Projection image display member, transparent display system, head-up display system, manned transportation machine, and screen

Abstract

The present invention provides a projection image display member which suppresses deterioration of visibility due to a boundary line between a light-reflecting material portion and a portion having no light-reflecting material, and thus presents a great visual quality. This projection image display member has a configuration in which a light-reflecting material is laminated on at least a portion of a transparent hard material. A cross section taken in the thickness direction at a midpoint on each side of the light-reflecting material has an angle α of 60° to 120°, the angle being formed by a straight line derived from the surface opposite to the surface facing the transparent hard material and a straight line adjacent to said straight line.

Description

Projected image display member, transparent display system, head-up display system, manned transportation, and screen

[0001] The present invention relates to a projection image display member that has good appearance, and to a transparent display system, a head-up display system, a manned transportation system, and a screen that use the same.

[0002] A projection image display component is a component that displays an image by reflecting light projected from a video projector and bringing the reflected image into the user's field of view. Examples of the use of projection image display components include head-up display systems that are mounted on the windshield of manned transportation vehicles and display route information, warning information, building information, etc. that are tailored to the scenery ahead of the passenger.

[0003] A known configuration of a projection image display component is one in which a light-reflective material is provided in a portion of a transparent windshield. Patent Document 1 discloses a nanofilm containing a dielectric layer and a metal layer as an example of a light-reflective material. While a configuration in which such a nanofilm is provided in a portion of the windshield provides excellent light reflectivity in the nanofilm portion, there is a difference in reflectivity between the nanofilm portion and the portion without the nanofilm, in other words, a color difference due to color tone and brightness, resulting in a noticeable boundary between the two. Furthermore, when a driver focuses their gaze on the scenery outside the windshield, which is located further back than the nanofilm, they may not be able to focus on this boundary, resulting in an annoying double image.

[0004] In consideration of these problems, Patent Document 2 shows an example in which a material (for example, a polarized reflective film) that exhibits higher transparency than the above-mentioned nanofilm is provided as a light-reflecting material in part of the windshield.

[0005] Japan Special Table No. 2017-538141 Japanese Special Table No. 2006-512622

[0006] However, the polarized reflective film disclosed in Patent Document 2 has a problem in that the edges become white when it is cut to a desired size. Therefore, when the method of Patent Document 2 is used, the boundary line caused by the difference in reflectance resulting from the presence or absence of the polarized reflective film, which is a light-reflecting material, becomes less noticeable, but visibility deteriorates due to the boundary line caused by whitening caused by cutting the polarized reflective film.

[0007] Therefore, the present invention aims to provide a projection image display component that has a good appearance by suppressing the whitening of the edges of the light-reflecting material and suppressing the deterioration of visibility due to the boundary between the light-reflecting material part and the part without the light-reflecting material.

[0008] The present invention aims to solve the above-mentioned problems and comprises the following configuration: A projection image display member having a configuration in which a light-reflecting material is laminated on at least a portion of a transparent hard material, wherein, in a cross section in the thickness direction at the midpoint of each side of the light-reflecting material, an angle α formed between a straight line originating from a surface opposite to a surface facing the transparent hard material and a straight line adjacent to the straight line is 60° or more and 120° or less.

[0009] The present invention can suppress whitening of the edges of the light-reflecting material, thereby suppressing deterioration of visibility due to the boundary between the light-reflecting material part and the part without light-reflecting material, and can provide a projection image display component with good appearance.

[0010] Fig. 1 is a schematic diagram illustrating one embodiment of the projection image display member of the present invention. Fig. 2 is an example of a cross-sectional image in the thickness direction of a light-reflecting material portion of the projection image display member. Fig. 3 is a supplementary diagram for explaining a method for measuring the angle α. Fig. 4 is a schematic diagram illustrating one embodiment of the transparent display system of the present invention. Fig. 5 is a schematic diagram showing the angle of the cut surface of the light-reflecting material as seen by a driver in the transparent display system of the present invention.

[0011] The following describes embodiments of the present invention, but the present invention should not be construed as being limited to the embodiments including the following examples, and various modifications are naturally possible within the scope of the invention, as long as the object of the invention can be achieved and the gist of the invention is not deviated from. Note that in this specification, "mass" is synonymous with "weight."

[0012] The projection image display member of the present invention has a configuration in which a light-reflecting material is laminated on at least a part of a transparent hard material, and is characterized in that, in a cross section in the thickness direction at the midpoint of each side of the light-reflecting material, an angle α formed between a line originating from a surface opposite to a surface facing the transparent hard material and a line adjacent to the line originating from the surface facing the transparent hard material is 60° or more and 120° or less. The projection image display member of the present invention will be described in detail below.

[0013] The projection image display member of the present invention may be flat or curved. When the projection image display member is curved, the surface of the light-reflecting material that constitutes it is usually also curved. In such an embodiment, the angle of incidence is determined by regarding the tangent plane at the center of gravity of the light-reflecting material surface as the incident surface. Furthermore, whether the surface of the light-reflecting material is curved or flat, each parameter measured by irradiating a light beam onto the light-reflecting material surface is measured at the center of gravity of the light-reflecting material surface.

[0014] The projection image display member of the present invention has a configuration in which a light-reflecting material is laminated on at least a portion of a transparent hard material. A projection image display member is a member that allows the image displayed by reflecting light emitted from a video projector to be simultaneously viewed superimposed on a background landscape. Here, "a configuration in which a light-reflecting material is laminated on at least a portion of a transparent hard material" refers to a state in which a light-reflecting material is laminated on a portion or the entire surface of a transparent hard material, either directly or via another layer. Details of the transparent hard material and the light-reflecting material will be described later. Figure 1 shows a specific example of the projection image display member of the present invention, but this is one embodiment of the projection image display member of the present invention, and the projection image display member of the present invention is not limited to this embodiment. The projection image display member 1 of the present invention shown in Figure 1 has a configuration in which a light-reflecting material 2 is laminated on a transparent hard material 3 via an adhesive layer 4.

[0015] A transparent hard material refers to a material that is transparent and serves as a support for a projection image display member. In the present invention, "transparent" refers to an average transmittance of 50% or more for light in the visible light range (wavelength 400 to 700 nm) incident at an angle of 0° relative to the normal direction of the surface (details on how to determine transparency will be described later). Furthermore, "hard" refers to an ability to maintain shape even when a certain load is applied, specifically, a deformation amount of 1% or less in the load direction at 5 kgf.

[0016] Examples of materials that can be suitably used as the transparent hard material include glass and transparent resin substrates. The thickness of the transparent hard material is preferably 1 mm or more and 10 mm or less from the viewpoints of supportability and suppression of weight increase. When the transparent hard material has a thickness of 1 mm or more, it becomes easy to maintain a strength sufficient to provide sufficient support. On the other hand, when the thickness of the transparent hard material is 10 mm or less, unnecessary increase in the weight of the entire projection image display member can be reduced.

[0017] When glass is used as the transparent hard material, not only single-layer glass but also laminated glass, tempered glass, plate glass, double-layer glass, vacuum glass, etc. Laminated glass and tempered glass are often used for automobile windshields, side windows, rear windows, etc., while plate glass, double-layer glass, and vacuum glass are often used for building materials, etc.

[0018] The resin substrate refers to a plate-like body in which resin accounts for 51% by mass or more and 100% by mass of all constituent components. Transparent resin substrates preferably used as transparent hard materials include those containing polyethylene terephthalate, polycarbonate, acrylic, polyvinyl chloride, polyethylene, polypropylene, polymethylpentene and copolymers thereof, acrylonitrile-butadiene-styrene copolymers, etc. Note that these transparent resin substrates may be composed of a single component or may contain multiple types of resins.

[0019] In the projection image display member of the present invention, in a thickness direction cross section at the midpoint of each side of the light-reflective material, the angle α between a line originating from the surface opposite the surface facing the transparent hard material and an adjacent line must be 60° or more and 120° or less. Here, "the line" refers to a line originating from one of the two main surfaces of the transparent hard material opposite the surface facing the transparent hard material. "In a thickness direction cross section at the midpoint of each side of the light-reflective material" means a thickness direction cross section at the midpoint of all sides of the light-reflective material. "A thickness direction cross section at the midpoint of the side of the light-reflective material" refers to a cross section of the light-reflective material portion when the projection image display member is cut along a plane perpendicular to the surface of the light-reflective material so as to include the midpoint of the side of the light-reflective material. "A midpoint of the side of the light-reflective material" refers to the midpoint of the side when the light-reflective material is observed from a direction perpendicular to the surface of the light-reflective material. For example, if the light-reflective material is a rectangular sheet, there will be four midpoints of the sides of the light-reflective material. In the following description, the "straight line originating from the surface opposite to the surface facing the transparent hard material" may be referred to as line X, and the "straight line adjacent to the line originating from the surface opposite to the surface facing the transparent hard material" may be referred to as line Y. In the above definition, when the projection image display member has a curved surface, the "light-reflecting material surface" may be interpreted as the tangent plane at the center of gravity of the light-reflecting material.

[0020] Next, we will explain the "midpoints of each side of the light-reflective material." It is preferable that the angle α be within the above range at all outer periphery points of the light-reflective material. However, since measuring all outer periphery points is extremely difficult, the midpoints of each side of the light-reflective material are selected as representative measurement positions. Generally, light-reflective materials are often rectangular, and the midpoints of each of the four sides are often used as measurement points. However, in cases where the light-reflective material has rounded corners or recessed sides, and is not strictly a quadrilateral but is a quadrilateral when observed macroscopically, a quadrilateral that includes the projection image display member and has the smallest area can be drawn, and the intersections of the lines connecting the opposing midpoints of the quadrilateral and the periphery can be used as midpoints. Note that a similar interpretation can be applied to polygons other than quadrilaterals. Furthermore, if the projection image display member is curved rather than flat, the midpoints can be determined by taking a point (point C) corresponding to the center of gravity of the light-reflective material, projecting the light-reflective material onto the tangent surface from a direction perpendicular to point C, identifying the midpoint on the projection surface, and identifying which part of the light-reflective material corresponds to the midpoint. In addition, if the light-reflecting material is not strictly a quadrilateral but is a quadrilateral (or other polygon) when observed macroscopically and has a curved surface, the midpoints of each side of the light-reflecting material can be determined by combining the above two methods.

[0021] A light-reflecting material cut to a desired shape and size has a surface on the transparent hard material side (a first surface facing the transparent hard material), a surface opposite the transparent hard material (a second surface facing the first surface; in a transparent display system, this is the surface onto which light from an image projector is irradiated), and a surface resulting from cutting (an end surface connecting the first and second surfaces; hereinafter, this may be referred to as a cut surface). If this light-reflecting material is cut at the midpoint of each side and an image of the cross section in the thickness direction is taken, an image such as that shown in Figure 2 can be obtained. Note that a cross-sectional image in the thickness direction can be obtained by observing the edge of the light-reflecting material using a known microscope or the like.

[0022] The outline of the cross section of the light-reflecting material obtained in this way (excluding the part where the light-reflecting material is present but cut off due to the size of the image, as shown on the right side of Figure 2) is formed by the surface on the transparent hard material side, the surface opposite the transparent hard material, and the cut surface. The "straight line (straight line X) originating from the surface opposite the surface facing the transparent hard material" and the "straight line (straight line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material" can be defined based on these (the method for defining each line will be described later), and the angle α is determined by each of these straight lines.

[0023] The angle α is a factor that determines the shape of the cut surface of the light-reflecting material. If the angle α is 90° or less, the cross-sectional shape of the light-reflecting material in the thickness direction, when observed with the transparent image display member side facing downward, will be a shape that expands upward or a shape that does not expand upward or downward. Therefore, when the light-reflecting material is viewed from the side opposite the transparent hard material, the cut surface (edge ​​surface) of the light-reflecting material will be hidden between the surface opposite the transparent hard material (second surface) and the transparent hard material, making it difficult to see. From the above perspective, the smaller the angle α, the better, but from the perspective of feasibility, the lower limit is 60°.

[0024] On the other hand, when the angle α exceeds 90°, the shape of the cross section of the light-reflective material in the thickness direction when observed in the same manner becomes wider at the bottom. Therefore, when the light-reflective material is viewed from the side opposite the transparent hard material, the cut surface is directly visible, and the edge of the light-reflective material is visible as a boundary. The appearance defect due to this mechanism becomes more easily visible as the angle α increases beyond 90°, and is particularly noticeable when the angle α exceeds 120°.

[0025] Considering the above, from the viewpoint of the appearance of the projection image display member, the upper limit of the angle α is 120°, preferably 100°, more preferably 95°, and particularly preferably 90°. On the other hand, the lower limit is 60°, preferably 70°, and more preferably 80°. In the projection image display member of the present invention, the values ​​of the angles α may be equal to or different from each other as long as they are all between 60° and 120°. The preferred upper and lower limits of the angle α can be interpreted in the same way.

[0026] To set the angle α between 60° and 120°, it is preferable to adjust the cutting method and conditions of the light-reflecting material, as described in detail below. To cut the light-reflecting material so that the angle α is between 60° and 120°, methods such as punching using a blade such as a Thomson blade, or using a cutter such as a round blade or a countersunk blade, laser light, or water pressure can be used. In particular, from the perspective of mass production, which allows for easy cutting into the desired shape in one cut, punching using a blade such as a Thomson blade is preferred. To set the angle α between 60° and 120°, it is effective to optimize the shape of the blade used for cutting and the surface where the blade is inserted during cutting. Below, a punching method using a Thomson blade is described in more detail. However, the punching and cutting methods should not be interpreted as being limited to those using a Thomson blade. Naturally, other punching and cutting methods can be adopted as long as they achieve the objectives of the present invention and do not deviate from the spirit and scope of the invention.

[0027] First, the blade shape can be symmetrical, such as a double-edged blade, or asymmetrical, such as a single-edged blade or a double-edged blade. However, considering the thickness of the light-reflecting material, it is preferable to use a double-edged blade. The blade angle of a double-edged blade is generally 26° to 55°, and preferably 26° to 42°. Generally, the smaller the blade angle, the sharper the blade. The larger the blade angle, the more oblique the cutting surface will be, and the smaller the blade angle, the more likely it is to cut at an angle closer to perpendicular. Therefore, the angle α can be adjusted by adjusting the blade angle of the blade used.

[0028] Next, we will explain the surface on which the blade is inserted. Cutting of the light-reflective material (projection image display member) may be performed from either side as long as the effects of the present invention are not impaired. However, when the light-reflective material has a protective layer on one side and an adhesive layer on the opposite side, as described below, it is preferable to insert the blade from the adhesive layer side in order to adjust the angle α within a suitable range and reduce cracking of the protective layer. Typically, the protective layer protects the reflective portion of the light-reflective material (the alternating laminated portion in the case of a laminate film, as described below) from external impact, and is therefore positioned on the side opposite the transparent hard material (the side viewed by humans when used as a transparent display system). Therefore, by inserting the blade on the adhesive layer side, the angle α of the light-reflective material can be easily reduced. Another advantage of inserting the blade on the adhesive layer side is that the blade does not come into direct contact with the protective layer of the light-reflective material, thereby reducing stress on the protective layer. These advantages reduce microcracks in the protective layer that occur during cutting, and also reduce whitening of the edges of the light-reflective material due to light scattering caused by fragments adhering to the adhesive layer.

[0029] Furthermore, when cutting a light-reflecting material (projection image display member), a heater may be connected to the blade during cutting if necessary, but it is preferable not to heat the blade because the contact of the heated blade will cause the light-reflecting material to melt and increase the angle α. The change in angle α due to this mechanism is significant when a light-reflecting material that melts easily is used.

[0030] A thickness direction cross-sectional image of a light-reflective material is typically obtained by photographing it at a magnification too high to be observed with the naked eye. Furthermore, because stress is applied to the light-reflective material during cutting, the thickness direction cross-sectional image often shows distortions, irregularities, and small deformations around the seams between the surfaces, resulting in a lack of strict straight lines. Therefore, it is difficult to accurately measure the angle between the surface of the transparent hard material and the cut surface. In the projection image display member of the present invention, lines X and Y are identified from the thickness direction cross-sectional image using the following procedure. The procedure is described below with reference to Figures 2 and 3.

[0031] 2 is an example of a thickness direction cross-sectional image of the light-reflecting material portion of the projection image display member, and FIG. 3 is a supplementary diagram for explaining a method for measuring the angle α (hereinafter, the thickness direction cross-sectional image of the light-reflecting material portion of the projection image display member may be simply referred to as a "cross-sectional image"). In FIG. 3, reference numerals 5 to 16 respectively represent the cross-sectional image after binarization processing (reference numeral 5), approximate line a (reference numeral 6), approximate line b (reference numeral 7), the perpendicular line between approximate lines a and b (reference numeral 8), approximate line c (reference numeral 9), approximate line d (reference numeral 10), approximate line e (the line (line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material, reference numeral 11), point 1 (reference numeral 12), point 2 (reference numeral 13), point 3 (reference numeral 14), point 4 (reference numeral 15), and approximate line f (the line (line X) originating from the surface opposite the surface facing the transparent hard material, reference numeral 16).

[0032] [1] A cross-sectional image of the light-reflecting material portion is binarized using image analysis software (a histogram of the image brightness is collected, and portions with a brightness less than the mode value are designated as black regions (0% brightness), and portions with a brightness equal to or greater than the mode value are designated as white regions (100% brightness)), and a cross-sectional image 5 after binarization is obtained. The line on the surface of the light-reflecting material facing the transparent hard material (hereinafter sometimes referred to as the underside) is approximated to a straight line (the resulting straight line is designated as approximated line a (reference numeral 6 in FIG. 3)). The image analysis software used for the binarization process is not particularly limited as long as it is capable of the above-mentioned binarization process, and can be appropriately selected from known software. For example, "Image-Pro" 10 (Media Cybernetics) or the like can be used. The approximation to a straight line is performed by dividing the line connecting both ends of the lower surface line into 10 equal parts, obtaining 9 points, and then selecting the nearest point on the lower surface line.Then, these 9 points and the points at both ends are used to find a total of 11 points, and the least squares method is used (hereinafter, the least squares method will be interpreted in the same way).

[0033] [2] In the cross-sectional image 5 after binarization processing, a line (approximate line b (reference numeral 7 in FIG. 3)) parallel to the approximate line a is drawn so as to be tangent to a line on the surface of the light-reflecting material opposite the surface facing the transparent hard material (hereinafter, sometimes referred to as the top surface), and a line (perpendicular line between approximate lines a and b (reference numeral 8 in FIG. 3)) perpendicular to both lines a and b is drawn so that the approximate lines a and b are the end points. Points are taken to divide this perpendicular line into 10 equal parts, and a line (approximate line c (reference numeral 9 in FIG. 3)) passing through the point closest to the approximate line a and parallel to the approximate line a, and a line (approximate line d (reference numeral 10 in FIG. 3)) passing through the point closest to the approximate line b and parallel to the approximate line a are drawn.

[0034] [3] In the section of the cut surface between the approximate lines c and d, the line obtained by approximating the cut surface to a straight line using the least squares method in the same manner as in [1] is called the approximate line e (reference numeral 11 in Figure 3). This approximate line e is the "straight line (line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material."

[0035] [4] The intersection of the approximate lines d and e is identified, and a point (point 1 (reference number 12 in Figure 3)) shifted inward (opposite the cut surface) from the intersection by the length of the approximate line e is determined on the approximate line d, and a point (point 2 (reference number 13 in Figure 3)) further shifted by 1.5 times the length of the approximate line e is determined. Lines perpendicular to the approximate line d are drawn from points 1 and 2 toward the top surface, and the intersections of these lines with the top surface are designated points 3 (reference number 14 in Figure 3) and 4 (reference number 15 in Figure 3), respectively.

[0036] [5] In the section between points 3 and 4, the line on the top surface of the section is approximated to a straight line by the least squares method in the same way as in [1], and this is designated as approximated line f (reference numeral 16 in FIG. 3). This approximated line f becomes the "straight line (line X) originating from the surface opposite to the surface facing the transparent hard material."

[0037] By following the steps [1] to [5] above, it is possible to measure the angle between the top surface and the cut surface caused by the cross-sectional shape of the light-reflecting material, even if there are irregularities or distortions on the top and bottom surfaces or the cut surface.

[0038] In the projection image display member of the present invention, the light-reflecting material serves to reflect light emitted from an image projector, thereby enabling the image to be viewed. For example, when the projection image display member of the present invention is used in a transparent display system, which will be described later, by positioning the projection image display member so that light from the image projector is irradiated onto the light-reflecting material, the viewer can view the image more clearly. Preferred embodiments of the light-reflecting material will be described later.

[0039] The projection image display member of the present invention preferably has an average reflectance of 10% to 60% in the wavelength range of 400 to 700 nm when P waves are incident on the surface of the light-reflecting material at an incident angle of 60°. The incident angle refers to the angle between the normal to the surface of the light-reflecting material and the direction of travel of the P waves. The normal to the surface of the light-reflecting material is a perpendicular line drawn to the surface of the light-reflecting material when the surface is flat, but when the surface of the light-reflecting material is curved, it is a perpendicular line drawn to the tangent plane at the center of gravity. Furthermore, when the surface of the light-reflecting material is curved, the incident angle is defined as above, and therefore the average reflectance is measured with the center of gravity of the surface of the light-reflecting material as the point of incidence of the P waves. The average reflectance can be calculated from the reflection spectrum obtained by measuring the reflectance of P waves at wavelength intervals of 1 nm using a spectrophotometer (details of the measurement method will be described later).

[0040] 60° is an example of the incident angle of light when projecting an image onto a projection image display member. When P-waves are incident on the surface of a light-reflecting material at an incident angle of 60°, if the average reflectance at wavelengths of 400 to 700 nm is 10% or more, the light irradiated onto the surface of the light-reflecting material is reflected, making it possible to display a visible image with sufficient brightness. On the other hand, while the image display performance improves as the reflectance increases, if the reflectance exceeds 60%, the light-reflecting material becomes too glare and conspicuous, and the background becomes difficult to see through the light-reflecting material due to a decrease in the transmittance of light projecting the background, thereby affecting the appearance of the projection image display member. From the above perspectives, the upper limit of the average reflectance is preferably 60%, more preferably 50%. From the viewpoint of achieving both image display performance and appearance of the projection image display member, the average reflectance is more preferably 15% to 50%, and particularly preferably 20% to 35%.

[0041] Hereinafter, a laminated film will be specifically described as an example of a material that can be suitably used as the light-reflecting material of the projection image display member of the present invention.

[0042] In the laminate film of the present invention, the light-reflecting material is preferably a laminate film having a configuration in which two or more different thermoplastic resin layers are regularly laminated in a number of 51 to 10,001 layers. Here, "different thermoplastic resin layers" means that they have different compositions and a refractive index that differs by 0.01 or more in any of the orientation axis direction, the direction perpendicular to the orientation axis in the film plane, and the direction perpendicular to the film plane.

[0043] "Different compositions" means that the components constituting the thermoplastic resin layer differ by 1% by mass or more, preferably by a different main component. A main component refers to a component that accounts for more than 50% by mass but not more than 100% by mass, when all components constituting the layer are taken as 100% by mass. The orientation axis direction refers to the direction in the film plane with the highest refractive index. The orientation axis direction can be measured using a known molecular orientation meter, and examples of measuring devices that can be used include the Molecular Orientation Meter MOA-8000 manufactured by Oji Instruments Co., Ltd. The refractive index in each direction of the outermost layer can be measured by the critical angle method using a laser with a wavelength of 633 nm, and examples of measuring devices that can be used include a known Abbe refractometer or a Prism Coupler SPA-400 manufactured by Cylon Technology Co., Ltd. The details of the measurement method when using the Prism Coupler SPA-400 manufactured by Cylon Technology Co., Ltd. will be described later.

[0044] The refractive index in each direction of layers other than the outermost layer can be measured by optical simulation using the thickness of each layer constituting the laminate film and the refractive index in each direction of the outermost layer measured by the above method. The thickness of each layer constituting the laminate film can be measured by cutting the laminate film parallel to the thickness direction using a microtome to obtain a cross-section sample, and observing the cross-section using a transmission electron microscope (TEM), such as the H-7100FA model (manufactured by Hitachi, Ltd.). Optical simulation can be performed using a VBA program using the optical thin film characteristic matrix method (Mitsunobu Kohiyama (2006). Optical Thin Film Filter Design, Optronics Co., Ltd.). Details of the thickness measurement of each layer and the optical simulation will be described later.

[0045] Furthermore, "regularly laminated" means that a plurality of different thermoplastic resin layers are laminated in a regular arrangement in the thickness direction. For the purpose of simplifying the explanation, some of the explanations will be given using as an example a laminate film having a configuration in which two different thermoplastic resin layers are alternately laminated, which is one of the preferred embodiments of the light-reflecting material for the transparent display system of the present invention. However, the same should be understood when three or more thermoplastic resin layers are used.

[0046] As a specific example of such an embodiment, when the laminated film is composed of a layer (layer A) mainly composed of a first thermoplastic resin and a layer (layer B) mainly composed of a second thermoplastic resin, A(BA) ｎ , B(AB) ｎ (n is a natural number representing the number of repeating units, the same applies hereinafter.) In addition, when the laminated film is composed of Layer A, Layer B, and a layer (Layer C) containing a third thermoplastic resin as the main component, the arrangement thereof is not particularly limited, but for example, C(BA) ｎ C and C (ABC) ｎ , C(ACBC) ｎBy alternately laminating a plurality of different thermoplastic resin layers in this way, it becomes possible to realize interference reflection that selectively reflects light in a desired wavelength band due to the relationship between the difference in refractive index in the in-plane direction of each layer, the difference in refractive index in the thickness direction, and the layer thickness.

[0047] The more layers there are and the more varied the thicknesses of the layers constituting the regular arrangement, the higher the reflectivity of light in a wider wavelength band that can be achieved with interference reflection. From the viewpoint of sufficiently reflecting light in the desired wavelength band, the number of layers in the laminate film is preferably 51 or more. Furthermore, a laminate film with 51 or more layers broadens the reflected wavelength band, enabling even reflection of visible light in the 400-700 nm range, and the color tone of the reflected light approaches colorless. Therefore, a projection image display component using such a laminate film as a light-reflecting material can reflect projected light from a video projector without a shift in color tone. As will be described in more detail below, a projection image display component using such a laminate film also has the advantage of reducing the color difference between the transparent hard material and the light-reflecting material, making the boundary between areas with and without the light-reflecting material less noticeable. From this viewpoint, the number of layers in the laminate film is more preferably 201 or more, and even more preferably 401 or more. Although there is no upper limit to the number of layers in a laminate film, as the number of layers increases, the manufacturing cost increases due to the need for larger manufacturing equipment, and the handling becomes worse as the thickness of the laminate film increases. Therefore, in reality, the practical range is 10,001 layers, and preferably 2,001 layers.

[0048] To achieve an average reflectance of 10% to 60% when P waves are incident on the light-reflecting material surface at an incident angle of 60°, a laminate film having the above-described laminate structure and adjusted refractive index differences between the two thermoplastic resin layers in the direction parallel to the film surface (in-plane direction) and the direction perpendicular to the film surface (plane-perpendicular direction) can be used. More specifically, a laminate film having a refractive index difference in the in-plane direction of 0.001 to 0.05 and a refractive index difference in the plane-perpendicular direction of 0.03 to 0.13 is preferably used, with a more preferred refractive index difference in the plane-perpendicular direction of 0.06 to 0.11. When three or more types of thermoplastic resin layers are regularly laminated, the refractive index difference in the plane-perpendicular direction calculated using the values ​​of the layer with the highest refractive index and the layer with the lowest refractive index is preferably within the above range. In addition, increasing the number of layers of the light-reflecting material or adjusting the layer thickness distribution of the laminated components can also increase the reflection intensity and broaden the reflection band, which is effective in increasing the average reflectance. By appropriately combining these methods as necessary, the average reflectance can be set within a desired range.

[0049] In order to make the interface between the areas where the light-reflecting material is present and the areas where it is not present less noticeable, the projection image display member of the present invention preferably has an average transmittance of 50% or more and 100% or less for wavelengths of 400 to 700 nm when light is incident on the light-reflecting material surface at an incident angle of 0°. The "light" referred to here does not refer to light that vibrates only in a specific direction, such as P waves or S waves, but rather to so-called natural light (note that such light is sometimes referred to as "unpolarized"). The wavelength band of 400 to 700 nm corresponds to the visible light range. By having an average transmittance of 50% or more and 100% or less in this band when light is incident on the light-reflecting material surface at an incident angle of 0°, the difference in transmittance between the transparent hard material and a transparent hard material having an average transmittance of 50% or more and 100% or less is clearly reduced, in accordance with the definition of "transparent." This makes the boundary between the transparent hard material and the light-reflecting material less noticeable, improving the appearance of the projection image display member.

[0050] The average reflectance is determined from the transmittance of light at each wavelength measured in 1 nm increments. The transmittance at each wavelength can be measured using a known spectrophotometer, and the measurement device can be, for example, a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd. Details of the measurement method, conditions, etc. will be described later.

[0051] From the above viewpoints, the average transmittance is preferably 70% to 100%, more preferably 80% to 100%, and particularly preferably 90% to 100%. To obtain such a projection image display member, it is effective to use a laminate film having the aforementioned laminate structure as the light-reflecting material constituting the projection image display member and to reduce the difference in refractive index (in-plane refractive index) between the two thermoplastic resin layers alternately laminated in the laminate film in a direction parallel to the film surface. Here, the in-plane refractive index refers to the average value of the refractive index in the orientation axis direction and the refractive index in the direction perpendicular to the orientation axis direction in the film plane. If the in-plane refractive index difference between the two thermoplastic resin layers is 0.05 or less, the average transmittance can be easily increased to 50% or more; if it is 0.04 or less, the average transmittance can be increased to 70% or more; if it is 0.03 or less, the average transmittance can be increased to 80% or more; and if it is 0.02 or less, the average transmittance can be increased to 90% or more. Furthermore, when a laminate film is used as a light-reflecting material, the average transmittance can also be increased by reducing the number of layers.

[0052] In the projection image display member of the present invention, it is preferable that the color difference between the area where the light-reflecting material is not present and the area where the light-reflecting material and the transparent hard material are laminated is 0 to 20. Hereinafter, this color difference may be referred to as ΔE. Here, the color difference refers to the color difference calculated using the CIE 1976 color difference formula established by the International Commission on Illumination (CIE), and more specifically, L ＊ a ＊ b ＊ The color tone (L １ ＊ , a １ ＊ , b １ ＊ ) and the color tone (L ２ ＊ , a２ ＊ , b ２ ＊ That is, the color difference (ΔE) is expressed by the following formula (1):

[0053]

[0054] A small color difference (ΔE) means that there is a small difference in color tone between the area where the light-reflecting material is not present and the area where the light-reflecting material and the transparent hard material are laminated. If ΔE is 20 or less, the boundary between the two becomes less noticeable, and the appearance of the projection image display member is improved. From the above viewpoint, ΔE is preferably 10 or less, more preferably 9 or less, and particularly preferably 5 or less. From the above viewpoint, the smaller ΔE is the better, and the lower limit is theoretically 0, and in consideration of feasibility, 1 is preferable.

[0055] As a method for making ΔE 0 or more and 20 or less, the L ＊ It is preferable to make the difference between L ＊ Since ΔE is a value that is greatly dependent on the average transmittance in the wavelength range of 400 to 700 nm, it is preferable to reduce the average transmittance in the wavelength range of 400 to 700 nm of light incident at an incident angle of 0° at the location where the light-reflecting material and the transparent hard material are laminated, in other words, the average transmittance in the wavelength range of 400 to 700 nm of light incident on the light-reflecting material at an incident angle of 0°. Methods for increasing the average transmittance of the light-reflecting material are as described above. For example, to make ΔE 5 or less, it is effective to make the in-plane refractive index difference between the two thermoplastic resin layers 0.01 or less.

[0056] In addition, in order to reduce ΔE, a color tone indicating a ＊ , b ＊ It is also effective to reduce the difference between a and b. ＊ , b ＊ is small, so a of the light-reflecting material ＊ , b ＊By reducing this, the area where the light-reflecting materials are laminated becomes closer to colorless, and ΔE becomes smaller. For example, when the above-mentioned laminated film is used as the light-reflecting material, ΔE can be reduced by designing the layer thickness so that light in the wavelength range of 400 to 700 nm can be transmitted evenly. Note that when the transparent hard material contains an additive such as a heat ray absorber, which causes a color rather than colorlessness, it is possible to reduce ΔE not only by making the light-reflecting material closer to colorless, but also by designing the layer thickness so that the color becomes close to the color of the transparent hard material, or by applying a coating of that color to the light-reflecting material.

[0057] L ＊ , a ＊ , b ＊ The transmission spectrum of the projection image display member is measured at an incident angle of 0°, and the spectral distribution of the D65 light source under the D65 light source and the color matching function of the XYZ system are used to calculate the L ＊ , a ＊ , b ＊ Specifically, it is possible to calculate L using the transmittance of light incident at an angle of incidence of 0° in the wavelength range of 400 to 1600 nm, the spectral distribution of the D65 light source, and the color matching function of the XYZ system. ＊ , a ＊ , b ＊ A known spectrophotometer can be used to measure the transmittance, and a specific example is a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd. The details of the measurement method when using this device will be described later. ＊ , a ＊ , b ＊ Regarding (a), if the projection image display member is curved, the measurement shall be made at the center of gravity for both the light-reflecting material portion and other portions (however, in the latter case, if the center of gravity is covered with the light-reflecting material portion, such as in an embodiment where the light-reflecting material is in the center, the measurement may be made at any position, regardless of whether the projection image display member is flat or curved, excluding portions that have been intentionally colored in places that are not expected to be visible when in use, such as a top shade).

[0058] Furthermore, the projection image display member of the present invention preferably has a colored layer on at least a portion of the light-reflective material. The colored layer can absorb light transmitted through the windshield, making it easy to adjust the average transmittance in the visible light region. Here, the colored layer refers to a layer containing 0.1% by mass or more of a colorant among all components constituting the layer, preferably a layer formed by including a black colorant. The type of colorant is not particularly limited and can be appropriately selected from those that absorb light in the visible light region with wavelengths of 400 to 700 nm. By adjusting the type and amount of colorant and the thickness of the colored layer, the average transmittance in the visible light region can be adjusted as desired. Examples of colorants used in the colored layer include light-absorbing materials, such as carbon black, graphite, iron oxide, aniline black, black iron oxide, and coal tar naphtha. These components may also be used in combination as appropriate. In the projection image display member of the present invention, having a colored layer on at least a portion of the light-reflective material means that the colored layer is present on the surface of the light-reflective material.

[0059] The method for forming a colored layer on the surface of the light-reflective material preferably involves coating the surface of the light-reflective material, and specific examples include screen printing, offset printing, pad printing, relief printing, inkjet printing, and gravure printing. The colorant preferably contains at least one of aluminum oxide and titanium carbide. The colored layer may also function as an adhesive layer, and specifically, the surface of the light-reflective material may have an adhesive layer to which a colorant has been added.

[0060] From the perspective of image display clarity, the projection image display member of the present invention preferably has a colored layer on at least a portion of the light-reflective material, and exhibits an average transmittance of 0% to 30% for wavelengths of 400 to 700 nm when light is incident. Here, "when light is incident" refers to light incident on the portion where the colored layer is located at an incident angle of 0°. By setting the average transmittance for wavelengths of 400 to 700 nm when light is incident to 0% to 30%, the background through the image projection range becomes less visible, making it easier to display the image clearly. Since the lower the average transmittance, the greater the image clarity, so the average transmittance is more preferably 10% or less, and even more preferably 1% or less. The average visible light transmittance can be measured using a known spectrophotometer; details of the measurement method will be described later. The average transmittance for wavelengths of 400 to 700 nm when light is incident can be adjusted, for example, by adjusting the amount of colorant in the colored layer.

[0061] A light-reflective material with a colored layer on its surface can easily improve the clarity of image display simply by attaching it to at least a portion of a transparent windshield. While colored layers are typically provided inside the windshield, it is difficult to add a colored layer to an existing windshield. On the other hand, a light-reflective material with a colored layer on at least a portion of it can be simply attached to the windshield to easily achieve a clear image display that is less affected by the background.

[0062] The projection image display member of the present invention has a light-reflecting material colored layer that is in a state of being ... ＊ It is preferable that the value has at least a portion where it shows a positive gradient. ＊ The value indicates the brightness of the colored layer of the light-reflecting material, and the higher the brightness, the higher the L ＊ The value becomes larger. ＊ The value indicates a positive gradient, which means that the L value gradually increases from the center of the colored layer of the light-reflecting material toward the boundary with the transparent hard material. ＊ By adopting such an embodiment, there is no large difference in brightness between the colored layer and the transparent hard material, so the boundary between them is not noticeable and a good appearance can be obtained.

[0063] From the center of the colored layer of the light-reflecting material toward the boundary with the transparent hard material, L ＊ A preferred method for showing a positive gradient in the value is to form a colored layer by, for example, dot-like gradation printing. More specifically, the brightness can be gradually changed by reducing the size of the dots from the center of the colored layer to the boundary with the transparent hard material. Note that, because the brightness is high at the boundary between the light-reflecting material and the transparent hard material, i.e., the edge of the light-reflecting material, it is important to set the angle α to be between 60° and 120°.

[0064] A method for producing a laminate film suitable for use as a light-reflecting material for the projection image display member of the present invention will be described in detail below, taking as an example an embodiment in which two thermoplastic resin layers are alternately laminated, although the laminate film is not limited to those obtained by the following method.

[0065] The laminated film has a configuration in which a layer (Layer A) mainly composed of a first thermoplastic resin and a layer (Layer B) mainly composed of a second thermoplastic resin are alternately laminated, and it is preferable that the first thermoplastic resin is a crystalline polyester resin (preferably polyethylene terephthalate, polyethylene naphthalate, or the like) and the second thermoplastic resin is an amorphous polyester resin containing a structure derived from terephthalic acid or naphthalenedicarboxylic acid.

[0066] The "amorphous polyester resin containing a structure derived from terephthalic acid or naphthalenedicarboxylic acid" is preferably a polyester resin in which 60 mol% to 100 mol% of the dicarboxylic acid components constituting the polyester resin are terephthalic acid or / and naphthalenedicarboxylic acid. Furthermore, the basic skeletons of the first thermoplastic resin and the second thermoplastic resin are preferably the same from the viewpoint of interlayer adhesion, etc. Here, the "basic skeleton" refers to the repeating unit that is most abundant in the molecular chain of the thermoplastic resin in terms of mol%, and for example, in the case of polyethylene terephthalate, this corresponds to the ethylene terephthalate skeleton.

[0067] Crystalline resins are those obtained by heating a resin from 25 ° C. to 300 ° C. at a heating rate of 20 ° C. / min (1st RUN), maintaining the temperature at that temperature for 5 minutes, then rapidly cooling it with liquid nitrogen to 25 ° C. or less, and then heating it again from room temperature to 300 ° C. at a heating rate of 20 ° C. / min (2nd RUN). The heat of crystalline fusion ΔHm calculated from the peak area of ​​the melting peak in the differential scanning calorimetry chart obtained is a thermoplastic resin having a ΔHm of 5 J / g or more. On the other hand, amorphous resins are thermoplastic resins having a ΔHm of 5 J / g or less obtained by the above method, and more preferably, a thermoplastic resin that does not exhibit a peak corresponding to crystalline melting.

[0068] The first thermoplastic resin and the second thermoplastic resin may contain structural units derived from the following dicarboxylic acid component or diol component. Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfonedicarboxylic acid. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid, and ester derivatives thereof. These acid components may be used alone or in combination of two or more.

[0069] Examples of the diol component include ethylene glycol, paraxylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, spiroglycol, bisphenoxyethanolfluorene (BPEF), etc. These diol components may be used alone or in combination of two or more.

[0070] The laminated film can be produced by laminating thermoplastic resins, for example, by the following method. First, two types of thermoplastic resins (which are called thermoplastic resin compositions when they contain other components, but are referred to as thermoplastic resins) are prepared in the form of pellets or the like. The pellets are dried in hot air or under vacuum as needed, and then fed into separate extruders. The thermoplastic resins are heated and melted in the extruders at a temperature above their melting point, and the extrusion rate is made uniform using a gear pump or the like. After that, foreign matter, modified resins, etc. are removed from the molten thermoplastic resins through a filter or the like. Next, the two types of thermoplastic resins are fed into a multi-layer lamination device through separate flow paths and alternately laminated.

[0071] Multi-manifold dies, feed blocks, static mixers, and the like can be used as multi-layer lamination devices. In particular, from the viewpoint of achieving the desired number of layers, it is preferable to use a feed block having preferably 51 or more fine slits, more preferably 201 or more, and even more preferably 401 or more fine slits. The use of such a feed block prevents the device from becoming excessively large, reduces the amount of foreign matter caused by thermal degradation of the resin, and enables high-precision lamination even when the number of layers is extremely large. Furthermore, the lamination accuracy in the width direction is also significantly improved. Furthermore, with such a multi-layer lamination device, the thickness of each layer can be adjusted by the shape (length, width) of the slits, and the number of layers can be adjusted by the number of slits, making it easy to achieve any desired layer thickness or number of layers. When using such a feed block, the number of layers can be easily increased by increasing the number of slits. However, to avoid increasing the size of the device, the upper limit of the number of slits is preferably 10,001, and more preferably 2,001.

[0072] The laminated molten thermoplastic resin is then formed into a sheet using a die and extruded onto a cooling body such as a casting drum, where it is cooled and solidified to obtain a cast film. Preferably, the molten thermoplastic resin sheet is brought into close contact with the cooling body such as a casting drum by electrostatic force using a wire-, tape-, needle-, or knife-shaped electrode, whereby it is rapidly cooled and solidified. The temperature and rotation speed of the casting drum are not particularly limited as long as they are capable of cooling and solidifying the molten thermoplastic resin sheet, but a temperature of 20 to 40°C and a rotation speed of 1 to 5 m / min are preferred.

[0073] The cast film thus obtained is preferably biaxially stretched. Biaxial stretching refers to stretching in the longitudinal direction and the width direction. The longitudinal direction refers to the running direction of the film, and the width direction refers to the direction perpendicular to the longitudinal direction in the plane of the film. Biaxial stretching may be performed by sequentially stretching in two directions (sequential biaxial stretching) or by simultaneously stretching in two directions (simultaneous biaxial stretching). Furthermore, if necessary, further re-stretching may be performed in the longitudinal direction and / or the width direction. Sequential biaxial stretching will be described below.

[0074] In the case of sequential biaxial stretching, the longitudinal stretching speed is preferably 40 to 300% / sec, more preferably 50 to 150% / sec. Typically, longitudinal stretching (longitudinal stretching) is performed by the difference in peripheral speed between rolls, and the stretching ratio is preferably 1.5 to 5.0 times, more preferably 3.0 to 5.0 times, and even more preferably 3.3 to 5.0 times. The stretching temperature is preferably at least the glass transition temperature of the thermoplastic resin with the lower glass transition temperature among the first and second thermoplastic resins, but not more than a temperature 100°C higher than the glass transition temperature of the thermoplastic resin, and more preferably at least 3°C ​​higher than the glass transition temperature of the thermoplastic resin, but not more than a temperature 15°C higher than the glass transition temperature of the thermoplastic resin (however, the upper limit is set so as to be lower than the melting point of the resin with the lower glass transition temperature).

[0075] Subsequently, the uniaxially stretched film obtained by longitudinal stretching is preferably stretched in the width direction (transverse stretching) at a stretching speed of 4 to 40% / sec, more preferably 4 to 30% / sec, and even more preferably 5 to 20% / sec. Stretching in the width direction is usually carried out using a tenter, conveying the uniaxially stretched film while holding both widthwise ends with multiple clips, and the stretching ratio is preferably 1.5 to 6.5 times, more preferably 3.0 to 5.0 times, and even more preferably 3.4 to 5.0 times. Furthermore, the width direction stretching temperature is preferably 7 to 20°C higher than the longitudinal stretching temperature.

[0076] The sequentially biaxially stretched film is preferably heat-treated in a tenter at a temperature 50°C to 150°C higher than the stretching temperature, with a more preferred heat treatment temperature being 170°C to 230°C. The refractive index of Layer B of the laminate film can be controlled by conducting the heat treatment at an appropriate temperature depending on the types of first and second thermoplastic resins. Furthermore, a relaxation treatment in the width direction is preferably conducted in the latter half of the heat treatment, with the relaxation ratio being preferably 0.90 to 0.99 times (in other words, 1 to 10%) the width of the film immediately before relaxation. The laminate film thus obtained is then uniformly and slowly cooled to room temperature, after which the edge portions at both widthwise ends that were held by the tenter clips are cut and wound up. A roll of the laminate film can be obtained in this manner.

[0077] The projection image display member of the present invention preferably has a protective layer on the outermost surface facing the light-reflecting material. As described above, when the projection image display member is used in a transparent display system, the image display performance can be improved by arranging the projection image display member so that the light-reflecting material is the light incident surface. However, when a transparent display system is created by arranging the projection image display member in this manner, deterioration due to wear of the light-reflecting material and the resulting deterioration in image display performance can become an issue. The "outermost surface facing the light-reflecting material" refers to the outermost surface on the side of the transparent hard material where the light-reflecting material is located. Note that, when multiple transparent hard materials are present, the outermost surface facing the light-reflecting material is determined based on the transparent hard material closest to the light-reflecting material. If a layer primarily composed of an inorganic substance is present on the outermost surface facing the light-reflecting material, the layer is treated as not being present when identifying the protective layer.

[0078] By providing a protective layer on the outermost surface on the light-reflecting material side, the projection image display member maintains high image display performance while improving the abrasion resistance of the light-reflecting material. Here, the term "protective layer" refers to a layer in which, out of 100% by mass of all components constituting the layer, 40% by mass or more and 100% by mass or less, preferably 50% by mass or more and 100% by mass or less, is a thermosetting resin or an active energy ray-curable resin. When multiple such layers are present in succession from the outermost surface on the light-reflecting material side, these layers are treated as a single protective layer (i.e., the protective layer may have either a single-layer structure or a multilayer structure). When multiple types of thermosetting resins or active energy ray-curable resins are included, the amount of the thermosetting resins or active energy ray-curable resins is calculated by adding together all the types.

[0079] Below, a method for forming a protective layer on the outermost surface of the projection image display member on the light-reflecting material side will be explained using an example in which the above-mentioned laminated film is used as the light-reflecting material, but the method for forming a protective layer in the present invention is not limited to the embodiment described below.

[0080] First, a coating composition containing a desired solvent, binder component, photopolymerization initiator, inorganic particles, and other additives as needed is applied to the surface of the laminated film. Examples of coating methods that can be used include microgravure coating and die coating. It is also preferable to apply the coating uniformly without unevenness using a coating wire bar. In this method, the desired thickness can be easily adjusted by selecting a coating wire bar with an appropriate groove depth depending on the type and solids concentration of the coating composition.

[0081] Subsequently, it is preferable to volatilize the solvent from the coating composition in a drying step. Drying methods that can be used include heat transfer drying (contact with a hot object), convection heat transfer (hot air), radiation heat transfer (infrared rays), and other drying methods (microwaves, induction heating). The drying temperature, although it depends on the type of solvent in the coating composition, is preferably within the range of room temperature to 200°C, more preferably 60°C or higher and 200°C or lower, and even more preferably 80°C or higher and 150°C or lower.

[0082] Subsequently, the coating composition is dried to volatilize the solvent and then cured to form a protective layer. The curing method can be selected appropriately depending on the composition of the coating composition, etc. For example, if the resin of the coating composition is an active energy ray-curable resin, it is preferable to use a method of curing by irradiating with active energy rays. As the active energy ray, although it depends on the type of resin, ultraviolet (UV) or electron beams are preferred, and ultraviolet is more preferred (in other words, the active energy ray-curable resin contained in the coating composition is preferably one that is cured by UV or electron beams, and UV-curable resins are more preferred). The light source of the active energy ray irradiated to thicken the coating film is not particularly limited, but for example, if the resin of the coating composition is a UV-curable resin, a UV-LED lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, a xenon lamp, etc. can be used, and two or more of these may be used.

[0083] In the projection image display member of the present invention, the protective layer preferably has an inorganic particle concentration of 10% by mass or more and 60% by mass or less, from the viewpoint of achieving both processability and abrasion resistance. The inorganic particle concentration in the protective layer can be calculated as a value when all components constituting the protective layer are taken as 100% by mass. The protective layer can be formed, for example, by radically polymerizing an organic monomer such as acrylic through UV irradiation, thereby growing and curing polymer chains having crosslinking points. While the processability (shrinkage and flexibility) and abrasion resistance / hardness of the protective layer can be controlled by adjusting the monomer type and the amount of crosslinking points, these generally have a trade-off relationship and are difficult to achieve simultaneously. However, the inclusion of inorganic particles in the protective layer can improve abrasion resistance and hardness. Therefore, by adding inorganic particles to an organic protective layer that has excellent processability but poor hardness and abrasion resistance, it is possible to achieve both high processability, hardness, and abrasion resistance.

[0084] From this perspective, in the laminate film of the present invention, the concentration of inorganic particles in the protective layer is preferably 10% by mass or more and 60% by mass or less. When the concentration of inorganic particles in the protective layer is 10% by mass or more, the effect of improving hardness and abrasion resistance is good. Furthermore, usually, the higher the concentration of inorganic particles in the protective layer, the better the effect of improving hardness and abrasion resistance can be expected. However, if the concentration of inorganic particles in the protective layer exceeds 60% by mass, the hardness of the protective layer becomes too high, resulting in reduced processability, or the occurrence of scratches due to particle detachment during abrasion increases, which may conversely worsen abrasion resistance. From the above perspective, the concentration of inorganic particles contained in the protective layer is more preferably 20% by mass or more and 50% by mass or less.

[0085] In the projection image display member of the present invention, the inorganic particle occupancy rate of the outermost surface of the protective layer is preferably 0.1% or more and 60% or less. By adopting such an embodiment, high abrasion resistance can be imparted to the protective layer. Here, the inorganic particle occupancy rate refers to the area ratio of the inorganic particle portion occupying the outermost surface of the protective layer, and can be calculated using analysis software from images obtained by observing the surface with a SEM (details of the measurement method will be described later). The inorganic particle occupancy rate of the outermost surface of the protective layer increases as the number of inorganic particles present on the outermost surface of the protective layer increases.

[0086] When the inorganic particle occupancy rate on the outermost surface of the protective layer is 60% or less, the protective layer exhibits good abrasion resistance and is less susceptible to scratches. In a typical abrasion resistance test, a test piece (such as a cloth with a microscopically rough surface) is pressed against the protective layer and reciprocated hundreds to tens of thousands of times to evaluate the occurrence of scratches. Scratches on a protective layer containing inorganic particles are primarily caused by the surface of the test piece getting caught on particles present on the outermost surface of the protective layer, causing the particles to fall off and stress to concentrate at that point. Therefore, the lower the inorganic particle occupancy rate on the outermost surface of the protective layer, the more suppressed the test piece from getting caught on the particles, improving the abrasion resistance of the protective layer. From the above perspective, the inorganic particle occupancy rate on the outermost surface of the protective layer is preferably 50% or less. Furthermore, the lower limit of the inorganic particle occupancy rate on the outermost surface of the protective layer is 0.1% from the perspective of feasibility, given that the inorganic particle concentration in the protective layer must be at least 10% by mass, but is more preferably 10%. The inorganic particle occupancy rate on the outermost surface of the protective layer is typically proportional to the inorganic particle concentration in the protective layer and can be controlled by adjusting the inorganic particle concentration in the protective layer.

[0087] The inorganic particle component that can be used in the protective layer is preferably at least one selected from the group consisting of metals, semimetals, and their oxides, nitrides, borides, carbonates, and sulfates, and more preferably an oxide of at least one element selected from Si, Na, K, Ca, Mg, Ga, Zr, Ti, Al, In, Sb, Sn, and Ce. Specifically, silica (SiO ２ ), zirconium oxide (ZrO ２ ), titanium oxide (TiO ２ ), aluminum oxide (Al ２ O ３ ), indium oxide (In ２ O ３ ), zinc oxide (ZnO), tin oxide (SnO ２ ), antimony oxide (Sb ２ O ３ ), and indium tin oxide, etc. can be preferably used. These inorganic particles may be used alone or in combination of two or more kinds.

[0088] The projection image display member of the present invention preferably has a protective layer crack initiation pressure of 1 GPa or more and 200 GPa or less, as measured by a microscratch test method conforming to JIS R-3255:1997. The microscratch test method conforming to JIS R-3255:1997 is a method for quantifying hardness by contacting a stylus having a diameter of several to several tens of micrometers with the outermost surface of a test object, measuring the load applied to the stylus while increasing the load over time, and determining the point at which the load behavior changes abruptly when a scratch is made on the surface as the crack initiation pressure (the detailed measurement method will be described later). The device for measuring the crack initiation pressure is not particularly limited as long as it is capable of measurement, but a scratch tester (CSR5000 manufactured by Rhesca Corporation) or the like can be used. Hereinafter, the "crack initiation pressure of the protective layer obtained by the microscratch test method conforming to JIS R-3255:1997" may also be referred to as the "crack initiation pressure."

[0089] When the crack initiation pressure is 200 GPa or less, the protective layer on the outermost surface on the light-reflecting material side can have an appropriate hardness. When a light-reflecting material having such a protective layer is cut to the desired size, excessive stress is not applied to the edge portion of the protective layer, and microscale cracks and the associated whitening are suppressed. As a result, when a light-reflecting material having such a protective layer is used, the boundary between the transparent hard material and the light-reflecting material becomes less noticeable, improving the appearance of the projected image display member. From the above perspective, a crack initiation pressure of 190 GPa or less is more preferable.

[0090] On the other hand, by increasing the hardness of the protective layer to 1 GPa or more, the occurrence of scratches due to abrasion can be suppressed. For example, when a cloth or the like is pressed against the protective layer, the protective layer deforms along the cloth, causing stress concentration and resulting in scratches. However, by providing a protective layer with a hardness of 1 GPa or more, the occurrence of such abrasions can be reduced. Therefore, scratches that occur when the surface of the projection image display member facing the light-reflecting material is wiped with a cloth or the like can be reduced. From the above viewpoint, the crack occurrence pressure is more preferably 100 GPa or more, and even more preferably 145 GPa or more.

[0091] The cracking pressure of the protective layer can be adjusted by appropriately selecting the type and solids concentration of the coating composition, or by adjusting the concentration of inorganic particles that affect the hardness of the protective layer (it can be adjusted by appropriately combining them). More specifically, when the total mass of all components constituting the layer is taken as 100 mass%, the inorganic particle concentration contained in the protective layer can be set to 0.1 mass% to 80 mass%, preferably 11 mass% to 55 mass%, and more preferably 12 mass% to 25 mass%, thereby making it possible to set the cracking pressure to 1 GPa to 200 GPa or the above preferred range. Furthermore, since the cracking pressure is largely dependent on the type of monomer (binder component type) used to form the protective layer, which is a solid component, it can be controlled by appropriately selecting its type and concentration.

[0092] In the projection image display member of the present invention, the arithmetic mean roughness of the protective layer is preferably 0.10 nm or more and 0.90 nm or less. By adopting such an embodiment, even when rubbed with a rough cloth or the like, the surface of the protective layer is smooth and therefore less susceptible to scratches. From the above viewpoint, the lower the arithmetic mean roughness of the protective layer, the smoother the surface becomes, which is preferable, but from the viewpoint of feasibility, the lower limit is 0.10 nm. From the above viewpoint, the arithmetic mean roughness is more preferably 0.30 nm or more and 0.70 nm or less, even more preferably more than 0.55 nm and 0.70 nm or less, and particularly preferably 0.62 nm or more and 0.70 nm or less.

[0093] When the projection image display member has a protective layer, the proportion of inorganic particles in the outermost surface of the protective layer affects the arithmetic mean roughness of the outermost surface on the light incident side of the projection image display member, as described above. Therefore, in such an embodiment, in order to reduce the arithmetic mean roughness of the surface opposite to the light incident side, a method can be used that reduces the arithmetic mean roughness of the protective layer.

[0094] To reduce the arithmetic mean roughness of the protective layer, it is effective to reduce the particle concentration of the protective layer or the average particle diameter in the protective layer. More specifically, it is effective to set the particle amount in the protective layer to 0.1% by mass or more and 55% by mass or less, preferably 11% by mass or more and 55% by mass or less, and more preferably 12% by mass or more and 25% by mass or less, when all components constituting the layer are taken as 100% by mass, and to set the average particle diameter of the particles to 70 nm or less (preferably 60 nm or less). If the average particle diameter is larger than 70 nm, the particles are likely to fall off during wear of the protective layer, causing excessive stress at those locations and making scratches more likely. From the above perspectives, the average particle diameter of the particles is more preferably 60 nm or less, more preferably 30 nm or less. On the other hand, from the perspective of feasibility, the lower limit of the average particle diameter of the particles is 5 nm, and in reality, 10 nm is more preferable.

[0095] Furthermore, by forming a low refractive index layer, which will be described later, on the surface on the light reflecting material side, the arithmetic mean roughness of that surface can also be reduced.

[0096] The arithmetic mean roughness can be measured using a known scanning white light interference microscope, and the measuring device that can be used is, for example, the "VertScan" (registered trademark) VS1540 manufactured by Hitachi High-Tech Science Corporation (details of the measuring method when using this device will be described later).

[0097] The projection image display member of the present invention preferably includes at least one low-refractive index layer having a refractive index of 1.00 or more and 1.50 or less on the outermost surface facing the light-reflecting material. By providing the low-refractive index layer, the reversed phases of incident light and reflected light cancel each other out, suppressing reflection on the surface of the projection image display member. Therefore, this configuration can increase the light transmittance from the front, making the boundary line with the transparent hard material (e.g., glass) less noticeable and improving the visibility of the scenery through the light-reflecting material.

[0098] The low refractive index layer is made of silica (SiO ２Examples of suitable low-refractive-index layers include titanium nitride, magnesium fluoride, barium fluoride, calcium fluoride, hafnium fluoride, and lanthanum fluoride, which can be used alone or in appropriate combination. The method for providing a low-refractive-index layer on the outermost surface of a projection image display member is not particularly limited, and either a wet coating method or a dry coating method can be used, and can be appropriately selected depending on the material used for the low-refractive-index layer. Dry coating methods such as vacuum deposition, CVD, sputtering, and electron beam vapor deposition are also preferred because they can form thin films with a more uniform thickness. Among these, sputtering is preferred because it provides excellent uniformity in thickness and is easy to form dense films. In sputtering, for example, when the aforementioned laminate film is used as a light-reflecting material, a thin film can be continuously formed while the long laminate film is transported in one direction (longitudinal direction) using a roll-to-roll method, thereby improving productivity.

[0099] The projection image display member of the present invention preferably has an adhesive layer between the transparent hard material and the light-reflecting material. From the viewpoint of reducing peeling, the transparent hard material and the light-reflecting material are preferably bonded together via an adhesive layer such as a pressure-sensitive adhesive or adhesive. Examples of suitable pressure-sensitive adhesives and adhesives include vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinyl ether, nitrile rubbers, styrene-butadiene rubbers, natural rubbers, chloroprene rubbers, polyamides, epoxy resins, polyurethanes, acrylic resins, cellulose, polyvinyl chloride, polyacrylic esters, polyisobutylene, and silicone-based adhesives. Among these, silicone-based pressure-sensitive adhesives and adhesives are preferred. Examples of particularly suitable silicone-based pressure-sensitive adhesives include AS-PSA003 manufactured by Arakawa Chemical Industries, Ltd. and X-40-3270 manufactured by Shin-Etsu Chemical Co., Ltd. These pressure-sensitive adhesives and adhesives may be used alone or in combination, and may contain, in order to provide functionality, an adhesiveness adjuster, a plasticizer, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a colorant, a crosslinking agent, etc. In particular, by adding a colorant, the adhesive layer functions as a colored layer, which reduces the visibility of the background as described above and makes the displayed image easier to view.

[0100] These adhesives may be in liquid, gel, block, powder, film, or other forms before processing. Adhesive solidification methods include solvent evaporation, moisture curing, heat curing, curing agent mixing, anaerobic curing, ultraviolet curing, thermal melting and cooling, and pressure-sensitive curing. Lamination methods include water lamination, roller lamination, laminate molding, injection molding, vacuum molding, pressure molding, and combined vacuum and pressure molding. Projection image display components are produced by applying heat, pressure, and the aforementioned adhesive solidification methods. Water lamination is preferred due to the simplicity of the lamination method.

[0101] Furthermore, in the projection image display member of the present invention, the adhesive strength of the adhesive layer measured at a peel angle of 180° is preferably 0.01 N / 25 mm or more and 10.00 N / 25 mm or less, more preferably 0.01 N / 25 mm or more and 3.00 N / 25 mm or less. When laminating a light-reflecting material to a portion of a transparent hard material via an adhesive layer, handling errors and the like can cause air entrapment or distortion of the light-reflecting material. In anticipation of such cases, the light-reflecting material is required to be reworkable, allowing it to be peeled from the transparent hard material and re-laminate. If the adhesive strength is 10.00 N / 25 mm or less, the light-reflecting material can be easily peeled off even after being bonded to the transparent hard material, and problems such as adhesive residue associated with peeling can be alleviated. On the other hand, if the adhesive strength is 0.01 N / 25 mm or more, sufficient adhesive strength can be ensured for bonding the light-reflecting material to the transparent hard material. From the above perspective, the adhesive strength is more preferably 0.10 N / 25 mm or more and 10.00 N / 25 mm or less. As a method for setting the adhesive strength to 0.01 N / 25 mm or more and 10.00 N / 25 mm or less, it is effective to select an appropriate material for the adhesive layer, as described above. The adhesive strength can be measured by a method conforming to JIS Z 0237 (2009), the details of which will be described later.

[0102] A method for producing a projection image display member of the present invention will be described below using specific examples. However, the projection image display member of the present invention is not limited to those obtained by the method described below. For the projection image display member of the present invention, a laminate film having a structure in which two or more different thermoplastic resin layers are regularly stacked in 51 to 10,001 layers, and an adhesive layer is further laminated, is preferably used as the light-reflecting material. Such a light-reflecting material is preferably used by punching it into the desired shape using a Thomson blade and adjusting the blade direction. Next, water is applied to the adhesive layer surface with a spray bottle, and the laminate film is bonded to a transparent hard material. At this time, a thin flat plate or the like is pressed against the surface opposite the adhesive layer, and water is poured around the edge to remove any air bubbles or moisture trapped between the adhesive layer and the transparent hard material, thereby producing a projection image display member.

[0103] The transparent display system of the present invention is described below, and includes the projection image display member of the present invention and an image projector that irradiates the light-reflecting material in the projection image display member of the present invention with light containing 51% to 100% P-waves.

[0104] An example of such a transparent display system is shown in Fig. 4. In the transparent display system 17 shown in Fig. 4, light 19 that forms the source of an image (light for the image) is irradiated from an image projector 18 onto a projection image display member 1, and the image is projected onto the projection image display member 1. This allows an observer 20 of the transparent display system to view the image superimposed on a surrounding landscape 21. Note that reference numerals 22 and 23 in Fig. 4 denote the angle of incidence of the light for the image from the image projector to the projection image display member and the normal to the projection image display member.

[0105] It is important that the image from the image projector is an image using P waves in order to reduce overlapping images and achieve clear display when wearing polarized sunglasses. Here, an image using P waves refers to an image projected onto a projection image display member by light whose P wave intensity is greater than that of S waves being incident on the projection image display member. That is, it is important that the image projector in the transparent display system of the present invention emits light containing 51% to 100% P waves. Furthermore, P waves refer to electromagnetic waves whose electric field component is parallel to the plane of incidence (in other words, linearly polarized light oscillating parallel to the plane of incidence), and S waves refer to electromagnetic waves whose electric field component is perpendicular to the plane of incidence (in other words, linearly polarized light oscillating perpendicular to the plane of incidence).

[0106] When the light of the image incident on the projection image display member contains a large amount of S waves, the light that passes through the light reflecting material is reflected not only by the light reflecting surface of the projection image display member but also by the back surface of the transparent hard material, causing overlapping images to be visible. Since P waves have a lower reflectivity on the back surface of the transparent hard material than S waves, this configuration can reduce overlapping images. In particular, when P waves are incident on the projection image display member at an angle of incidence near the Brewster angle, overlapping images hardly occur.

[0107] Furthermore, by incorporating a large amount of P-wave components into the light from the image projector, it is possible to suppress a decrease in the brightness of the displayed image even when wearing polarized sunglasses. Polarized sunglasses are designed to block S-wave components to suppress glare from the ground and windshield, which are dominated by S-wave components when the ground or water surface is used as a reflective surface, and to ensure clear visibility. Therefore, by incorporating a large amount of P-waves, which have a polarization direction 90° different from S-waves, into the image light incident on the projected image display member, the brightness of the displayed image viewed by the viewer can be maintained even when wearing polarized sunglasses. From these perspectives, the higher the proportion of P-wave components in the image light irradiated onto the light-reflecting material surface, the better, preferably 90% or more, and even more preferably 99% or more. For the above reasons, there is no particular upper limit on the proportion of P-wave components in the image light incident on the projected image display member, and it can theoretically be 100%.

[0108] Methods for setting the proportion of P-wave components in the light of the image irradiated onto the surface of the light-reflecting material within this range include, for example, adjusting the polarization direction of the display inside the image projector, arranging a polarizing plate at the exit so that the transmission axis direction is parallel to the polarization direction of the P-wave, etc. It is also effective to use a light source with a high proportion of P-wave components.

[0109] Furthermore, it is preferable that the angle between the incident surface direction of light irradiated from the projection image display member of the present invention and the azimuth at which the P-wave reflectance of the light-reflective material is maximized is between 0° and 20°. A small angle between the incident surface direction of light irradiated from the image projector and the azimuth at which the P-wave reflectance of the light-reflective material is maximized can minimize the amount of light irradiated from the image projector, thereby efficiently obtaining a clear image display. This is also preferable from the viewpoint of suppressing the conversion of P-wave light transmitted through the light-reflective material to S-wave. Generally, light-reflective materials using biaxially stretched films have a phase difference and an orientation axis, and this orientation axis and the azimuth at which the P-wave reflectance is maximized coincide at an angle as close to 0° as possible. The larger the angle between the orientation axis and the polarization direction of the irradiated light, the greater the proportion of P-wave light converted to S-wave light, making overlapping images more visible, as described above. In view of the above, the angle between the directions at which the reflectance of the light-reflecting material for P waves is maximized is preferably as small as possible, more preferably 0° to 10°, and even more preferably 0° to 5°.

[0110] In the transparent display system of the present invention, when an image is projected at a single focus, a typical image projector such as a liquid crystal projector, an RGB laser, a DLP (Digital Light Processing), an LCOS (Liquid Crystal on Silicon), a liquid crystal, an organic EL (Electroluminescence), a micro LED (Light Emitting Diode), or a mini LED can be used. On the other hand, an image projector capable of multifocal display can also be used to simultaneously project images at different focuses to reduce the viewer's eye movement. In this case, a mirror reflection type image projector that combines a reflective mirror and a magnifying mirror separately from the light emitting device inside the image projector body, or a light guide type image projector that emits light from a light emitting device to a light guide member and converts the emission angle and emission range of the light beam before projecting it can be used. These image projectors can be freely selected taking into consideration the installation position, installation space capacity and installation angle, image projection position on the projection display member, brightness and color gamut of the image obtained, viewing angle, and the like.

[0111] In the transparent display system of the present invention, when the angle of incidence of light from the image projector is angle θ, it is preferable that the angles α and θ satisfy |180-(θ+α)|≧20. As shown in FIG. 5 , the angle (reference numeral 24) of the cut surface of the light-reflective material 2 relative to the normal when viewed from the driver (observer 20) in the transparent display system can be expressed as |180-(θ+α)|. As |180-(θ+α)| increases, the angle from the perpendicular to the cut surface increases, and the viewer 20 views the surface from an oblique direction, narrowing the range visible as the cut surface, making it difficult for the viewer 20 to recognize the boundary between areas with and without the light-reflective material 2. In other words, when |180-(θ+α)| is 20 or greater, the angle from the normal to the cut surface of the light-reflective material 2 increases, narrowing the area directly visible as the cut surface, making it difficult for the viewer 20 to recognize the edge of the light-reflective material 2 as a boundary. From the above perspective, it is preferable that |180 - (θ + α)| is large, more preferably 30 or greater, and even more preferably 36 or greater. One method for satisfying |180 - (θ + α)| ≥ 20 is to find an optimal combination of angle α (reference numeral 25 in FIG. 5) and angle θ (reference numeral 22 in FIG. 5). Note that the method for adjusting angle α is as described above, and angle θ can be adjusted by adjusting the position and angle of the image projector to match the traveling direction of the light from the image projector.

[0112] Note that a video projector typically irradiates light onto a surface of a certain extent, rather than onto a single point on a projection image display member. In such cases, the light incident direction is defined as the direction from the center of the video projector's light source toward the center of gravity of the light incident portion on the projection image display member. Furthermore, if the projection image display member is curved rather than flat, the incident surface is the tangent plane at the center of gravity.

[0113] The head-up display, manned transportation, and screen of the present invention will be described below. The head-up display of the present invention uses the transparent display system of the present invention. A head-up display is an image display device that enables a driver to simultaneously view the scenery outside the vehicle window while superimposing speed displays, navigation information, and the like. The transparent display system of the present invention is a transparent display system that combines image display capabilities and good appearance, and therefore can be suitably used for head-up displays that require such characteristics.

[0114] The manned transportation of the present invention is equipped with the transparent display system of the present invention or the head-up display of the present invention. Manned transportation refers to transportation means such as vehicles, trains, airplanes, and ships, both human-driven and unmanned with passengers. In such manned transportation, the driver is required to simultaneously view the scenery outside the vehicle window while superimposing speed displays, navigation information, and other information. Therefore, these requirements can be met by installing a transparent display system that combines image display capability and visual appeal, or a head-up display using such a transparent display system.

[0115] The screen of the present invention is made using the transparent display system of the present invention. Here, the screen is a system that combines a curtain for projecting and viewing an image with an image projector. The screen of the present invention has excellent image display properties and appearance, and can be used for spatial presentation in amusement applications, signage, show windows, and other electronic signage applications.

[0116] As described above, the present invention includes the following configurations <1> to <21>. <1> A projection image display member having a configuration in which a light-reflecting material is laminated on at least a portion of a transparent hard material, wherein, in a cross section in the thickness direction at the midpoint of each side of the light-reflecting material, the angle α between a line originating from the surface opposite to the surface facing the transparent hard material and a line adjacent to the line originating from the surface opposite to the surface facing the transparent hard material is 60° to 120°. <2> The projection image display member according to <1> above, wherein the average reflectance at wavelengths of 400 to 700 nm when P waves are incident on the light-reflecting material surface at an incident angle of 60° is 10% to 60%. <3> The projection image display member according to <1> or <2> above, wherein the average transmittance at wavelengths of 400 to 700 nm when light is incident on the light-reflecting material surface at an incident angle of 0° is 50% to 100%. <4> The projection image display member according to any one of <1> to <3> above, wherein the color difference between a portion where the light-reflecting material is not present and a portion where the light-reflecting material and the transparent hard material are laminated is from 0 to 20. <5> The projection image display member according to any one of <1> to <4> above, wherein at least a portion of the light-reflecting material has a colored layer, and when light is incident, the average transmittance of the light-reflecting material at a wavelength of 400 to 700 nm is from 0 to 30%. <6> The projection image display member according to any one of <1> to <4> above, wherein the color difference between a portion where the light-reflecting material is not present and a portion where the light-reflecting material and the transparent hard material are laminated is from 0 to 20. ＊The projection image display member according to <5> above, having at least a portion where the value shows a positive gradient. <7> The projection image display member according to any one of <1> to <6> above, wherein the light-reflecting material is a laminate film having a configuration in which two or more different types of thermoplastic resin layers are regularly laminated in 51 to 10,001 layers. <8> The projection image display member according to any one of <1> to <7> above, comprising a protective layer on the outermost surface on the side of the light-reflecting material. <9> The projection image display member according to <8> above, wherein the concentration of inorganic particles contained in the protective layer is 10% by mass or more and 60% by mass or less. <10> The projection image display member according to <8> or <9> above, wherein the inorganic particle occupancy rate on the outermost surface of the protective layer is 0.1% or more and 60% or less. <11> The projection image display member according to any one of <8> to <10> above, wherein the protective layer has a crack initiation pressure of 1 GPa or more and 200 GPa or less, as measured by a microscratch test method in accordance with JIS R-3255:1997. <12> The projection image display member according to any one of <8> to <11> above, wherein the protective layer has an arithmetic mean roughness of 0.10 nm or more and 0.90 nm or less. <13> The projection image display member according to any one of <1> to <7> above, comprising at least one low-refractive-index layer having a refractive index of 1.00 or more and 1.50 or less on the outermost surface on the side of the light-reflecting material. <14> The projection image display member according to any one of <1> to <13> above, comprising an adhesive layer between the transparent hard material and the light-reflecting material. <15> The projection image display member according to <14> above, wherein the adhesive strength of the adhesive layer to a glass surface measured at a peel angle of 180° is 0.01 N / 25 mm or more and 10.00 N / 25 mm or less. <16> A transparent display system comprising the projection image display member according to any one of <1> to <15> above, and a video projector that irradiates the light-reflecting material in the projection image display member with light containing 51% to 100% P-waves. <17> The transparent display system according to <16> above, wherein the angle between the incident surface direction of the light irradiated from the projection image display member and the orientation at which the P-wave reflectance of the light-reflecting material is maximized is 0° or more and 20° or less. <18> The transparent display system according to <16> or <17> above, wherein, when the angle of incidence of light from the video projector is angle θ, the angle α and the angle θ satisfy |180 - (θ + α)| ≧ 20.<19> A head-up display using the transparent display system according to any one of the above items <16> to <18>. <20> A manned transportation vehicle equipped with the transparent display system according to any one of the above items <16> to <18>. <21> A screen using the transparent display system according to any one of the above items <16> to <18>.

[0117] The projection image display member of the present invention and the laminate film used as the light-reflecting material thereof will be described below using examples. However, the projection image display member of the present invention and the laminate film used as the light-reflecting material thereof are not limited to the following embodiments.

[0118] [Methods for measuring physical properties and evaluating effects] The methods for evaluating physical properties and effects are as follows: Measurements were performed by irradiating light (including P waves and unpolarized light) at the center of gravity of the surface of the light reflecting material.

[0119] (1) Reflectance and Reflection Wavelength Band of P Waves at an Incident Angle of 60° A variable angle reflection unit and a Glan-Taylor polarizer were attached to a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd., and P waves were incident on the surface of the light-reflecting material at an incident angle of 60°, and the reflectance was measured in 1 nm increments. The average reflectance from 400 to 700 nm was determined from the obtained reflection spectrum. Furthermore, if the obtained reflection spectrum had a reflection band that was 10% or more continuously over 50 nm or more, the reflection wavelength band was defined as the interval between the minimum and maximum wavelengths of that reflection band. The measurement conditions were: slit: 2 nm (visible) / automatic control (infrared), gain: 2, and scanning speed: 600 nm / min.

[0120] (2) Light transmittance and color difference ΔE at an incident angle of 0° were determined by the following procedures (A) and (B). (A) A spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd. was equipped with only the attached angle variable reflection unit, and unpolarized light was incident on the laminated film surface (measurement specimen) at an incident angle of 0°, and the transmittance in the wavelength range of 400 to 1600 nm was measured in 1 nm increments. The measurement conditions were a slit of 2 nm (visible) / automatic control (infrared), a gain set to 2, and a scanning speed of 600 nm / min. The average transmittance in the range of 400 to 700 nm was determined from the obtained transmission spectrum. (B) Using the average transmittance determined in (A), the spectral distribution of the D65 light source, and the color matching function of the XYZ system, the L ＊ , a ＊ , b ＊ was calculated. ＊ a ＊ b ＊ The color tone of a point (any position) in the color space where there is no light-reflecting material is (L １ ＊ , a １ ＊ , b １ ＊ ), the color tone of the part where the light reflective material and the transparent hard material are laminated (L ２ ＊ , a ２ ＊ , b ２ ＊ ) and the color difference ΔE was calculated using the following formula (1).

[0121]

[0122] (3) Angle α The angle α was determined by the following steps [1] to [5]: identifying a line (line X) originating from the surface opposite the surface facing the transparent hard material and a line (line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material; measuring the angle between them, and defining this as angle α. The procedure will be described below with reference to Figure 3. In Figure 3, the symbols 5 to 16 respectively represent the cross-sectional image after binarization (symbol 5), approximate line a (symbol 6), approximate line b (symbol 7), the perpendicular line between approximate lines a and b (symbol 8), approximate line c (symbol 9), approximate line d (symbol 10), approximate line e (the line (line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material, symbol 11), point 1 (symbol 12), point 2 (symbol 13), point 3 (symbol 14), point 4 (symbol 15), and approximate line f (the line (line X) originating from the surface opposite the surface facing the transparent hard material, symbol 16).

[0123] [1] The cross-sectional image was binarized using image analysis software (a histogram of the image brightness was collected, and areas with a brightness less than the mode were designated as black (0% brightness), and areas with a brightness greater than the mode were designated as white (100% brightness)), and a cross-sectional image 5 after binarization was obtained. The line on the surface (lower surface) of the light-reflecting material facing the transparent hard material was approximated to a straight line (the resulting straight line was designated as approximated line a). For the binarization process, "Image-Pro" 10 (Media Cybernetics) was used as image analysis software. The approximation to the straight line was performed by dividing the line connecting both ends of the lower surface line into 10 equal parts to obtain 9 points, and then taking the nearest points on the lower surface line from each of these 9 points and the points at both ends, a total of 11 points. (The same applies to the least squares method below.) [2] In the cross-sectional image 5 after binarization, a line (approximate line b) parallel to the approximate line a was drawn so as to be tangent to the line on the surface (top surface) of the light-reflecting material opposite the surface facing the transparent hard material, and a line (perpendicular to the approximate lines a and b) perpendicular to both lines a and b was drawn so that the approximate lines a and b were the end points. Points were taken to divide this perpendicular line into 10 equal parts, and a line (approximate line c) passing through the point closest to the approximate line a and parallel to the approximate line a, and a line (approximate line d) passing through the point closest to the approximate line b and parallel to the approximate line a were drawn. [3] In the line of the cut surface in the section between the approximate lines c and d, the line obtained by approximating the line of the cut surface to a straight line using the least squares method in the same manner as in [1] was taken as the approximate line e. This approximate line e is the "straight line (line Y) adjacent to the line originating from the surface opposite the surface facing the transparent hard material." [4] The intersection of approximate lines d and e was identified, and a point (point 1) was determined on approximate line d, shifted inward (opposite the cut surface) from the intersection by the length of approximate line e, and a further point (point 2) was determined, shifted 1.5 times the length of approximate line e11. Lines perpendicular to approximate line d were drawn from points 1 and 2 toward the top surface, and the intersections of these lines with the top surface were designated points 3 and 4. [5] In the section between points 3 and 4, the line on the top surface in this section was approximated to a straight line using the least squares method, as in [1], and this was designated approximate line f. This approximate line f is the "straight line (line X) originating from the surface opposite the surface facing the transparent hard material."

[0124] (4) Number and thickness of layers of light-reflecting material (laminated film), thickness of surface layer (protective layer, low refractive index layer) A cross section perpendicular to the film surface was cut out using a microtome, and the number of layers in the laminate film, the thickness of each layer forming the laminate structure, and the thickness of the surface layer were confirmed by observing the sample using a transmission electron microscope (TEM). Photographs of the cross section were taken using a transmission electron microscope H-7100FA (manufactured by Hitachi, Ltd.) at an acceleration voltage of 75 kV. The thickness of each layer was measured using the microscope's length measurement function.

[0125] (5) Orientation axis of light-reflective material Using a retardation measuring device (KOBRA-21ADH) manufactured by Oji Scientific Instruments Co., Ltd., a light-reflective material (laminated film) cut to 3.5 cm x 3.5 cm was placed in the device, and the orientation axis direction in the film plane at an incident angle of 0° was measured.

[0126] (6) Refractive index of the outermost layer of the light-reflective material and the layer (layer A) including the outermost surface of the laminate film The refractive index of the light incident surface of the projection image display member and the outermost surface of the laminate film was measured using a prism coupler SPA-400 manufactured by Cylon Technology. The laser wavelength used for the measurement was 633 nm. The in-plane refractive index was determined by averaging the values ​​obtained for both outermost layers in the direction of the orientation axis and in the direction perpendicular to the orientation axis. The thickness refractive index was determined by averaging the values ​​obtained for both outermost layers in the direction of the orientation axis and in the direction perpendicular to the orientation axis. Among the multiple peaks indicating the refractive index obtained using the prism coupler, if there is a peak showing a refractive index in the in-plane direction of 1.52 or more, this is the refractive index of the layer (layer A) including the outermost surface of the alternating laminate component of the laminate film. If there is a peak showing a refractive index less than 1.52, this is the refractive index of the low refractive index layer or protective layer.

[0127] (7) Refractive index of Layer B of the laminate film Using the thickness of each layer of the laminate film obtained in (4) and the refractive index of the thermoplastic resin layer (Layer A) constituting the outermost surface, and setting the refractive index of each layer other than the outermost layer to an arbitrary value, an optical simulation of VBA program reflectance was performed using the characteristic matrix method of optical thin films (Mitsunobu Kohiyama (2006). Optical Thin Film Filter Design, Optronics Co., Ltd.). Next, from the optical simulation results and the reflectance measured by the measurement method described below, the average reflectance of a reflection band that is 10% or more continuously over 100 nm or more in the wavelength range of 400 to 2000 nm was calculated, and if the difference between the two was ±2% or less, that refractive index was taken as the refractive index of the layer (Layer B) other than the outermost layer.

[0128] (8) Surface Inorganic Particle Occupancy The inorganic particle occupancy on the surface of the light-reflective material was measured by the following procedures (A) to (E). (A) Using a scanning electron microscope (JEOL Field Emission Scanning Electron Microscope (FE-SEM) JSM-6700F), the outermost surface of the protective layer of the laminated film was observed at 50,000x magnification, and an image with a field of view of 1900 nm x 2500 nm was obtained. (B) The obtained image was imported into image analysis software "Image-Pro" 10 (Media Cybernetics), converted to 8-bit grayscale, and subjected to 7 x 7 low-pass image processing. (C) A brightness histogram of the processed image was taken, and the observed image was binarized, with areas below the mode brightness being black (0% brightness) and areas above the mode brightness being white (100% brightness). (D) Using the same image analysis software, the number of white areas is counted and the areas Sw and Nw of each white area are calculated. ２ The particle-occupied area Sw,total, which is the sum of the white regions, was calculated as follows: (E) The particle-occupied area Sw,total and the image field of view area Sfov (= 1900 × 2500 nm ２ The particle occupancy rate V was calculated from the above data by the formula (2): V = Sw, total × 100 / Sfov

[0129] (9) Arithmetic mean roughness: Measured according to the following procedures (A) to (C). (A) A projection image display member was cut out of the light-reflecting material to a size of 6 cm x 6 cm, and one of the two surfaces of the light-reflecting material, the surface opposite the transparent hard material, was measured using a scanning white light interference microscope (apparatus: Hitachi High-Tech Science Corporation's "VertScan" (registered trademark) VS1540). When the measurement sample was a projection image display member, a 50x objective lens was used, the measurement mode was set to WAVE mode, the measurement area was 113 μm x 113 μm, and the measurement Y axis was set to any one direction of the measurement sample, and the light incident surface of the projection image display member was measured in a 90° field of view. (B) The obtained microscopic image was subjected to image processing using the surface analysis software VS-Viewer Version 10.0.3.0 built into the microscope under the following image processing conditions. (Image processing conditions) Interpolation: Full interpolation Filtering: Median (3 x 3 pixels) Surface correction: Fourth order (C) For each measurement image that was processed under the above image processing conditions, "Height Parameters" was selected along with the following analysis conditions in the ISO parameter analysis within the surface analysis software, and the arithmetic mean height Sa obtained by outputting the obtained group of values ​​into the parameter sheet column was used as the arithmetic mean roughness of the measurement surface. The arithmetic mean roughness was calculated for 80 visual fields, excluding the five visual fields above and below each visual field, and the obtained average value was used.

[0130] (10) Crack Generation Pressure This was carried out by a micro-scratch test method in accordance with JIS R-3255:1997. Specifically, a 4 cm x 4 cm square projection image display member was prepared and placed on the measurement stage of a scratch tester (CSR5000 manufactured by Rhesca Co., Ltd.) with the light-reflecting material side facing the stylus side, and a surface scratch test was carried out under the following conditions: Stylus: Diamond stylus (stylus diameter 15 μm) Scratch speed: 10 μm / sec Excitation amplitude: 50 μm Excitation frequency: 45 Hz Touch detection level: 3.0 mN Load condition: Monotonically increasing (+1.33 mN / sec) Initial load: 0 mN Maximum load: 100 mN Measurement time: 600 seconds Measurement environment: 25°C, relative humidity 65%

[0131] The load at which the vertical sensor acceleration value (unitless) exceeded 200 for the first time during the time-dependent change from the start of measurement was defined as the crack initiation load. If the acceleration did not exceed 200 during the second measurement, the crack initiation pressure was defined as 800 mN. The crack initiation pressure was calculated from the obtained load and the diameter of the stylus using the following formula (3): Formula (3): Crack initiation pressure (GPa) = Crack initiation load (mN) ÷ (15 ÷ 2) ２ ÷π×1000

[0132] (11) Measurement of adhesive strength of adhesive layer The adhesive layer surface of a test piece cut to a length of 300 mm and a width of 25 mm was attached to a glass plate and then left to stand for 1 minute at 23°C and a relative humidity of 50%. The force required to peel these test pieces was measured as adhesive strength (N / 25 mm) using a universal testing machine manufactured by Orientec Co., Ltd. under conditions of a peel angle of 180° and a peel speed of 300 mm / min (in accordance with JIS Z 0237 (2009)).

[0133] (12) Proportion of P waves in light irradiated from an image projector to a light-reflecting material A polarizing plate was placed above the irradiation port through which light from the image projector was irradiated, with the transmission axis parallel to the incident surface, relative to the incident surface in a transparent display system composed of a projection image display member and an image projector, and the luminance of the irradiated image was directly measured using a color luminance meter BM-7AS manufactured by Topcon Technohouse Corp. Next, the polarizing plate was removed and the luminance of the irradiated image was directly projected in the same manner, and the ratio of these luminances was taken as the proportion of P waves in light irradiated from the image projector to the light-reflecting material.

[0134] (13) Angle between the incident surface direction of light irradiated from the projection image display member and the direction in which the reflectance of P waves of the light-reflective material is maximized Hitachi, Ltd. spectrophotometer (U-4100 Spectrophotometer) was equipped with an attached angle variable reflection unit and a Glan-Taylor polarizer, and the orientation axis direction of the light-reflective material in the projection image display member obtained in (5) was set to an azimuth angle of 0°, and rotated clockwise by 1° increments of 0° to 10° and counterclockwise by 1° increments of 1° to 10°. Under 19 conditions, the reflectance of P waves in the wavelength range of 400 to 700 nm at an incident angle θ = 60° was measured in 1 nm increments from each azimuth angle direction relative to the normal to the film surface. From the obtained reflectance, the azimuth angle direction in which the average reflectance of P waves in the wavelength range of 400 to 700 nm at an incident angle of 60° in each azimuth angle direction was maximized was determined as the direction in which the reflectance of P waves of the light-reflective material was maximized. The angle between this direction and the incident surface direction was measured using an angle measuring instrument manufactured by Shinwa Sokutei Co., Ltd., and this was taken as the angle between the incident surface direction of the light irradiated from the projection image display member and the direction in which the reflectivity of the P wave of the light-reflecting material is maximum.

[0135] (14) Preparation of Projection Image Display Members The laminate with the adhesive layer and protective layer laminated thereon was punched out with a Thomson blade having a blade angle as shown in Tables 4-1 to 4-4 to obtain a 9 cm square laminate. Water was then applied to the adhesive layer surface of the laminate with a spray bottle, and the laminate was bonded to a 10 cm square flat glass plate (transparent hard material) as shown in Tables 4-1 to 4-4. Next, a thin flat plate was pressed against the surface opposite the adhesive layer surface, and the water was allowed to flow to the edges to remove any air bubbles or moisture that had entered between the adhesive layer and the transparent hard material, thereby obtaining a projection image display member.

[0136] (15) Abrasion Resistance Test A test cloth was pressed against the light-reflecting material side surface (light incident surface) of the projection image display member prepared in (14), and rubbed under the following rubbing conditions. The occurrence of scratches was observed after a specified number of reciprocating strokes, and the number of times until at least one scratch occurred was determined. The minimum pass mark was no scratches after 1,000 strokes, and the more tests performed before scratches occurred, the better the abrasion resistance. <Rubbing Conditions> Test cloth: TT-STex (made of wool) manufactured by TRIBOTOUCH Displacement: 20 mm Movement speed: 50 mm / sec Pressing area: 6.5 mm x 6.5 mm Stress: 74 kPa Observation of scratch occurrence: every 100 strokes up to 1,000 strokes, every 1,000 strokes from 1,000 to 30,000 strokes, and every 5,000 strokes after 30,000 strokes.

[0137] (16) Displayability A transparent head-up display (HUD) system was prepared, equipped with the projection image display member prepared in (14) and an Apple iPad (registered trademark) 2 that generates and emits P waves as a projection light source, and the information displayability was evaluated visually when an image was projected at an incident angle of 60°. The evaluation criteria are as follows. <Evaluation criteria> A: The image projected onto the projection image display member was clearly visible down to the finest details. B: The image projected onto the projection image display member was inferior to the standard "A" but was fully visible. C: The image projected onto the projection image display member was less clear than the standard "B" but was slightly visible. D: The image was less clear than the standard "C" but was very slightly visible. Or, it was impossible to display an image.

[0138] (17) Double Image Visibility When an image was projected using the method in (16), the visibility of double images was visually evaluated. The evaluation criteria were as follows: <Evaluation Criteria> A: The image was clearly visible without any double images. B: The double images were visible if one looked closely, but the contrast ratio of the main image was high and did not affect visibility. C: The double images were visible even without looking closely, but were at a practically acceptable level. D: The double images were observed to an extent that was practically unacceptable.

[0139] (18) Conspicuousness of Boundaries (Caused by Whitening of Edges) The conspicuousness of boundaries due to whitening of edges of the light-reflecting material of the projection image display member was evaluated visually. The evaluation criteria are as follows: <Evaluation criteria> 5: No whitening of edges, and the boundary line was thin and therefore not noticeable. 4: Almost no whitening of edges was observed, and the boundary line was thin and therefore not noticeable. 3: Whitening of edges was observed upon close inspection, and the boundary line was a little thick but not noticeable. 2: Whitening of edges was observed, and the boundary line was thick and noticeable, but at a practically acceptable level. 1: Whitening of edges was observed, and the boundary line was very thick and noticeable, and was not practically acceptable.

[0140] (19) Conspicuousness of the Boundary (Due to Color Difference Between Light Reflecting Material and Transparent Hard Material) The conspicuousness of the boundary due to the color difference between the light reflecting material and the transparent hard material of the projection image display member was evaluated visually. The evaluation criteria are as follows. <Evaluation Criteria> A: There was almost no color difference, and the boundary was not noticeable. B: There was a slight color difference, but the boundary was not noticeable. C: There was a color difference, but the boundary was noticeable at a level acceptable for practical use. D: The color difference was large, and the boundary was noticeable to an extent that was not acceptable for practical use.

[0141] (20) Visibility of scenery through the light-reflecting material The visibility of scenery through the light-reflecting material of the projection image display member was evaluated visually. The evaluation criteria are as follows: <Evaluation criteria> 5: No glare, and the outside scenery can be clearly seen. 4: Almost no glare, and the outside scenery can be seen without any problems. 3: A little glare is seen, and the outside scenery can be seen to some extent. 2: Glare is seen, and the outside scenery is difficult to see, but within an acceptable range. 1: Glare is seen or transparency is low, and the outside scenery cannot be seen.

[0142] (21) Reworkability After a light-reflective material was attached to a transparent hard material via an adhesive layer, the peelability from the transparent hard material and the re-adhesion of the peeled adhesive layer were evaluated. The evaluation criteria were as follows. <Evaluation criteria> A: Peeling was easy from the edge, and after re-adhesion, the light-reflective material had sufficient adhesion to not peel off even when rubbed with a finger. B: Peeling was easy from the edge, and after re-adhesion, the light-reflective material had sufficient adhesion to not peel off easily even when rubbed with a finger. C: Peeling was easy from the edge, but after re-adhesion, the light-reflective material easily peeled off when rubbed with a finger. D: Peeling was difficult, and adhesive residue remained.

[0143] [Thermoplastic resins, etc. used to obtain laminated films] The thermoplastic resins shown in Table 1 were used to obtain the laminated films of each Example and Comparative Example. In Table 1, "mol %" indicates the proportion of the dicarboxylic acid unit and the diol unit, respectively, when the total amount thereof is taken as 100 mol %.

[0144]

[0145] [Laminated Film A] Polyethylene terephthalate (Resin 1) was used as thermoplastic resin A. Furthermore, a polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 80 mol% of a terephthalic acid component relative to the total acid components and 20 mol% of a 2,6-naphthalenedicarboxylic acid component relative to the total acid components) (Resin 2) was used as thermoplastic resin B. The prepared thermoplastic resins A and B were each fed into two single-screw extruders and melted at a temperature of 280°C. Next, thermoplastic resin A and thermoplastic resin B were each passed through five FSS-type leaf disc filters, and then, while being metered with a gear pump, were joined in a lamination device with 801 slits so that the mass ratio of thermoplastic resin A to thermoplastic resin B (A / B) was 1. A molten resin laminate was obtained in which 801 layers were alternately laminated in the thickness direction, with thermoplastic resin A positioned as the outermost layer on both sides. The molten resin laminate was then extruded from a die and cooled and solidified on a casting drum at a temperature of 25°C and a speed of 4 m / min to obtain a cast film. The resulting cast film was heated with a group of rolls set at 60°C, then stretched 3.3 times in the longitudinal direction with rolls set at 87°C at a stretching rate of 50% / sec, and then cooled. The uniaxially stretched film thus obtained was introduced into a tenter, preheated with hot air at 90°C, and then stretched 3.4 times in the width direction at a stretching rate of 5% / sec at 95°C. The stretched film was then heat-treated with hot air at 210°C in the tenter, followed by a 3% relaxation treatment (Rx) in the width direction under the same temperature conditions, and then cooled to room temperature. Thus, a laminated film A having a thickness of 80 μm was obtained.

[0146] [Laminated Films B to K] Laminated films B to K were produced in the same manner as laminated film A, except that the number of layers, the resin of each layer, and the film-forming conditions were as shown in Table 1.

[0147] The evaluation results of each of the obtained laminated films are shown in Table 2. Note that laminated film J was obtained as a single-layer film of resin 1.

[0148]

[0149] [Coating materials, etc. used in manufacturing projection image display members] The coating material for forming the protective layer was a mixture of the hard coat (HC) raw materials shown in Table 3-1 at the mixing ratios shown in Table 3-2 (the mixing ratios shown in Table 3-2 are the ratios of the entire composition including the solvent). The components shown in Table 3-3 were used to form the low refractive index layer, those shown in Table 3-4 were used for the adhesive layer, and those shown in Table 3-5 were used for the colored layer.

[0150]

[0151]

[0152]

[0153]

[0154]

[0155] Example 1 A laminate film A was cut out to the size of the projection image display member used in the evaluation of each item, and a protective layer was laminated thereon by the following procedure. 67 parts by mass of Momentive Material Performance Hardcoat UVHC7400 and 33 parts by mass of Nippon Shokubai nanoparticles (silica particles (average particle diameter: 20 nm)) IX-3-TR-M-02-J were mixed to obtain a protective layer-forming coating material (HC-1) (the mixing ratio here refers to the ratio of the entire composition including the solvent). HC-1 was applied to one side of the laminate film A using a stainless steel coating wire bar #12 manufactured by RD Specialties, and the film was left to stand in a high-temperature bath at 100°C to volatilize the solvent. Subsequently, a UV irradiation device (Eye Graphics ECS-401GX) was used to apply an integrated light dose of 770 mJ / cm ２ HC-1 was cured by irradiating with UV light so that the temperature reached 100°C, forming a protective layer with a total thickness of 10 μm. Then, using a roller, an adhesive layer AS-PSA003 manufactured by Arakawa Chemical Industries, Ltd. was laminated on the surface of the laminate film opposite the protective layer surface to form an adhesive layer. Subsequently, a projection image display member was produced as described in "(14) Production of projection image display member." Subsequently, a transparent display system was produced by the method described in "(16) Display properties." The evaluation results of the projection image display member and the transparent display system are shown in Table 4-1.

[0156] (Examples 2 to 32, 34 to 42, Comparative Examples 1 and 2) Projection image display members and transparent display systems were fabricated in the same manner as in Example 1, except that the materials, configurations, cutting conditions, and transparent display configurations used were as shown in Tables 3-1 to 3-4 and Tables 4-1 to 4-4. The evaluation results are shown in Tables 4-1 to 4-4. The green glass used as the transparent hard material in Example 12 was green glass manufactured by Kodama Glass Co., Ltd. (average reflectance at wavelengths of 400 nm to 700 nm measured at an incident angle of 0°: 76%).

[0157] (Example 33) A 0.103 μm thick SiO ２ The sputtering equipment used was a single-wafer sputtering equipment UB-1 manufactured by ULVAC, and the conditions were as follows: discharge gas: Ar, pressure: 1.2 Pa, substrate temperature: room temperature, RF output: 500 W, and film formation time: 40 seconds. Thereafter, a projection image display member and a transparent display system were fabricated in the same manner as in Example 1. The evaluation results are shown in Table 4-4.

[0158]

[0159]

[0160]

[0161]

[0162] In Tables 4-3 and 4-4, "1000x" in the abrasion resistance test means that scratches were generated after 1000 cycles.

[0163] In Example 33, since there was no protective layer, the "pressure at which cracks occur in the protective layer" was deemed unmeasurable. In addition, in Example 10, the reflection wavelength band could not be identified using method (1), and the display quality evaluated using method (13) was "D," so both the "reflection wavelength band when P waves are incident at an incident angle of 60°" and the "double image visibility" were deemed undeterminable.

[0164] From Tables 4-1 to 4-4, in Examples 1 to 42 in which the angle α was in the range of 60° or more and 120° or less, the whitening of the edge of the light-reflective material was suppressed, the boundary line between the light-reflective material part and the part without the light-reflective material was less noticeable, and the appearance was good. In contrast, in Comparative Examples 1 and 2, the boundary line was very thick and noticeable due to the whitening of the edge of the light-reflective material, which was not acceptable for practical use.

[0165] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-097214) filed on June 17, 2024, the entirety of which is incorporated by reference.

[0166] The present invention can provide a projection image display member that suppresses deterioration of visibility due to a boundary between a light-reflecting material portion and a light-non-reflecting material portion, and has a good appearance. Because of these excellent characteristics, the projection image display member of the present invention can be suitably used in amusement applications such as head-up displays for manned transportation, transparent screens used for spatial presentation, and electronic signage applications such as signage and show windows.

[0167] 1: Projected image display member 2: Light-reflecting material (laminated film) 3: Transparent hard material 4: Adhesive layer 5: Cross-sectional image of light-reflecting material after binarization 6: Approximate line a 7: Approximate line b 8: Perpendicular line between approximate lines a and b 9: Approximate line c 10: Approximate line d 11: Approximate line e (straight line (line Y) adjacent to a line originating from the surface opposite to the surface facing the transparent hard material) 12: Point 1 13: Point 2 14: Point 3 15: Point 4 16: Approximate line f (straight line (line X) originating from the surface opposite to the surface facing the transparent hard material) 17: Transparent display system 18: Image projector 19: Image light 20: Observer 21: Landscape 22: Incident angle (θ) of image light 23: Normal to projected image display member 24: Angle relative to the normal to the cut surface of the light-reflecting material when viewed from the observer 25: Angle α

Claims

1. A projection image display component having a structure in which a light-reflecting material is laminated on at least a portion of a transparent hard material, and in a thickness direction cross section at the midpoint of each side of the light-reflecting material, the angle α between a straight line originating from the surface opposite the surface facing the transparent hard material and a straight line adjacent to the straight line is 60° or more and 120° or less.

2. A projection image display member according to claim 1, wherein the average reflectance at wavelengths of 400 to 700 nm when P waves are incident on the surface of said light-reflecting material at an incident angle of 60° is 10% or more and 60% or less.

3. A projection image display member according to claim 1 or 2, wherein the average transmittance of light having a wavelength of 400 to 700 nm when the light is incident on the surface of the light reflecting material at an incident angle of 0° is 50% or more and 100% or less.

4. A projection image display member according to any one of claims 1 to 3, wherein the color difference between an area where the light-reflecting material is not present and an area where the light-reflecting material and the transparent hard material are laminated is 0 or more and 20 or less.

5. A projection image display member according to any one of claims 1 to 4, which has a colored layer on at least a portion of the light-reflecting material, and when light is incident, the average transmittance of the light having a wavelength of 400 to 700 nm is 0% or more and 30% or less.

6. From the center of the colored layer of the light-reflecting material toward the boundary with the transparent hard material, L ＊ 6. The projection image display member according to claim 5, wherein at least a portion of the value has a positive gradient.

7. A projection image display member according to any one of claims 1 to 6, wherein the light-reflecting material is a laminated film having a structure in which two or more different types of thermoplastic resin layers are regularly laminated in 51 to 10,001 layers.

8. A projection image display member according to any one of claims 1 to 7, which comprises a protective layer on the outermost surface on the side of the light-reflecting material.

9. The projection image display member according to claim 8, wherein the concentration of inorganic particles contained in the protective layer is 10% by mass or more and 60% by mass or less.

10. The projection image display member according to claim 8 or 9, wherein the inorganic particle occupancy rate on the outermost surface of said protective layer is 0.1% or more and 60% or less.

11. The projection image display member according to any one of claims 8 to 10, wherein the pressure at which cracks occur in the protective layer is 1 GPa or more and 200 GPa or less, as measured by a micro-scratch test method in accordance with JIS R-3255:1997.

12. The projection image display member according to any one of claims 8 to 11, wherein the protective layer has an arithmetic mean roughness of 0.10 nm or more and 0.90 nm or less.

13. A projection image display member according to any one of claims 1 to 7, comprising at least one low refractive index layer having a refractive index of 1.00 or more and 1.50 or less on the outermost surface on the side of the light-reflecting material.

14. The projection image display member according to any one of claims 1 to 13, which has an adhesive layer between the transparent hard material and the light-reflecting material.

15. The projection image display member according to claim 14, wherein the adhesive strength of the adhesive layer to the glass surface measured at a peel angle of 180° is 0.01 N / 25 mm or more and 10.00 N / 25 mm or less.

16. A transparent display system comprising a projection image display member according to any one of claims 1 to 15, and an image projector that irradiates the light-reflecting material in the projection image display member with light containing 51% to 100% P-waves.

17. The transparent display system of claim 16, wherein the angle between the incident surface direction of the light irradiated from the projection image display member and the direction in which the reflectivity of the P wave of the light-reflecting material is maximum is between 0° and 20°.

18. The transparent display system according to claim 16 or 17, wherein when the incident angle of light from the image projector is angle θ, the angle α and the angle θ satisfy |180 - (θ + α)| ≧ 20.

19. A head-up display using the transparent display system according to any one of claims 16 to 18.

20. A manned transportation vehicle equipped with the transparent display system according to any one of claims 16 to 18.

21. A screen using the transparent display system according to any one of claims 16 to 18.

Images