JP7087806B2 - Video display system - Google Patents

Description

The present invention relates to a video display system including a reflective screen.

Conventionally, various reflective screens have been developed that reflect and display the image light projected from the image source (see, for example, Patent Document 1). In particular, a translucent reflective screen having transparency is in increasing demand because it can see the scenery on the other side of the reflective screen and has excellent design (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-40892

It has been proposed that a semi-transmissive reflective screen as described above is provided on the front window of the vehicle, and various information is displayed to the driver by projecting image light from the projector. However, in the conventional reflective screen, a part of the image light projected from the projector may block the driver's field of view, and it is required to ensure a good field of view.

An object of the present invention is to provide an image display system capable of ensuring a good field of view.

The present invention solves the above-mentioned problems by the following solution means. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited thereto.
The first invention has a reflective screen (20) that has transparency and displays a part of the projected image light by diffuse reflection, and an image source that projects the image light from the observer side toward the reflected screen. An image display system comprising (LS) and capable of visually recognizing the image light diffusely reflected by the reflection screen at a specific observation position, wherein the reflection screen has light transmission and a unit optical shape portion. A Frenel lens-shaped optical shape layer in which a plurality of the light elements are arranged, and a reflection layer (24) provided at least at a position where the image light is incident on the optical shape layer and diffusely reflect a part of the incident image light. In the left-right direction (X direction) of the reflection screen, the optical center (C) of the Fresnel lens shape is deviated from the geometric center (A) of the reflection screen, and the image source is the reflection screen. The image light is arranged so as to project the image light onto the region (100) of the optical shape layer excluding the optical center of the Frenel lens shape, and the observation position is a half-value angle of the brightness of the image light diffusely reflected by the reflection screen. The present invention relates to a video display system (1) provided within the range of.
The second invention is the image display system (1) of the first invention, in which the position of the observation position in the left-right direction of the reflection screen is the position of the optical center of the Fresnel lens shape of the reflection screen. It is a video display system that matches.
A third aspect of the invention is the image display system (1) of the first or second aspect, wherein the optical center of the Fresnel lens shape of the reflective screen is within the display area of the reflective screen, and at least one. This is an image display system having a light transmitting portion (200) in which the reflective layer is not formed.
A fourth invention is the image display system (1) of any one of the first to third inventions, wherein the reflective layer is an image display system that transmits a part of incident light.
A fifth aspect of the invention is the video display system (1) of any one of the first to fourth inventions, wherein a plurality of the video sources are provided, and each of the video sources (LS1, LS2) is the reflection. This is a video display system that projects video light onto different areas of the screen.

According to the present invention, it is possible to provide a video display system that can secure a good field of view.

It is a front view which shows the area around the driver's seat of the automobile VC provided with the image display system 1 of 1st Embodiment. It is a top view which shows the area around the driver's seat of the automobile VC provided with the image display system 1 of 1st Embodiment. It is sectional drawing which shows the arrangement of the reflection screen 20 and the projector LS which make up the image display system 1. It is a partial cross-sectional view of the front window 2. It is a top view when the reflection screen 20 is seen from the −z side to the + z side. It is a figure explaining the relationship between a reflection screen 20 and an observation position. It is a figure explaining the half-value angle in a luminance distribution. It is a figure explaining the manufacturing method of the reflection screen 20. It is a figure explaining the manufacturing method of the front window 2. It is a figure explaining the image display system 1A of the 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. It should be noted that each of the figures shown below, including FIG. 1, is a diagram schematically shown, and the size and shape of each part are appropriately exaggerated in order to facilitate understanding.
In the present specification, terms that specify a shape or a geometric condition, for example, terms such as parallel and orthogonal, have the same optical function in addition to the exact meaning and can be regarded as parallel or orthogonal. It shall also include states with a degree of error.
In the present specification, numerical values such as dimensions of each member and material names described are examples of embodiments, and the present invention is not limited to these, and may be appropriately selected and used.

(First Embodiment)
FIG. 1 is a front view showing the vicinity of the driver's seat of an automobile VC provided with the video display system 1 of the first embodiment. FIG. 1 shows a state when the direction of the front window 2 (the traveling direction of the automobile VC) is viewed from the driver's seat side of the automobile VC.
FIG. 2 is a plan view showing the vicinity of the driver's seat of the automobile VC provided with the video display system 1 of the first embodiment. FIG. 2 shows a state when the driver's seat of the automobile VC is viewed downward from the roof (not shown) side.
FIG. 3 is a cross-sectional view showing the arrangement of the reflective screen 20 and the projector LS constituting the image display system 1.

Each figure including FIG. 1 shows a XYZ (xyz) Cartesian coordinate system. In this coordinate system, the left-right direction (width direction) of the automobile VC is the X direction, the vertical direction (vertical direction) is the Y direction, and the traveling direction of the automobile VC is the Z direction. In the X direction, the right direction is the + X direction and the left direction is the −X direction. In the Y direction, the upward direction is the + Y direction and the downward direction is the −Y direction. In the Z direction, the rear direction of the vehicle VC is the −Z direction, and the front direction of the vehicle VC is the + Z direction. The "direction" is also appropriately referred to as a "side".

Further, the screen left-right direction (horizontal direction) of the front window 2 is the x direction, the screen vertical direction is the y direction, and the thickness direction is the z direction. In the x direction, the right direction of the screen is the + x direction, and the left direction of the screen is the −x direction. In the y direction, the upper direction of the screen is the + y direction, and the lower direction of the screen is the −y direction. In the z direction, the inside of the vehicle VC is in the −z direction, and the outside (rear surface) side of the vehicle VC is in the + z direction. The "screen" of the front window 2 refers to a display area of the reflective screen 20 (described later) provided inside. In the present embodiment, since the sizes of the front window 2 and the reflective screen 20 are substantially the same, the display area of the reflective screen 20 is appropriately referred to as “the screen of the front window 2”.

As shown in FIGS. 1 and 2, the automobile VC includes a front window 2 and an interior panel 3 on the front side (+ Z side) when viewed from the vehicle interior.
As shown in FIG. 3, the front window 2 is inclined at a predetermined angle with respect to the traveling direction (Z direction) of the automobile VC in the thickness direction (z direction). Along with this, the screen vertical direction (y direction) of the front window 2 is also tilted at a predetermined angle with respect to the vertical direction (Y direction) of the automobile VC.
In the present embodiment, the screen of the front window 2 will be described as a planar shape, but the present invention is not limited to this, and for example, it is a three-dimensional curved shape in which the entire screen is convex toward the outside (+ Z) side of the vehicle. There may be.

The interior panel 3 is a decorative panel provided on the lower side (−Y side) of the front window 2. As shown in FIG. 1, on the right side of the interior panel 3, a steering wheel 4 serving as a control stick of an automobile VC and an instrument 5 such as a speedometer are arranged. Further, inside the interior panel 3, projectors LS1 and LS2, which will be described later, are arranged. Note that, in FIG. 1 and the like, the projectors LS1 and LS2 are exposed from the interior panel 3, but in reality, only the projection port is exposed from the interior panel 3.

As shown in FIG. 2, the automobile VC is provided with a driver's seat S on the right side (+ X side) and the rear side (−Z side) of the front window 2. By sitting in the driver's seat S, the driver D can visually recognize the light such as the scenery incident from the outside of the vehicle and the image light diffusely reflected by the reflection screen 20 (described later). Hereinafter, the position of the driver's seat S is also referred to as an "observation position of image light" or an "observation position". The observation position of the image light is not limited to the driver's seat S, and may be, for example, a passenger seat (not shown) provided on the left side (-X side) of the front window 2.

As shown in FIG. 3, the automobile VC includes a video display system 1. The video display system 1 is a device that displays various information on the front window 2. The image display system 1 includes a reflective screen 20 and projectors (image sources) LS1 and LS2.
The reflection screen 20 is an optical member that displays a part of the image light projected from the projectors LS1 and LS2 toward the driver located on the −Z side by diffuse reflection. The reflective screen 20 is provided inside the front window 2.
The reflection screen 20 displays an image by diffusely reflecting the image light projected from the projectors LS1 and LS2. Therefore, for example, even if the image light is projected from an image source for a head-up display device (for example, a liquid crystal display device, an organic EL device, etc.), the image cannot be displayed on the reflective screen 20.

The front window 2 is configured as a laminated glass in which an intermediate layer (30, 50) for preventing scattering and a reflective screen 20 are sandwiched between a pair of glass plates (10, 40) described later.
The reflective screen 20 has transparency so that the driver D can observe the scenery outside (+ Z side) of the front window 2 in the use state where the image light is not projected. That is, the reflective screen 20 is configured as a transflective reflective screen.

As described above, in the present embodiment, the display area of the reflective screen 20 is substantially the same as the size of the front window 2. The display area of the reflective screen 20 is an area in which the images projected from the projectors LS1 and LS2 can be displayed, and the images are not displayed on the entire surface of the front window 2. The image is actually displayed in the projection range of the projectors LS1 and LS2. The projection ranges of the projectors LS1 and LS2 are different from each other.

In FIG. 1, the display area of the reflective screen 20 provided inside the front window 2 is shown by diagonal lines (imaginary lines). Further, the shaded display area indicates the area of the light reflecting portion 100 (described later) in which the reflecting layer (described later) is formed. The circular region without the diagonal line indicates the light transmitting portion 200 (described later) in which the reflective layer is not formed. The light transmitting portion 200 of the present embodiment includes an optical center having a Fresnel lens shape, which will be described later. The detailed configuration of the front window 2 will be described later.

The projectors LS1 and LS2 (hereinafter, also collectively referred to as “projector LS”) are image sources that project the image light L onto the front window 2 (reflection screen 20). The projector LS is configured as a short focus type projector. Of the projectors LS, the projector LS1 is arranged in the screen right direction (+ x direction) of the front window 2 and in the screen lower direction (−y direction) of the front window 2. Further, the projector LS2 is arranged in the left direction (-x direction) of the screen of the front window 2 and in the lower direction (-y direction) of the screen of the front window 2.

As shown in FIGS. 1 and 2, the projectors LS1 and LS2 are arranged so as to project image light onto different regions of the reflective screen 20. That is, the projector LS1 mainly projects the image light to the area of the front window 2 in the right direction (+ x direction) of the screen and in the lower direction (−y direction) of the screen. Further, the projector LS2 mainly projects the image light to the area of the front window 2 in the left direction (-x direction) of the screen and the lower direction (-y direction) of the screen. The region where the projectors LS1 and LS2 project the image light onto the reflection screen 20 is the region of the light reflection unit 100 excluding the light transmission unit 200.
The position where the projector LS is arranged is not limited to the position shown in FIG. 1 and the like, and may be appropriately changed based on the interior design, display content, and display position of the automobile VC. Further, the number of projectors is not limited to two, and may be one or three or more.

The projector LS can project the image light L diagonally upward from a position where the distance from the driver side (-Z side) of the reflective screen 20 is significantly shorter than that of the conventional general-purpose projector. Therefore, the projector LS has a shorter projection distance to the front window 2 (reflection screen 20) than the conventional general-purpose projector. Further, in the projector LS, the angle at which the projected image light L is incident on the reflection screen 20 is large, and the amount of change in the incident angle (the amount of change from the minimum value to the maximum value) is also large.

Next, the configuration of the front window 2 will be described.
FIG. 4 is a partial cross-sectional view of the front window 2, and is an enlarged view of a range corresponding to the α portion of FIG. FIG. 4 is a cross section when the front window 2 is viewed from the + x side to the −x side, as in FIG. 3, and shows a cross section of a region to be the light reflecting portion 100. Further, in FIG. 4, the front window 2 is drawn parallel to the vertical direction (Y direction).
FIG. 5 is a plan view of the reflection screen 20 when viewed from the −z side to the + z side.

As shown in FIG. 4, the front window 2 includes a first glass plate 10, a reflective screen 20, a first intermediate layer 30, a second glass plate 40, and a second intermediate layer 50.
The first glass plate 10 is a transparent member arranged on the most indoor side (−z side) in the front window 2. As the first glass plate 10, for example, materials such as soda lime glass (blue plate glass), borosilicate glass (white plate glass), quartz glass, soda glass, and potash glass can be used. Further, the thickness of the first glass plate 10 is preferably in the range of, for example, 2 to 3 mm.

The reflective screen 20 is a layer provided on the back surface side (+ z side) of the first glass plate 10 with the first intermediate layer 30 interposed therebetween. As shown in FIG. 4, the reflective screen 20 includes a base material layer 21, a first optical shape layer 22, a second optical shape layer 23, and a reflective layer 24. Of these, the first optical shape layer 22, the second optical shape layer 23, and the reflective layer 24 constitute an optical shape layer.
As shown in FIG. 3, the reflection screen 20 diffusely reflects a part of the light incident through the first glass plate 10 to the driver side (−Z side) and transmits the others to the back surface side (+ Z side). It has a light reflecting unit 100 and a light transmitting unit 200 that transmits incident light to the back surface side (+ Z side).

As shown in FIG. 5, the region serving as the light transmitting portion 200 is a circular region including the optical center C having a Fresnel lens shape in a plan view of the reflective screen 20 when viewed from the thickness direction (z direction). The reflective layer 24 (described later) is not formed in the optical shape layer in the region corresponding to the light transmitting portion 200.
The light transmitting unit 200 is on the driver side (+ x side) of the front window 2 when the screen of the front window 2 is viewed from the −z side, and is slightly above the screen (+ y side) from the middle of the front window 2. It is formed in. This position is a position that can be visually recognized without diverting the line of sight when the driver turns his / her line of sight forward (direction of travel of the vehicle VC). Since the image light is not projected on the light transmitting portion 200, the driver can secure a good field of view.

For example, the size of the light transmitting portion 200 is set in the range of about 40 to 70 mm in diameter for in-vehicle use. The shape of the light transmitting portion 200 is not limited to a circle, and may be, for example, a rectangle, an ellipse, a square, a trapezoid, or any other shape.
The light reflecting portion 100 is a region of the reflecting screen 20 excluding the light transmitting portion 200. A reflective layer 24 is formed on the optical shape layer in the region corresponding to the light reflecting portion 100.

The base material layer 21 is a flat plate-shaped member that serves as a base for forming the reflective screen 20, and is provided on the innermost side (-z side) of the reflective screen 20. The base material layer 21 is formed of, for example, a polyester resin such as PET having high light transmittance, an acrylic resin, a styrene resin, an acrylic styrene resin, a polycarbonate resin, an alicyclic polyolefin resin, or the like.

The first optical shape layer 22 is a layer provided on the back surface side (+ z side) of the base material layer 21. As the first optical shape layer 22, an ultraviolet curable resin such as a urethane acrylate-based, polyester acrylate-based, epoxy acrylate-based, polyether acrylate-based, polythiol-based, or butadiene acrylate-based resin having high light transmittance can be used. The resin constituting the first optical shape layer 22 is not limited to the ultraviolet curable resin, and may be, for example, an electron beam curable resin.

A plurality of unit optical shape portions 22a are provided on the inner surface (-z side) of the first optical shape layer 22.
As shown in FIG. 5, the unit optical shape portion 22a has a plurality of circular Fresnel lens shapes arranged concentrically (hereinafter, also simply referred to as “Fresnel lens shape”).
Here, with respect to the optical center C of the Fresnel lens shape, as shown in FIG. 3, the angle (α) of the first inclined surface 22b (see FIG. 4) of the unit optical shape portion 22a is the vertical direction (α) of the front window 2. The part that becomes zero with respect to the y direction).

As shown in FIG. 5, in the present embodiment, when the outer shape of the reflective screen 20 is a horizontally long rectangular shape, the optical center C of the Fresnel lens shape is on the right side with respect to the geometric center A of the reflective screen 20. It is provided at a position shifted to the + x side). Further, the optical center C of the Fresnel lens shape coincides with the geometric center C1 of the light transmitting portion 200 in a plan view of the reflective screen 20 from the thickness direction (z direction). The geometric center C1 of the light transmitting portion 200 and the optical center C having a Fresnel lens shape do not have to coincide with each other. Further, the optical center C of the Fresnel lens shape may be provided at a position shifted to the left side (-x side) with respect to the geometric center A of the reflection screen 20. In that case, the observation position of the image light described later may be provided on the left side (-X side) of the reflection screen 20.

On the other hand, as shown in FIG. 2, the observation position (driver's seat S) of the image light by the driver D is located at a position corresponding to the optical center C of the Fresnel lens shape in the left-right direction (X direction) of the reflection screen 20. It will be provided. As will be described later, if the condition of being within the range of the half-value angle of the brightness of the image light diffusely reflected by the reflection screen 20 is satisfied, the observation position is Frenell in the left-right direction (X direction) of the reflection screen 20. It does not have to completely match the optical center C of the lens shape.

Returning to FIG. 4, the configuration of the reflective screen 20 will be described.
The unit optical shape portion 22a has a triangular cross-sectional shape. The unit optical shape portion 22a includes a first inclined surface 22b to which the image light is directly incident, and a second inclined surface 22c to which the image light is not directly incident. In one unit optical shape portion 22a, the first inclined surface 22b is provided at a position adjacent to the second inclined surface 22c with the apex t interposed therebetween.

In the unit optical shape portion 22a, the angle formed by the first inclined surface 22b with the surface parallel to the xy plane is α. The angle formed by the second inclined surface 22c with the surface parallel to the xy surface is β (β> α). The arrangement pitch of the unit optical shape portion 22a is P. The height of the unit optical shape portion 22a (the dimension from the apex t in the thickness direction to the point v which is the valley bottom between the unit optical shape portions 22a) is h. These angles and dimensions are set according to the tilt angle when the front window 2 is attached to the vehicle VC, the projection angle of the image light from the projector LS, and the like.

Although not shown, the surfaces of the first inclined surface 22b and the second inclined surface 22c of the unit optical shape portion 22a are rough surfaces having fine and irregular uneven shapes. In this fine uneven shape, the convex shape and the concave shape are irregularly formed in the two-dimensional direction. The size, shape, height, etc. of the convex and concave shapes are irregular.

The second optical shape layer 23 is a layer provided on the back surface side (+ z side) of the first optical shape layer 22. The second optical shape layer 23 is provided to flatten the back surface of the reflective screen 20. As the second optical shape layer 23, the same ultraviolet curable resin as the first optical shape layer 22 described above can be used. It is desirable that the refractive index of the second optical shape layer 23 is the same as that of the first optical shape layer 22.

The reflection layer 24 is a layer formed on the first inclined surface 22b of the unit optical shape portion 22a at a position corresponding to the light reflection portion 100 among the plurality of unit optical shape portions 22a. The reflective layer 24 is a semi-transmissive diffuse reflection layer that diffusely reflects a part of the incident light and transmits the others. The ratio of the reflectance and the transmittance of the reflective layer 24 can be appropriately set, but the image light is diffusely reflected satisfactorily and the light incident from the front side (+ Z side) of the automobile VC is sufficiently transmitted for driving. From the viewpoint of ensuring good visibility of the person, it is desirable that the transmittance is 70% or more.

As described above, the first inclined surface 22b and the second inclined surface 22c are formed with fine and irregular uneven shapes. The reflective layer 24 is formed with the uneven shape of the first inclined surface 22b and the second inclined surface 22c maintained. Therefore, the surface of the reflective layer 24 on the first optical shape layer 22 side (image source side) and the surface on the second optical shape layer 23 side (back surface side) are the same as the first inclined surface 22b and the second inclined surface 22c. It is a rough surface with fine and irregular uneven shape.
The reflective layer 24 has a function of diffusing and reflecting a part of the incident light due to a fine and irregular uneven shape, and transmitting at least a part of the incident light without diffusing.

The reflective layer 24 is made of a metal having high light reflectivity, for example, aluminum, silver, nickel, or the like. In this embodiment, the reflective layer 24 is formed by depositing aluminum. Further, the reflective layer 24 may be formed by sputtering a metal having high light reflectivity, transferring a metal foil, applying a paint containing a metal thin film, or the like.

The first intermediate layer 30 is a layer provided between the first glass plate 10 and the reflective screen 20 (base material layer 21). The first glass plate 10 and the reflective screen 20 are joined by the first intermediate layer 30. The first intermediate layer 30 is provided to prevent fragments of the first glass plate 10 from scattering when the front window 2 is damaged. As the first intermediate layer 30, for example, PVB (polyvinyl butyral) can be used. The thickness of the first intermediate layer 30 is preferably in the range of 0.3 to 0.8 mm. Further, it is desirable that the refractive index of the first intermediate layer 30 is the same as that of the first glass plate 10 and the first optical shape layer 22 (reflection screen 20).
The second glass plate 40 is a transparent member provided on the backmost side (+ z side) of the front window 2. As the second glass plate 40, the same material as that of the first glass plate 10 can be used. The thickness of the second glass plate 40 is preferably in the range of 2 to 3 mm.

The second intermediate layer 50 is a layer provided between the second glass plate 40 and the reflective screen 20 (second optical shape layer 23). The second glass plate 40 and the reflective screen 20 are joined by the second intermediate layer 50. The second intermediate layer 50 is provided to prevent the fragments of the second glass plate 40 from scattering when the front window 2 is damaged. As the second intermediate layer 50, PVB can be used as in the first intermediate layer 30. The thickness of the second intermediate layer 50 is preferably in the range of 0.3 to 0.8 mm. Further, it is desirable that the refractive index of the second intermediate layer 50 is the same as that of the first glass plate 10 and the first optical shape layer 22 (reflection screen 20).

Next, in the video display system 1, the relationship between the reflection screen 20 and the observation position will be described.
FIG. 6 is a diagram illustrating the relationship between the reflection screen 20 and the observation position. In FIG. 6, the position of the driver D is the observation position of the image light.
FIG. 7 is a diagram illustrating a half-value angle in the luminance distribution. In FIG. 7, the horizontal axis represents the observation angle in the left-right direction (X direction), and the vertical axis represents the brightness.

As shown in FIG. 6, when the image lights L1 and L2 are projected from the projectors LS1 and LS2 toward the reflection screen 20, a part of each image light is transferred to the light reflection unit 100 (see FIG. 1) of the reflection screen 20. , Diffuse reflection on the driver side (-Z side). In order to visually recognize each image light diffusely reflected by the reflection screen 20 at the optimum brightness, the half-value angle αH of the brightness of each image light is set at the observation position of the image light in the left-right direction (X direction) of the reflection screen 20. It may be provided within the range of the overlapping width W.

As shown in FIG. 7, the half-value angle αH means an observation angle at which the brightness of light becomes half the maximum value in the left-right direction from the center of the screen surface of the reflection screen 20 where the brightness of light becomes the maximum value. .. In the reflective screen 20 of the present embodiment, the half-value angle αH required for visually recognizing the image light with the optimum brightness is, for example, 10 to 20 °. By providing the observation position of the image light in the range of the width W shown in FIG. 6, the driver D has the optimum brightness (at least half the maximum value) of the image light projected from either the left or right side. It can be seen. When there is one projector LS, the observation position may be provided within the range of the half-value angle αH of the brightness of one video light.

Next, the optical paths of the image light L incident on the front window 2 of the present embodiment and the light G incident from the outside of the vehicle will be described.
As shown in FIG. 1, the projectors LS1 and LS2 of the present embodiment have different positions of the front window 2 in the left-right direction of the screen, but both of them have video light on the light reflecting unit 100 in the lower direction (-y direction) of the screen. Is arranged to project. Here, an optical path when the image light is configured to be projected onto the light reflecting unit 100 in the upward direction (+ y direction) of the screen will also be described.

As shown in FIG. 3, the image light L projected from the projector LS is incident on the driver side (inside the vehicle, −z side) of the front window 2. The image light L incident on the front window 2 passes through the base material layer 21 of the reflective screen 20 and is incident on the driver-side surface of the first optical shape layer 22.
In FIG. 3, the driver's eye E is shown in the vicinity of the front window 2 for ease of understanding, but the driver's eye E is actually located further away from the front window 2. , The light L2, L6, etc., which will be described later, are all delivered to the driver's eye E.

Of the image light L, a part of the light L1 projected mainly on the light reflecting portion 100 on the upper side (+ y side) of the screen is the first inclined surface of the unit optical shape portion 22a formed on the first optical shape layer 22. After incident on 22b, it is diffusely reflected by the reflective layer 24 (see FIG. 4), reaches the driver side (−z side) as light L2, and reaches the driver's eye E. Further, some of the other light of the image light L1 passes through the reflection layer 24 formed as the semi-transmissive diffuse reflection layer, and then the second optical shape layer 23, the second intermediate layer 50, and the second glass. It passes through the plate 40 and is emitted as light L3 from the back surface (+ Z side) surface of the front window 2 to the outside of the vehicle.
Further, the other light (other than L2 and L3) of the image light L1 is interfacially reflected on the surface of the first glass plate 10 of the front window 2, and the light L4 is obliquely upward (+ y side) of the front window 2. Since it is reflected, most of it does not reach the driver's eye E.

Further, of the image light L, a part of the light L5 projected mainly to the light reflecting portion 100 on the lower side (−y side) of the screen is the unit optical shape portion 22a formed on the first optical shape layer 22. After incident on the first inclined surface 22b, it is diffusely reflected by the reflective layer 24, reaches the driver side (−z side) as light L6, and reaches the driver's eye E. Further, some of the other light of the image light L5 passes through the reflection layer 24 formed as the semi-transmissive diffuse reflection layer, and then the second optical shape layer 23, the second intermediate layer 50, and the second glass. It passes through the plate 40 and is emitted as light L7 from the back surface (+ Z side) surface of the front window 2 to the outside of the vehicle. The image light L5 is interfacially reflected on the surface of the first glass plate 10 of the front window 2, but the first glass plate 10 on which the light L5 is incident and the reflection layer 24 (reflection screen 20) are not parallel to each other. The light L9 surface-reflected on the surface of the first glass plate 10 does not reach the driver's eye E.

On the other hand, the light L10 such as the scenery incident from the outside of the automobile is incident from the surface on the back side (outside of the vehicle, + z side) of the front window 2, and a part of the light is transmitted through the reflective layer 24 and the driver. It reaches the side (-z side). Further, although not shown, some other light passes through the second inclined surface 22c (see FIG. 4) and reaches the driver side. Further, other light is reflected by the reflective layer 24 and emitted to the outside of the vehicle (+ z side).

As described above, according to the image display system 1 of the first embodiment, the image light projected from the projector LS is reflected to the driver side by the reflection screen 20 (reflection layer 24) and is visible through the front window 2. Light such as scenery can be transmitted to the driver side. According to this, the driver of the automobile VC can visually recognize various information without looking away from the front (the traveling direction of the automobile VC), so that the automobile VC can be driven safely.
Further, since the image light is not projected on the light transmitting portion 200, the driver can visually recognize the outside world through the light transmitting portion 200 of the front window 2 (reflection screen 20) when the line of sight is directed forward. Therefore, in the video display system 1 of the first embodiment, the driver can secure a good field of view.

In the image display system 1 of the first embodiment, the observation position (driver's seat S) of the image light by the driver is a position that coincides with the optical center C of the Fresnel lens shape in the left-right direction (X direction) of the reflection screen 20. It is provided in. According to this, in the reflection screen 20, the image light reflected by the optical shape layer in the shape of the Frenel lens of the light reflection unit 100 travels in the direction of the driver, so that a bright image can be visually recognized on the entire reflection screen 20. Further, since the image light is not projected on the light transmitting portion 200, the light that is interfacially reflected on the surface of the first glass plate 10 and looks like a spot to the driver is not generated, which is more preferable.

Next, a method of manufacturing the reflective screen 20 will be described.
FIG. 8 is a diagram illustrating a method of manufacturing the reflective screen 20. 8 (A) to 8 (C) are views showing a process until the reflective screen 20 is manufactured.
As shown in FIG. 8A, the nozzle 110 is used to draw the long base material 21'from the tubular winding body R to form the first optical shape layer 22 (see FIG. 4). Is filled on the long base material 21'. Subsequently, the long base material 21'is pressed by the molding roll 120 having the uneven shape corresponding to the unit optical shape portion 22a (see FIG. 4), and the first optical shape layer is placed on the long base material 21'. 22 forms a continuous first optical shape band 22'. Then, after the first optical shape band 22'is cured, the long base material 21'is wound around the winding body R. The first optical shape layer 22 of the present embodiment is a so-called roll-to-roll in which the first optical shape layer 22 is continuously formed on a long base material 21'wound in a roll shape and then wound up in a roll shape again. It can be manufactured efficiently by the method.

Next, as shown in FIG. 8B, the long base material 21'wound on the winding body R is placed in the vacuum vapor deposition apparatus 130, and the vapor deposition source 140 is placed at a predetermined position. .. The thin-film deposition source 140 is composed of a vapor-deposited metal 140a (for example, aluminum) and a heating body 140b for heating the vapor-deposited metal 140a.
Then, while pulling out the long base material 21'on which the first optical shape band 22'is formed from the winding body R, the vapor-deposited metal 140a is heated and melted by the heating body 140b in the vapor deposition source 140 to evaporate. The evaporated metal vaporized metal 140a adheres to the first inclined surface 22b (see FIG. 4) of the unit optical shape portion 22a formed in the first optical shape band 22'to form the reflective layer 24. The reflective layer 24 is formed in a region corresponding to the light reflecting portion 100 (see FIG. 1).

On the other hand, in the reflection screen 20, when the region corresponding to the light transmitting portion 200 (see FIG. 1) reaches the position of the vapor deposition source 140, the stencil mask M is arranged. By arranging the stencil mask M, the vapor-deposited metal 140a is not deposited on the first optical shape band 22', so that the light transmitting portion 200 in which the reflective layer 24 is not formed can be formed. When the vapor-deposited metal 140a is deposited in the region corresponding to the light reflecting portion 100 (see FIG. 1), the stencil mask M is retracted to a position away from the long base material 21'. By undergoing such a thin-film deposition step, a region (light reflecting portion 100) in which the first optical shape band 22'and the reflective layer 24 are sequentially formed on the long base material 21', and the first optical shape band 22' A laminated body F1 having a region (light transmitting portion 200) in which only is formed is obtained. Next, the laminated body F1 is wound around the winding body R and taken out from the vacuum vapor deposition apparatus 130.

Next, as shown in FIG. 8C, while pulling out the laminated body F1 from the winding body R, a second surface is formed on the surface of the laminated body F1 on the side where the unit optical shape portion 22a (see FIG. 4) is formed. The resin for forming the optical shape layer 23 (see FIG. 4) is filled from the nozzle 150. Subsequently, the laminated body F1 is pressed by the forming roll 160 forming a flat surface to form a second optical shape band 23'in which the second optical shape layer 23 is continuous on the laminated body F1. As a result, a region (light reflecting portion 100) in which the first optical shape band 22', the reflective layer 24, and the second optical shape band 23' are laminated in this order on the long base material 21', and the first optical shape band. A laminated body F2 having a region (light transmitting portion 200) in which 22'and a second optical shape band 23' are laminated in this order can be obtained. In the region of the light transmitting portion 200, since the first optical shape band 22'and the second optical shape band 23'are in close contact with each other, the incident light is not reflected at the interface.
Then, after the second optical shape band 23'is sufficiently cured, the laminated body F2 is moved to the cutting portion 170. The reflective screen 20 is completed by cutting the laminated body F2 to a predetermined size in the cutting portion 170.

Next, a method of manufacturing the front window 2 will be described.
FIG. 9 is a diagram illustrating a method of manufacturing the front window 2. 9 (A) and 9 (B) are diagrams showing a process until the front window 2 is manufactured. Note that FIG. 9 shows a cross section of a region (light reflecting portion 100) in which the reflecting layer 24 is formed.
First, as shown in FIG. 9A, the first intermediate layer 30 is formed on the surface of the reflective screen 20 on the base material layer 21 side, and the first glass plate 10 is laminated on the first intermediate layer 30. Next, as shown in FIG. 9B, a second intermediate layer 50 is formed on the surface of the reflective screen 20 on the side of the second optical shape layer 23, and the second glass plate 40 is laminated on the second intermediate layer 50. Then, the laminated body F3 is obtained by sandwiching it in a pressing roll (not shown) and temporarily crimping it.

Subsequently, the laminated body F3 is arranged in an autoclave pressure cooker (not shown), and the reflective screen 20, the first glass plate 10, and the second glass plate 40 are placed in an environment of predetermined temperature and pressure, respectively. 1 The intermediate layer 30 and the second intermediate layer 50 are brought into close contact with each other. As a result, the reflective screen 20 and the first glass plate 10 and the second glass plate 40 are joined by the first intermediate layer 30 and the second intermediate layer 50, respectively, to complete the front window 2.

(Second Embodiment)
FIG. 10 is a diagram illustrating the video display system 1A of the second embodiment.
The image display system 1A of the second embodiment is different from the first embodiment in that the reflective screen 20 is provided inside the vehicle (−z side) of the front window 2A. In the video display system 1A of the second embodiment, other configurations are the same as those of the first embodiment. Therefore, in FIG. 10, only the front window 2A and the reflective screen 20 are shown, and the projector LS is not shown. Further, in the description and drawings of the second embodiment, the same members as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and duplicate description will be omitted.

In the image display system 1A of the second embodiment, the reflective screen 20 is attached to the surface of the front window 2A on the inside (−z side) of the vehicle.
The front window 2A includes a first glass plate 10, a second glass plate 40, and an intermediate layer 60. The front window 2A of the present embodiment is configured as a general laminated glass in which the first glass plate 10 and the second glass plate 40 are joined by an intermediate layer 60.

The configuration of the reflective screen 20 is the same as that of the first embodiment. The display area of the reflective screen 20 is substantially the same as the size of the front window 2A. That is, the reflective screen 20 covers almost the entire surface of the front window 2A. The reflective screen 20 of the second embodiment is attached to the first glass plate 10 of the front window 2A via the bonding layer 70 on the surface of the second optical shape layer 23 on the front window 2A side (+ z side). .. As the bonding layer 70, a light-transmitting adhesive material or an adhesive material can be used. Specifically, as the bonding layer 70, for example, acrylic resin, urethane resin, epoxy resin, phenol resin, silicone resin and the like can be used.

Even in the reflective screen 20 of the second embodiment and the front window 2A provided with the reflective screen 20, since the image light is not projected on the light transmitting portion 200, the driver attaches the image light to the front window 2A when the line of sight is directed forward. The outside world can be visually recognized through the light transmitting portion 200 of the attached reflective screen 20. Therefore, in the video display system 1A of the second embodiment, the driver can secure a good field of view.
Further, in the second embodiment, since the front window 2A to which the reflective screen 20 is attached may be a laminated glass having a general configuration, the image display system 1A can be mounted on more vehicle models.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made as in the modified forms described later, and these are also the present invention. Included within the technical scope of. Moreover, the effects described in the embodiments are merely a list of the most suitable effects resulting from the present invention, and are not limited to those described in the embodiments. The above-described embodiment and the modified form described later may be used in combination as appropriate, but detailed description thereof will be omitted.

(Transformed form)
(1) In the above embodiment, an example in which a plurality of unit optical shape portions 22a of the reflection screen 20 are concentrically arranged in a circular Fresnel lens shape (see FIG. 5) has been described, but the present invention is not limited thereto. A linear Fresnel lens shape in which a plurality of unit optical shape portions 22a of the reflection screen 20 are arranged in parallel may be used. Even in that case, the reflection is performed by providing the observation position (driver's seat S) of the image light by the driver at a position corresponding to the optical center C of the linear Fresnel lens shape in the left-right direction (X direction) of the reflection screen 20. A bright image can be visually recognized on the entire screen 20.

(2) In the above embodiment, the configuration in which the reflective layer 24 is not formed in the light transmitting portion 200 has been described, but the present invention is not limited to this, and the reflective layer 24 may be formed in the light transmitting portion 200. In that case, the transmittance of the reflective layer 24 formed on the light transmitting portion 200 may be increased, and the transmittance of the reflective layer 24 formed on the light reflecting portion 100 may be increased.

(3) In the above embodiment, an example in which the video display system 1 (1A) is applied to the front window 2 (2A) of an automobile has been described, but the present invention is not limited thereto. The image display system 1 (1A) may be applied to a side window, a rear window, or the like of an automobile, or may be applied to a window of a vehicle other than the automobile. Further, the video display system 1 (1A) may be applied to a video display system that displays video in an indoor partition, for example, or an advertisement or the like in a show window of a store or the like that transmits light from the outside world such as a background. It may be applied to a video display system that displays the video of.

(4) In the above embodiment, an example in which the reflective layer 24 is formed on the entire surface of the first inclined surface 22b (see FIG. 4) in the light reflecting unit 100 has been described, but the present invention is not limited thereto. In the light reflecting portion 100, the reflecting layer 24 may be formed as a part of the first inclined surface 22b (see FIG. 4). According to this configuration, the image light projected from the projector LS is diffusely reflected by the reflection layer 24 of the light reflection unit 100, and the light incident from the outside of the vehicle is reflected from the portion where the reflection layer 24 of the first inclined surface 22b is not formed. Can be transmitted from to the inside of the car. Therefore, the light such as the scenery seen through the front window 2 (2A) can be transmitted in a clearer state.
(5) In the second embodiment, the reflective screen 20 may be attached to the vehicle outer side (+ z side) surface of the front window 2. Further, in the second embodiment, the reflective screen 20 may be provided on, for example, a side window, a rear window, or the like.

1,1A Video display system 2,2A Front window 20 Reflective screen 21 Optical shape layer 24 Reflective layer 100 Light transmitter 200 Light reflector LS (LS1, LS2) Projector

Claims (5)

A reflective screen that has transparency and displays a part of the projected image light by diffuse reflection,
It is equipped with an image source that projects image light from the observer side toward the reflective screen.
An image display system that allows the image light diffusely and reflected by the reflection screen to be visually recognized at a specific observation position.
The reflective screen has a light-transmitting property, is provided with a Frenel lens-shaped optical shape layer in which a plurality of unit optical shape portions are arranged, and at least a position where image light is incident on the optical shape layer, and the incident image light. With a reflective layer that diffuses and reflects part of the
In the left-right direction of the reflective screen, the optical center of the Fresnel lens shape is deviated from the geometric center of the reflective screen.
The image source is arranged so as to project the image light onto the region of the optical shape layer excluding the optical center of the Fresnel lens shape of the reflection screen.
The observation position is provided within the range of the half-value angle of the brightness of the image light diffusely reflected by the reflection screen .
The observation position is an image display system in which the position of the reflection screen in the left-right direction coincides with the position of the optical center of the Fresnel lens shape of the reflection screen . The video display system according to claim 1 .
An image display system having a light transmitting portion in which the optical center of the Fresnel lens shape of the reflective screen is within the display area of the reflective screen and the reflective layer is not formed at least in a part thereof. A reflective screen that has transparency and displays a part of the projected image light by diffuse reflection,
It is equipped with an image source that projects image light from the observer side toward the reflective screen.
An image display system that allows the image light diffusely and reflected by the reflection screen to be visually recognized at a specific observation position.
The reflective screen has a light-transmitting property, is provided with a Frenel lens-shaped optical shape layer in which a plurality of unit optical shape portions are arranged, and at least a position where image light is incident on the optical shape layer, and the incident image light. With a reflective layer that diffuses and reflects part of the
In the left-right direction of the reflective screen, the optical center of the Fresnel lens shape is deviated from the geometric center of the reflective screen.
The image source is arranged so as to project the image light onto the region of the optical shape layer excluding the optical center of the Fresnel lens shape of the reflection screen.
The observation position is provided within the range of the half-value angle of the brightness of the image light diffusely reflected by the reflection screen.
An image display system having a light transmitting portion in which the optical center of the Fresnel lens shape of the reflective screen is within the display area of the reflective screen and the reflective layer is not formed at least in a part thereof. The video display system according to any one of claims 1 to 3.
The reflective layer is an image display system that transmits a part of incident light. The video display system according to any one of claims 1 to 4.
A plurality of the video sources are provided.
Each of the video sources is a video display system that projects video light onto different regions of the reflective screen.

Images