisotropic light diffusion layer) as needed. A lens (for example, on an aspheric surface) that can be used may be installed.

  The present embodiment is different from the first embodiment in that the reflecting member is excluded from the constituent elements, but the anisotropic optical film 100 having an incident light angle dependency that has both directivity and anisotropy (different Since the isotropic light diffusing layer is a constituent element in the HUD device 6, as in the first embodiment, the contrast improvement, image blur prevention, brightness and viewing angle are good, and the influence of external light is sufficiently reduced. Thus, not only can sufficient visibility be ensured, but also the degree of freedom of installation of the HUD device 6 in the vehicle can be increased, and costs can be reduced. In addition, regarding the arrangement relationship in consideration of outside light, it can be appropriately adjusted according to conditions such as a residential area, a climate, and a vehicle type. The above-described components in the first embodiment can be similarly applied and applied in the present embodiment.

  It should be noted that each of the above-described embodiments should not be construed as being limited to the configuration shown in the drawings, and each component can be combined in various ways.

For example, the driver of the anisotropic optical film 100 (anisotropic light diffusion layer) and the polarizing member 70 in the second embodiment shown in FIG. 10 and the windshield 40 in the third embodiment shown in FIG. The anisotropic optical film 400 (anisotropic light diffusion layer) provided on the side surface is combined, and the anisotropic optical film (anisotropic light diffusion layer) / polarizing member / anisotropic optics in order from the incident side of the display light L. It may be a constituent element of the HUD device in an arrangement relationship such as a film (anisotropic light diffusion layer).
Further, the anisotropic optical film 100 (anisotropic light diffusion layer) and the polarizing member 70 in the second embodiment shown in FIG. 10 and the combiner 44 in the fourth embodiment shown in FIG. 13 are combined. May be.

  In addition, the anisotropic optical film 100 in the present embodiment is configured by stacking two or more anisotropic light diffusion layers as well as a single anisotropic light diffusion layer, as in the definition of the anisotropic optical film described above. (At that time, the anisotropic light diffusion layer may be laminated via an adhesive layer or the like).

  As described above, in the anisotropic optical film 100 (anisotropic light diffusing layer), the incident light angle from the outside light has a scattering central axis direction P (film or layer) of the anisotropic optical film 100 (anisotropic light diffusing layer). When the normal direction is -20 ° to + 20 ° with respect to the scattering center axis angle of 0 ° and the incident light angle of 0 °, the diffusion of light is prioritized.

  In this case, the diffusion range of the outgoing light (outgoing light angle range) is specifically set to a reference value with a value (for example, + 20 ° if −20 °) changed in sign of the incident light angle as a reference value. This is a range obtained by adding the plus or minus of the absolute value of the incident light angle value (for example, if + 20 ° is the reference value, 20 ° is the absolute value, and the + 20 ° reference value is + 20 ° and −20 °. Since the added range, that is, 0 ° to 40 ° becomes the diffusion range (exiting light angle range) of the outgoing light), the scattering center axis direction P (film or layer) of the anisotropic optical film 100 (anisotropic light diffusion layer) When the incident light angle is −20 ° to + 20 ° with respect to the normal direction of the light beam with respect to the scattering central axis angle of 0 ° and the incident light angle of 0 °, Projection angle range) is −40 ° to + 40 °.

  When the anisotropic optical film 100 (anisotropic light diffusion layer) having this property is, for example, an anisotropic optical film in which two anisotropic light diffusion layers are laminated, the anisotropic light diffusion of the first layer on the outside light incident side is performed. The external light diffused by the layer is further diffused by the second anisotropic light diffusion layer. In addition, the light transmission is given priority in the scattering center axis direction P of each anisotropic light diffusion layer (direction assuming that the normal direction of the layer is the scattering center axis angle 0 ° and the incident light angle 0 °). If the anisotropic light diffusing layer having a scattering center axis angle that can be -60 ° to -30 ° or + 30 ° to + 60 ° is disposed, the display light L is transmitted. There is no effect on L. For this reason, the influence of external light can be further reduced.

  Further, when the HUD device is applied to an automobile, the arrangement relationship between the windshield 40, the components in the HUD device, and the combiner 44 (depending on the application) is fixed. The fact that the arrangement relationship is fixed means that the optical path of the display light L is fixed.

Under such circumstances, it is meaningful to use the anisotropic optical film 100 (anisotropic light diffusion layer), which is a light diffusion film having an incident light angle dependency. That is, by using the anisotropic optical film 100 (anisotropic light diffusing layer) having both anisotropy and directivity, the incident light angle from outside light is such that the anisotropic optical film (anisotropic light diffusing layer) -20 ° to + 20 ° which is close to the scattering center axis direction with respect to the scattering center axis direction P (the direction in which the normal direction of the film or layer is 0 ° and the incident light angle is 0 °). If the configuration is such that the incident light is incident in the incident light angle range, diffusion of the external light is given priority, and the diffusion range of the emitted light (emitted light angle range) is a predetermined range corresponding to the incident light angle range. (In this case, −40 ° to + 40 °). That is, the influence of external light can be reduced. As a result, most of the outside light is not easily incident on the light irradiation unit 31, and the influence of a phenomenon (so-called washout) that makes it difficult to see a virtual image is sufficiently reduced to increase the contrast. Visibility can be ensured.
Further, with respect to the display light L representing the display image irradiated from the light irradiation unit 31, the incident light angle from the external light has a scattering central axis direction P (film or layer) of the anisotropic optical film (anisotropic light diffusion layer). -60 ° to -30 ° or + 30 ° to + 60 ° away from the direction of the scattering center axis with respect to the normal direction of the above (the direction when the scattering center axis angle is 0 ° and the incident light angle is 0 °) If the configuration is such that the incident light is incident at an incident light angle, the display light L is given priority for transmission and is transmitted through the anisotropic optical film (anisotropic light diffusion layer). ) Hardly occur and the contrast can be improved.

  In the present embodiment, the anisotropic optical film 100 (anisotropic light diffusion layer) includes a louver structure anisotropic light diffusion layer 110 (20) and a pillar structure anisotropic light diffusion layer 120 (10). Explained. As described above, when the HUD device is applied to an automobile, the display position of the virtual image from the windshield 40 or the combiner 44 is fixed when the HUD device is applied to the automobile. It will be fixed. At this time, it may be difficult to cope with a change in the eye point (viewpoint) EP height position of the driver. Note that the variation in the height position of the driver's eye point (viewpoint) EP may be caused by, for example, the height of the driving user when the vehicle is used by a plurality of users.

  Here, in the anisotropic light diffusion layer 110 (20) having the louver structure, as can be seen from the state of the transmitted light in FIG. 2B, the transmitted light has a substantially needle shape, and the MD direction and the TD direction. And light diffusivity are greatly different. That is, in the anisotropic light diffusing layer 20 having the louver structure, the diffusion has a directivity having a large diffusion characteristic depending on the azimuth angle. Specifically, in the example shown in FIG. 2, diffusion is wider in the MD direction than in the case of the pillar structure, but diffusion is narrower in the TD direction than in the case of the pillar structure.

  Utilizing this property, for example, the front-rear direction of the vehicle and the MD direction of the anisotropic light diffusion layer 110 having the louver structure (the same direction as the MD direction in FIG. 2B and the minor axis SA side direction of the columnar structure 113 in FIG. 6A). The vehicle width direction of the vehicle and the TD direction of the anisotropic light diffusion layer 110 of the louver structure (the same direction as the TD direction in FIG. 2 (b), the direction of the major axis LA of the columnar structure 113 in FIG. 6A) are matched. In the first embodiment, the anisotropic light diffusion layer 110 having a louver structure is provided so as to close the opening 33 which is a part of the housing 30 in the HUD device 3 of FIG.

  With such a configuration, in this case, the virtual image 50 from the windshield 40 is widened by diffusion in the MD direction, and the MD direction is the height position of the driver's eye point (viewpoint) EP. Therefore, the driver's burden can be reduced as much as possible when viewing the virtual image 50. Moreover, even if it is the structure using the virtual image from the combiner instead of the windshield 40, it is possible to obtain the same effect as described above.

  In the present embodiment, the HUD device is described as being housed in the instrument panel 42, but may be installed in the instrument panel (instrument cluster). In this case, the opening (opening window) can be appropriately installed in the instrument panel depending on the application.

  In the present embodiment, the HUD device is described as being applied to an automobile. However, the present invention is not limited to this. For example, an aircraft, a train, a construction vehicle, a game device (for example, a pachinko machine, It may also be applicable to display of slots, etc.), game devices, medical devices, and the like.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these examples.

<< Manufacture of anisotropic optical film >>
The anisotropic optical film (anisotropic light diffusion layer) of the present invention was produced by an existing method (for example, JP-A-2006-119241) described below.

<Pillar structure>
A partition wall having a height of 200 μm was formed with a curable resin on the entire periphery of the edge of a PET film having a thickness of 75 μm and a size of 76 × 26 mm (trade name: A4300, manufactured by Toyobo Co., Ltd.). The following ultraviolet curable resin composition was dropped into this and covered with another PET film.
-50 parts by weight of 2- (perfluorooctyl) -ethyl acrylate (61% fluorine content, manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light acrylate FA-108)
・ 50 parts by weight of 1,9-nonanediol diacrylate (fluorine-free, manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light acrylate 1.9ND-A)
-4-Hydroxy-2-methyl-1-phenylpropan-1-one 4 parts by weight (Ciba Specialty Chemicals, trade name: Darocur 1173)
An irradiation intensity of 30 mW / cm is perpendicular to the epi-illumination irradiation unit of a UV spot light source (manufactured by Hamamatsu Photonics, Inc., product name: L2859-01) with respect to a liquid film having a thickness of 200 μm sandwiched between PET films. ² of ultraviolet parallel light was irradiated for 1 minute, FIGS. 2 (a) or anisotropic light-diffusing layer of the pillar structure having a large number of different rod-shaped fine columnar structure refractive index as shown in FIG. 6 (b) Got.

<Louvre structure>
The UV curable resin composition in the state of being sandwiched between the same PET films as the pillar structure described above, the parallel rays emitted from the epi-illumination irradiation unit of the UV spot light source described above, and the transmitted light has an aspect ratio of 25 UV rays, which are linear rays converted through a directional diffusing element, are vertically irradiated for 1 minute at the same irradiation intensity as that of the pillar structure described above, and are refracted as shown in FIG. 2 (b) or FIG. 6 (a). An anisotropic light diffusing layer having a louver structure having many substantially plate-like minute columnar structures having different rates was obtained.

Here, the anisotropic light diffusion layers used in the examples described below are of two types, the pillar structure and the louver structure described above, and each exhibited light diffusivity having a linear transmittance shown in FIG. Each scattering center axis angle was about 0 ° with respect to the normal direction of the layer, and the diffusion width was about −20 ° to + 20 ° based on the scattering center axis angle.
Moreover, when using the anisotropic light-diffusion layer for the driver | operator side surface of a windshield, the anisotropic light-diffusion layer of the louver structure mentioned above was used.

<Evaluation equipment>
Regarding the HUD apparatus used for the evaluation of the examples described below, the light irradiation unit is a liquid crystal projector, the reflecting member is a commercially available mirror, the polarizing member is a transparent hard coat having a transmittance of 42% and a polarization degree of 99.9%. Using the processed polarizing plate for liquid crystal display, it was comprised in the instrument panel in a vehicle with the above-mentioned anisotropic light-diffusion layer similarly to embodiment. The combiner is in a state where the concave side is covered with a beam splitter coat and the convex side is covered with an anti-reflection coat and a half mirror with a reflectance of 40% is tilted and fixed by a holder used in a car navigation system. Provided.
In addition, when installing the HUD device and the combiner in the car, the display light emitted from the liquid crystal projector is applied to the anisotropic light diffusion layer provided so as to close the opening provided in a part of the housing of the HUD device. The incident light angle was arranged so as to be at a position of about 45 ° from the plane (layer) normal direction of the anisotropic light diffusion layer.

Example 1
The above-described evaluation device is provided with an anisotropic light diffusion layer having a pillar structure so as to be closed in an opening provided in a part of the housing of the HUD device, and has the same configuration as that of the first embodiment. went. The constituent elements of Example 1 are shown in Table 1, and the evaluation results of optical characteristics (luminance, contrast, blurring, viewing angle) are shown in Table 2.

(Example 2)
With the evaluation device described above, an anisotropic light diffusion layer having a louver structure is provided so as to close the opening provided in a part of the housing of the HUD device, and the configuration is the same as in the first embodiment. went. The constituent elements of Example 2 are shown in Table 1, and the evaluation results of optical characteristics (luminance, contrast, blurring, viewing angle) are shown in Table 2.

(Example 3)
The above-described evaluation device is provided with an anisotropic light diffusion layer having a pillar structure so that the opening provided in a part of the housing of the HUD device is closed, and the surface of the anisotropic light diffusion layer on the outside light incident side of the pillar structure is provided. Same as in the second embodiment, provided on the upper side (translucent member side) is the above-described polarizing member (polarizing plate for a liquid crystal display having a transmittance of 42% and a polarization degree of 99.9% and subjected to a transparent hard coat treatment). The configuration was evaluated. The constituent elements of Example 3 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

Example 4
An external light incident side surface of the anisotropic light diffusion layer of the louver structure is provided by providing the anisotropic light diffusion layer of the manufactured louver structure so as to close the opening provided in a part of the housing of the HUD device by the evaluation device described above. The above polarizing member (a polarizing plate for a liquid crystal display treated with a transparent hard coat having a transmittance of 42% and a degree of polarization of 99.9%) is provided on the same configuration as in the second embodiment and evaluated. It was. The constituent elements of Example 4 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Example 5)
An external light incident side surface of the anisotropic light diffusion layer of the louver structure is provided by providing the anisotropic light diffusion layer of the manufactured louver structure so as to close the opening provided in a part of the housing of the HUD device by the evaluation device described above. The above-described polarizing member (transparent hard-coated polarizing plate with a transmittance of 42% and a polarization degree of 99.9%) is provided on the upper side (translucent member side), and the windshield driver An anisotropic light diffusion layer having a louver structure was provided on the side surface, and a composite configuration of the second embodiment and the third embodiment was evaluated. The constituent elements of Example 5 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Example 6)
With the evaluation device described above, an anisotropic light diffusing layer with a prepared pillar structure is provided so as to close the opening provided in a part of the housing of the HUD device, and the combiner is mounted on the instrument panel near the opening by a car navigation system. The holder used was fixed in an inclined state, and the configuration was the same as in the fourth embodiment, and evaluation was performed. The constituent elements of Example 6 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Example 7)
With the evaluation device described above, an anisotropic light diffusing layer with a prepared pillar structure is provided so as to close an opening provided in a part of the housing of the HUD device, and the configuration is the same as that of the fifth embodiment. It was. The constituent elements of Example 7 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Comparative Example 1)
Except that the evaluation device described above provided a transparent glass plate (haze of about 1%) instead of the anisotropic light diffusing layer so as to close the opening provided in a part of the housing of the HUD device. The same configuration as in No. 1 was evaluated. The constituent elements of Comparative Example 1 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Comparative Example 2)
An isotropic light diffusing layer in which fine particles are dispersed instead of the anisotropic light diffusing layer (haze: about 29%, total light transmittance) so as to close the opening provided in a part of the housing of the HUD device by the evaluation device described above. The configuration was the same as that of Example 1 except that about 90%) was provided. The constituent elements of Comparative Example 2 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

(Comparative Example 3)
An isotropic light diffusing layer in which fine particles are dispersed instead of the anisotropic light diffusing layer (haze: about 29%, total light transmittance) so as to close the opening provided in a part of the housing of the HUD device by the evaluation device described above. A polarizing plate for a liquid crystal display in which a transparent hard coat treatment with a transmittance of 42% and a degree of polarization of 99.9% is performed on the surface of the isotropic light diffusing layer on the outside light incident side. The evaluation was performed with the same configuration as in Example 3, except that The constituent elements of Comparative Example 3 are shown in Table 1, and the optical characteristics (brightness, contrast, blur feeling, viewing angle) evaluation results are shown in Table 2.

<< Evaluation method >>
Regarding each evaluation apparatus of the above-mentioned Examples and Comparative Examples, the optical characteristics were evaluated as follows.

  Optical properties were evaluated by visual evaluation from the viewpoint of visibility with respect to luminance (bright place and dark place), contrast (dark place), blur feeling, and viewing angle (in view point). Specifically, five types of different display images are prepared, and each driver is visually recognized by 10 drivers, and the feelings obtained by each driver are scored according to the score criteria provided for each evaluation item ( Each item was rated 5 points), and the average value for the total for each evaluation item was calculated and used as the result of this evaluation.

<Scoring criteria for evaluation items>
The scoring criteria for each evaluation item in Table 2 are as follows. In addition, as numerical values, 3 or more are good as evaluation items, and less than 3 are bad.
"Brightness (light and dark)"
1 (dark) to 5 (bright)
"Contrast (light)"
1 (light) to 5 (dark)
"Bokeh feeling"
1 (strong) to 5 (weak)
"Viewing angle (in view)"
1 (narrow) to 5 (wide)
"Total (total points)"
13.0 or more: sufficient visibility as a HUD device.
Less than 13.0: Visibility is not sufficient as a HUD device.

  In addition to the above evaluation, the degree of the double virtual image in the virtual image was confirmed visually by 10 drivers as in the above evaluation for each example and comparative example. The best results were obtained in the degree of double virtual images.

<< Evaluation results >>
As shown in Table 2, the embodiment of the present invention shows good characteristics as a whole in terms of brightness, contrast, blur, and viewing angle, and has sufficient visibility as a HUD device. On the other hand, in any of the above-mentioned evaluation items, the comparative example was inferior to the example of the present invention, and the visibility as a HUD device was not sufficient. In particular, in Examples 3 to 5, a high contrast can be obtained among the examples. In addition, in Example 5, the total (total point) is the highest, and the HUD device is the highest in this example. High visibility was obtained.

  In addition, since Example 5 uses an anisotropic light diffusion layer on the driver side surface of the windshield, when installing in the instrument panel in the car, the anisotropic optical film used at each location It was very advantageous for selectivity.

  Further, in Example 6, since a combiner was used instead of the windshield, the degree of freedom of configuration of each component in the HUD device was increased, which was very advantageous for installation.

  And since Example 7 remove | excluded the reflective member from the component, the installation freedom degree in the vehicle of a HUD apparatus was high, and the expense was the least compared with the other Example.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment. That is, other forms that can be conceived by those skilled in the art or various modifications within the scope of the invention described in the claims also belong to the technical scope of the present invention.

3, 4-6 HUD device (display device, head-up display)
30, 34 Housing 31 Light irradiation part 32 Reflective member 33, 35 Opening part 44 Combiner (translucent member)
40 Windshield (Translucent member)
41, 43, 45 Projection area 42 Instrument panel 50-54 Virtual image 70 Polarizing member EP Eye point (viewpoint)
100 Anisotropic optical film (anisotropic light diffusion layer)
400 Anisotropic optical film (anisotropic light diffusion layer)
L Display light M External light (sunlight, etc.)
N Outgoing light P Scattering central axis direction

Claims (8)

A display device that emits display light representing a display image toward a translucent member and displays the display image as a virtual image so as to be visible,
A housing disposed below the translucent member;
A light irradiation unit for irradiating the display light provided in the housing;
An anisotropic light diffusing layer disposed in the casing and having a linear transmittance that varies in accordance with an incident light angle of the display light or external light, and having a matrix region and a columnar region that is a plurality of columnar structures An anisotropic optical film comprising at least a layer;
Comprising at least
The display device, wherein the anisotropic optical film is disposed on a part of the casing located on the display light optical path between the light irradiation unit and the translucent member. The casing has an opening that allows the display light to pass from the inside of the casing toward the translucent member outside the casing;
The display device according to claim 1, wherein the anisotropic optical film is disposed so as to close the opening.   The display device according to claim 1, wherein the display device includes a reflection unit that reflects the display light emitted from the light irradiation unit to the translucent member outside the housing. .   The display device according to claim 1, wherein a polarizing member is provided on the light-transmissive member side of the anisotropic optical film. The light irradiation unit includes an emission side polarizing plate disposed on the side from which the display light is emitted,
The exit side polarizing plate and the polarizing member are:
The display device according to claim 4, wherein the display unit is arranged such that a polarization axis of the output-side polarizing plate and a polarization axis of the polarizing member coincide with each other. The anisotropic light diffusion layer has at least one scattering central axis;
The anisotropic light diffusing layer has increased diffusibility with respect to the display light or external light incident in a predetermined angle range, shows a minimum linear transmittance, and is incident in an angle range other than the predetermined angle range. The diffusibility decreases with respect to the display light or outside light, and the linear transmittance shows the maximum value,
The predetermined angle range is −20 ° to + 20 ° when the normal direction of the anisotropic light diffusion layer is based on the scattering center axis angle and the incident light angle,
The angle range other than the predetermined angle range is −30 ° to −60 ° or + 30 ° to + 60 ° when the normal direction of the anisotropic light diffusion layer is based on the scattering center axis angle and the incident light angle. The display device according to claim 1, wherein the display device is provided.   The plurality of columnar structures are configured by being oriented from one surface of the anisotropic light diffusion layer to the other surface, and an aspect ratio of an average minor axis to an average major axis is less than 2. The display apparatus of 1-6.   The plurality of columnar structures are configured by being oriented from one surface of the anisotropic light diffusion layer to the other surface, and an aspect ratio between an average minor axis and an average major axis is 2 or more. The display apparatus of 1-7.