JP2020170113A - Information display system and vehicular information display system utilizing the same - Google Patents

Abstract

To provide an information display system capable of displaying video information of high resolution, and a vehicular information display system capable of displaying information to the inside and outside of a vehicle utilizing the information display system.SOLUTION: An information display system which displays a video to the inside or outside of a space in one direction through a transparent projection target member installed in the space comprises: a video projection device which is arranged in the space, and modulates luminous flux from a light source to generate and project video light; a transparent sheet which is provided on an inner side face of a display region set at a part of the projection target member; and a light direction conversion panel which changes the direction of the video light from the video projection device toward the transparent sheet in the display region. The transparent sheet includes: an optical retardation plate, an absorption type polarizing plate which absorbs a specific polarized wave; and a transparent diffusion sheet having light diffusing action, the information display system projects the video light having its direction changed by the light direction conversion panel toward the inside or outside of the space.SELECTED DRAWING: Figure 2

Description

The present invention is an information display capable of displaying an image in one direction to the inside or the outside of a store (space) by reflecting or transmitting through a transparent member that partitions a space such as a show window glass. Regarding the system, the information display system projects image light onto the windshield, rear glass, side glass, combiner, etc. of automobiles, trains, aircraft, etc. (hereinafter collectively referred to as "vehicles"). The present invention relates to a vehicle information display system capable of displaying in one direction with respect to the inside or the outside of the vehicle.

As an information display system of this kind, it is already known that an image is generally displayed using a transparent or reflective screen. For example, according to the following Patent Documents 1 and 2, binders and fine particles are used. Transparent or reflective screens with a light diffusing layer containing the above are already known.

On the other hand, for information video equipment for vehicles and information display systems that use it, video light is projected onto the windshield and combiner of automobiles to form a virtual image, and traffic information such as route information and traffic congestion information and the remaining amount of fuel are used. A so-called head-up display (HUD: Head-Up-Display) device that displays automobile information such as the temperature of cooling water and the temperature of cooling water is already known by, for example, Patent Document 3 below. In this type of information display device, in general, in order to enable monitoring of video information as a virtual image for the purpose of reducing the movement of the driver's viewpoint, the video displayed on the video display device is concave. Many of them use an optical system including a mirror (action of a convex lens) to project to the driver's viewpoint.

Japanese Patent No. 6133522 Japanese Patent No. 6199530 JP-A-2015-194707

However, in the above-mentioned information display system or device which is the conventional technology, consideration is not given to efficiently delivering the image light to the observer to improve the light utilization efficiency, and as a result, the system or device It was difficult to reduce the power consumption of the image projection device including the light source.

Further, in an information display device for a vehicle represented by a head-up display or the like, AR (Augmented-Reality) information which is a virtual image is displayed so as not to obstruct the view outside the vehicle from the driver. For example, when displaying information such as a map, high resolution and high visibility are also required. Therefore, a liquid crystal display element (liquid crystal display panel) is often used because a high-quality image can be easily obtained and is inexpensive. On the other hand, in order to reduce the size of the set, a small size is used. Since a liquid crystal display element is used, the resolution of the obtained projected image is insufficient, and a new problem that it is not suitable for displaying a high-resolution image displayed on a smartphone or the like has been clarified.

Further, in the information display device for vehicles of the conventional head-up display system, when the inclination angle of the windshield is large (close to vertical), the place where the image device is placed is limited to the space between the steering wheel and the windshield. The second problem is that there are restrictions on the structural requirements of the vehicle that can be installed, that is, the image light from the image device is reflected by the windshield in a direction that does not reach the driver's eyes and the system cannot be established. It became clear.

Further, the conventional head-up display type information display device for a vehicle is not intended to display video information to the outside of the vehicle. Therefore, when the video information is to be displayed to the outside of the vehicle, a video display device such as a display is mounted inside the vehicle, and the video information is displayed through the glass of the vehicle. However, in that case, these video display devices obstruct the driver's field of vision, which is not preferable for safe driving.

In Patent Document 1 and Patent Document 2, which are prior arts, a reflective screen or a transparent screen provided with a light diffusion layer containing binders and fine particles used in an information display device is disclosed, but video light is observed. No consideration is given to improving the efficiency of light utilization by efficiently delivering to people, and no teaching is given on the application in vehicles and the specific method, form, or configuration for that purpose.

The present invention can display high-resolution video information even on the glass surface of a show window instead of the conventional information display system or device, and efficiently delivers video light to an observer to improve light utilization efficiency. By doing so, an information display system capable of significantly reducing the power consumption of a system or device including a light source or an image projection device is provided. Furthermore, using the information display system, the inside of the vehicle can be visually recognized by passengers including the driver through the shield glass including the windshield, rear glass, and side glass of the vehicle, regardless of the inclination angle. It is possible, but on the other hand, it is invisible from the outside of the vehicle, or it is visible from the outside of the vehicle, but on the other hand, it is invisible to the passengers inside the vehicle. An object of the present invention is to provide a so-called vehicle information display system capable of unidirectional display.

In the present invention, in order to achieve the above-mentioned object, first, an information display system for displaying an image in one direction with respect to the inside or the outside of the space through a transparent projected member installed in the space. An image projection device that is arranged inside the space and modulates a light beam from a light source to generate and project image light, and a transparent device provided on the inner surface of a display area set as a part of the projected member. The transparent sheet includes a sheet and an optical direction conversion panel that converts the direction of the image light from the image projection device toward the transparent sheet in the display area, and the transparent sheet absorbs a retardation plate and a specific polarization. Information display that includes an absorption-type polarizing plate and a transparent diffusion sheet material having a light diffusing effect, and projects the video light whose direction has been changed by the light direction conversion panel toward the inside or the outside of the space. The system is provided.

Further, in the present invention, in order to achieve the above-mentioned object, a vehicle information display system that displays information inside or outside the vehicle by using a part of a transparent projected member constituting the vehicle as a display area. An image projection device that projects the image light of the information provided inside the vehicle, and a transparent sheet provided on the inner surface of the display area set as a part of the projected member. A light direction conversion panel for converting the direction of the image light from the image projection device toward the transparent sheet is provided, and the transparent sheet includes a retardation plate, an absorption type polarizing plate that absorbs a specific polarized light, and the like. Provided is an information display system for a vehicle, which includes a transparent diffusion sheet material having a light diffusing effect and projects the video light whose direction is changed by the light direction conversion panel toward the inside or the outside of the vehicle. To.

According to the present invention, high-resolution video information can be displayed even on the glass surface of a show window, and the power consumption is significantly reduced by efficiently delivering the video light to the observer and improving the light utilization efficiency. It is possible to provide a new and highly usable information display system that can be reduced. Furthermore, using the information display system, it is visible to passengers including the driver inside the vehicle through the shield glass including the windshield, rear glass, and side glass of the vehicle, but on the other hand, A so-called unidirectional display that is invisible from the outside of the vehicle, or is visible from the outside of the vehicle, but is invisible to the passengers (passengers) inside the vehicle. It is possible to provide an information display system for vehicles.

It is a figure which shows an example of the whole structure of the information display system which concerns on one Example of this invention. It is a figure which shows an example of a more specific configuration of an information display system. It is a figure which shows an example of the specific structure of the light source device which comprises the image projection device (Example 1) of an information display system. It is a figure which shows an example of the specific structure of the light source device which comprises the image projection device (Example 1) of an information display system. It is a figure which shows an example of the specific structure of the light source device which comprises the image projection device (Example 2) of an information display system. It is sectional drawing for demonstrating the structure of the light source which performs polarization conversion in an image projection apparatus (Example 2), and its operation. It is sectional drawing for demonstrating the structure of the light source which performs polarization conversion in an image projection apparatus (Example 2), and its operation. It is a figure which shows an example of the structure of the lenticular lens which constitutes the image projection apparatus of an information display system. It is a figure which includes the graph which shows the image light diffusion characteristic of an image display device. It is a figure which includes the graph which shows the image light diffusion characteristic of an image display device. It is sectional drawing which shows an example of the structure of the unidirectional transparent sheet (reflection type) which constitutes the image projection apparatus of an information display system. It is sectional drawing which shows an example of the structure of the unidirectional transparent sheet (transmissive type) which constitutes the image projection apparatus of an information display system. It is sectional drawing for demonstrating the principle of the light direction conversion panel which comprises the image projection apparatus of an information display system. It is sectional drawing which shows an example of the schematic structure of the protective cover which constitutes the image projection apparatus of an information display system. It is a figure which shows the example which applied the information display system to a bus which is a vehicle. It is a figure which shows the example which applied the information display system to a train which is a vehicle. It is a figure which includes the graph which shows the reflectance of the glass with respect to p-polarized light and s-polarized light of natural light such as sunlight. It is a figure which includes the graph which shows the wavelength distribution of natural light such as sunlight. It is a figure which shows an example of the specific configuration of the display system for a vehicle which applied the information display system to a vehicle. It is a figure which shows an example of the more specific configuration of the display system for a vehicle which applied the information display system to a vehicle. It is a figure which shows the example which applied the information display system for a vehicle to a passenger car. This is an example of a schematic configuration diagram showing a head-up display (HUD) type information display device including its peripheral device configuration. It is a figure which shows an example of the arrangement in the cockpit of the automobile which mounted the HUD device together with the information display device. It is a figure which shows an example of the arrangement in the cockpit of an automobile which displays the information display device in one direction with high resolution with respect to the inside of a vehicle. It is a figure which shows the example which displays the information to the outside of a vehicle through the rear glass of a vehicle. It is a figure which shows an example of the configuration at the time of displaying the image | image from the HUD apparatus using an information display system.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings and the like. The present invention is not limited to the following description, and various modifications and modifications by those skilled in the art can be made within the scope of the technical idea disclosed in the present specification. In addition, in all the drawings for explaining the present invention, the same reference numerals may be given to those having the same function, and the repeated description thereof may be omitted.

<Information display system>
FIG. 1 shows the overall configuration of an information display system according to an embodiment of the present invention. For example, in a store or the like, a space is partitioned by a show window (also referred to as "wind glass") 220 which is a translucent member such as glass, and according to the information display system of this embodiment, such transparent It is possible to display the image in one direction with respect to the inside or the outside of the store (space) by reflecting or transmitting through the member. In FIG. 1, the inside of the show window 220 (inside the store) is shown in the depth direction so that the outside (for example, the sidewalk) is in front.

More specifically, as shown in FIG. 1, above the show window 220, which is a transparent member such as glass, a light source is provided to generate and project an image light to be displayed, which will be described in detail below. The image projection device 48 is arranged, and the image light generated by the image projection device 48 is a transparent sheet (film) 51 attached to the light direction conversion panel 54 and the show window 220, which are also described in detail below. By the action of, it is selectively displayed in one direction with respect to the inside or the outside. According to this, it is possible to display various information inside or outside the show window 220 by using the show window 220, and it is possible to remarkably improve the utilization efficiency of the show window.

Next, FIG. 2 shows a more specific configuration of the above-mentioned information display system. The image display element 52 constituting the image projection device 48 is, for example, relatively large in size exceeding 6 inches. It is composed of various liquid crystal display panels. Further, in order to perform correction at a level that does not cause a practical problem by distortion correction, the resolution of the panel is preferably 1280 × 720 dots or more.

Further, the image projection device 48 includes the above-mentioned liquid crystal display panel 52 and a light source device 101 constituting the light source. In FIG. 2, the light source device 101 is deployed above the above-mentioned liquid crystal display panel 52 together with the above-mentioned liquid crystal display panel 52. It is shown as a perspective view.

As shown by an arrow 30 in FIG. 2, the liquid crystal display panel (element) 52 obtains a highly directional illumination luminous flux by a light source device 101, which is a backlight device, and modulates it according to an input video signal. The image light is emitted toward the transparent sheet 51 provided on the surface of the wind glass 220. Further, in FIG. 2, the information display system includes a liquid crystal display panel 52 constituting the image projection device 48, an optical direction conversion panel 54 for controlling the directivity characteristic of the luminous flux emitted from the light source device 101, and if necessary. A narrow angle diffuser plate (not shown) is provided accordingly. That is, polarizing plates are provided on both sides of the liquid crystal display panel 52, and video light having a specific polarization is emitted by modulating the light intensity with the video signal (see arrow 30 in FIG. 2). .. As a result, a desired image is projected onto the window glass 220 via the optical direction conversion panel 54, and the inside or outside observer of the store (space) via the transparent sheet 51 provided on the surface thereof. Reflects or transmits toward the eye 8 (FIG. 2 shows an example of reflection). Reference numeral 50 in the drawing indicates a protective cover provided on the surface of the above-mentioned optical direction conversion panel 54.

In this embodiment, in order to improve the utilization efficiency of the luminous flux 30 emitted from the light source device 101 and significantly reduce the power consumption, the image projection device 48 including the light source device 101 and the liquid crystal display panel 52 is described below. As described above, the utilization efficiency of the light from the light source device 101 (see the arrow 30 in FIG. 2) is improved, and further, the transparency provided on the surface of the wind glass 220 by an optical component such as a lenticular lens described below. Directivity is given to the brightness of the image light transmitted or diffused through the sheet 51. According to this, the image light from the image projection device 48 efficiently reaches the observer inside the show window 220 (inside the store) or the observer outside (for example, the sidewalk). As a result, it is possible to significantly reduce the power consumption of the image projection device 48 including the light source device 101.

<Example 1 of image projection device>
FIG. 3 shows a specific configuration of the light source device 101 described above. However, in FIG. 3, the light source device 101 of FIG. 2 is shown upside down. The light source device 101 is formed of, for example, plastic or the like in the case shown in FIG. 2 or the like, and is configured by accommodating an LED element, a collimator, a synthetic diffusion block, a light guide, and the like, which will be described in detail later. A liquid crystal display panel 52 constituting the image projection device 48 is attached to the upper surface thereof. Further, an LED (Light Emitting Diode) elements 14a and 14b, which are semiconductor light sources, and an LED substrate 102 on which the control circuit thereof is mounted are attached to one side surface of the case of the light source device 101, and the outside of the LED substrate 102. A heat sink 103, which is a member for cooling the heat generated by the LED element and the control circuit, is attached to the side surface (see FIG. 2).

On the other hand, the liquid crystal display panel frame attached to the upper surface of the case of the light source device 101 includes a liquid crystal display panel 52 attached to the frame, and FPC (Flexible Printed Circuits) electrically connected to the liquid crystal display panel. : Flexible wiring board) 403 (see FIG. 2) and the like are attached and configured. That is, the liquid crystal display panel 52, which is a liquid crystal display element, will be described in detail later, but together with the LED elements 14a and 14b, which are solid light sources, will be used as a control signal from a control circuit (not shown here) constituting the electronic device. A display image is generated by modulating the intensity of transmitted light based on the above.

Subsequently, the configuration of the optical system housed in the case of the light source device 101 will be described in detail below with reference to FIGS. 4 (a) and 4 (b) together with FIG.

3 and 4 show a plurality of (two in this example) LED elements 14a and 14b constituting the light source, which are attached to the LED collimator 15 at predetermined positions. Each of the LED collimators 15 is made of a translucent resin such as acrylic. Then, as shown in FIG. 4B, the LED collimator 15 has a conical convex outer peripheral surface 156 obtained by rotating a parabolic cross section, and at the top thereof, a convex portion (that is, a convex portion) is formed at the center thereof. , Convex lens surface) It has a recess 153 forming 157. Further, the central portion of the flat surface portion has a convex lens surface (or a concave lens surface recessed inward) 154 that protrudes outward. The parabolic surface 156 forming the conical outer peripheral surface of the LED collimator 15 is set within an angle range within which the light emitted from the LED elements 14a and 14b in the peripheral direction can be totally reflected. Alternatively, a reflective surface is formed.

On the other hand, the LED elements 14a and 14b are respectively arranged at predetermined positions on the surface of the so-called LED substrate 102, which is the circuit board thereof. The LED substrate 102 is arranged and fixed to the LED collimator 15 so that the LED element 14a or the LED element 14b on the surface thereof is located at the center of the recess 153, respectively.

According to this configuration, among the light emitted from the LED element 14a or the LED element 14b by the LED collimator 15 described above, the light emitted upward (to the right in the figure) from the central portion thereof is particularly emitted. The two convex lens surfaces 157 and 154 that form the outer shape of the LED collimator 15 are focused to produce parallel light. Further, the light emitted from the other portion toward the peripheral direction is reflected by the paraboloid forming the conical outer peripheral surface of the LED collimator 15, and is similarly condensed into parallel light. In other words, according to the LED collimator 15 in which a convex lens is formed in the central portion thereof and a radial surface is formed in the peripheral portion thereof, almost all the light generated by the LED element 14a or the LED element 14b is regarded as parallel light. It becomes possible to take out, and it becomes possible to improve the utilization efficiency of the generated light.

A polarization conversion element 21 described in detail below is provided on the light emitting side of the LED collimator 15. As is clear from FIG. 4 and the like, the polarization conversion element 21 has a columnar translucent member having a parallelogram cross section (hereinafter, parallelogram column) and a columnar member having a triangular cross section (hereinafter, triangle). In combination with the translucent member of the pillar), a plurality of members are arranged in an array in parallel with the plane orthogonal to the optical axis of the parallel light from the LED collimator 15. Further, a polarizing beam splitter (hereinafter abbreviated as "PBS") film 211 and a reflective film 212 are alternately provided at the interface between the adjacent translucent members arranged in an array. Further, a 1λ / 2 phase plate 213 is provided on the exit surface from which the light incident on the polarization conversion element 21 and transmitted through the PBS film 211 is emitted.

Further, a rectangular synthetic diffusion block 16 shown in FIG. 4A is provided on the exit surface of the polarization conversion element 21. That is, the light emitted from the LED element 14a or the LED element 14b becomes parallel light by the action of the LED collimator 15, enters the synthetic diffusion block 16, is diffused by the texture 161 on the exit side, and then leads as described below. It reaches the light body 17.

The light guide body 17 is a rod-shaped member having a substantially triangular cross section (see FIG. 4B) made of a translucent resin such as acrylic, and is clear from FIGS. 3 and 4. As described above, the light guide body light incident portion (light guide body light incident surface) 171 facing the exit surface of the synthetic diffusion block 16 via the first diffuser plate 18a, and the light guide body light reflecting portion (light reflecting body) forming a slope. The light guide body light reflecting surface) 172 and the light guide body light emitting portion (light guide body light emitting surface) 173 facing the liquid crystal display panel 52 of the liquid crystal display element via the second diffuser plate 18b are provided. ..

As shown in FIG. 3, which is a partially enlarged view of the light guide body light reflecting portion 172 of the light guide body 17, a large number of reflecting surfaces 172a and connecting surfaces 172b are alternately formed in a sawtooth shape. .. Then, the reflecting surface 172a (a line segment rising to the right in the figure) forms αn (n: a natural number, for example, 1 to 130 in this example) with respect to the horizontal plane indicated by the alternate long and short dash line in the figure. There is. As an example, here, αn is set to 43 degrees or less (however, 0 degrees or more).

The light guide body incident portion 171 is formed in a curved convex shape inclined toward the light source side. According to this, the parallel light from the exit surface of the synthetic diffusion block 16 is diffused through the first diffusion plate 18a and incident on the light guide body 17, and as is clear from FIG. 3, the light guide body The incident portion 171 slightly bends (deflects) upward to reach the light guide body light reflecting portion 172, where the light is reflected and reaches the liquid crystal display panel 52 provided on the upper emitting surface in the drawing.

As described in detail above, the image projection device 48 described above further improves the light utilization efficiency and its uniform illumination characteristics, and at the same time, includes a modularized S-polarized wave light source device, which is compact and low cost. It will be possible to manufacture with. In the above description, the polarization conversion element 21 is attached after the LED collimator 15, but the present invention is not limited to this, and the same operation can be performed by providing the polarization conversion element 21 in the optical path leading to the liquid crystal display panel. It will be obvious to those skilled in the art that the effect will be obtained.

A large number of reflecting surfaces 172a and connecting surfaces 172b are alternately formed in a sawtooth shape on the light guide body light reflecting portion 172, and the illumination light beam is totally reflected on each reflecting surface 172a and is upwardly reflected. Further, the light emitting portion 173 of the light guide body is provided with a narrow angle diffuser plate to be incident on the optical direction conversion panel 54 that controls the directivity characteristics as a substantially parallel diffused light beam, and is incident on the liquid crystal display panel 52 from an oblique direction. .. In this embodiment, the light direction conversion panel 54 is provided between the light guide body emission surface 173 and the liquid crystal display panel 52, but it goes without saying that the same effect can be obtained even if the light direction conversion panel 54 is provided on the emission surface of the liquid crystal display panel 52. Let's go.

<Example 2 of image projection device>
Further, a second embodiment of the above-mentioned image projection device 48 is shown in FIG. The light source device 101 is configured by attaching a light source unit in which a plurality of LEDs 201, which are light sources, are arranged to a light receiving unit 202 provided on the end surface of the light guide body 203, and the divergent luminous flux from the LEDs is regarded as substantially parallel light according to the lens shape of the light receiving unit. , As shown by an arrow, the inside of the light guide body 203 is guided (direction parallel to the drawing), and the light beam direction changing means 204 is directed toward the liquid crystal display panel 52 arranged substantially parallel to the light source body. (Direction perpendicular to the front from the drawing) Exit. By optimizing the distribution (density) of the light flux direction changing means inside the light guide body, the uniformity of the light flux incident on the liquid crystal display panel 52 is controlled.

FIG. 6 is a cross-sectional layout diagram for explaining the configuration of the light source of this embodiment and its action in the light source device 101 including the light guide body 203 and the LED 201 described above. The light source device 101 is composed of, for example, a light guide body 203 provided with a light beam direction changing means 204 on the surface or inside formed of plastic or the like, an LED element 201 as a light source, a reflection sheet 205, a retardation plate 202, and the like. A liquid crystal display panel 52 having a polarizing plate on a light source light incident surface and an image light emitting surface is attached to the upper surface of the image projection device 48.

Further, a film or sheet-shaped reflective polarizing plate 49 is provided on the light source light incident surface of the liquid crystal display panel 52 corresponding to the light source device 101, and the polarization of one side of the natural light beam 210 emitted from the LED light source (for example). The P wave) 212 is selectively reflected, reflected by the reflecting sheet 205 provided on one surface (lower part of the drawing) of the light guide body 203, and directed toward the liquid crystal display panel 52 again. Therefore, a retardation plate (λ / 4 plate) is provided between the reflective sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the light is reflected by the reflective sheet 205 and passed twice. Converts the reflected light beam from P-polarized light to S-polarized light to improve the efficiency of using the light source light as the image light. The image luminous flux whose light intensity is modulated by the image signal on the liquid crystal display panel 52 (arrow 213 in FIG. 6) is incident on the wind glass 220 at a large incident angle as shown in FIG. 1, so that the transparent sheet 51 The reflectance is increased, and good diffusion characteristics can be obtained for monitoring inside or outside the store (space).

FIG. 7 is a cross-sectional layout diagram for explaining the configuration and operation of the light source of the present embodiment for polarization conversion in the light source device 101 including the light guide body 203 and the LED 201, similarly to FIG. The light source device 101 is composed of, for example, a light guide body 203 provided with a light beam direction changing means 204 on the surface or inside formed of plastic or the like, an LED element 201 as a light source, a reflection sheet 205, a retardation plate 202, and the like. A liquid crystal display panel 52 having a polarizing plate on a light source light incident surface and an image light emitting surface is attached to the upper surface of the image projection device 48.

Further, a film or sheet-shaped reflective polarizing plate 49 is provided on the light incident surface of the liquid crystal display panel 52 corresponding to the light source device 101, and one side of the natural light beam 210 emitted from the LED light source is polarized (for example, S wave). The 211 is selectively reflected, reflected by the reflective sheet 205 provided on one surface of the light guide 203, and directed to the liquid crystal display panel 52 again. A retardation plate (λ / 4 plate) is provided between the reflective sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the light is reflected by the reflective sheet 205 and reflected by passing it twice. The light beam is converted from S-polarized light to P-polarized light to improve the utilization efficiency of the light source light as image light. As shown in FIG. 1, the image luminous flux whose light intensity is modulated by the image signal on the liquid crystal display panel 52 is transparent because the reflection on the surface is reduced even if it is incident on the wind glass 220 at a large incident angle. The sheet 51 can efficiently diffuse the image light to the outside of the room.

<Lenticular lens>
Further, in order to control the diffusion distribution of the image light from the liquid crystal display panel 52, a lenticular as shown in FIG. 8 is placed between the light source device 101 and the liquid crystal display panel 52 or on the surface of the liquid crystal display panel 52. By providing the lens 800 and optimizing the lens shape, it is possible to control the emission characteristics in one direction (the image light in the X-axis direction in FIG. 8). Further, the image luminous flux from the image projection device 48 is emitted toward the window glass 220.

Here, the operation of the lenticular lens 800 will be described. By optimizing the lens shape, the lenticular lens 800 can be emitted from the image projection device 48 described above and efficiently reflected or diffused on the transparent sheet 51 on the wind glass 220. That is, as shown in FIGS. 9A and 9B, for example, two lenticular lenses are combined with respect to the image light from the image projection device 48, and in the X-axis and Y-axis directions, which are the surfaces thereof. The brightness (relative brightness) of the image light can be controlled according to the reflection angle (0 degrees in the vertical direction). In this embodiment, with such a lenticular lens 800, the image light is efficiently produced by increasing the brightness (relative brightness) of the light due to reflection or diffusion by making the brightness characteristic in the vertical direction steeper as compared with the conventional case. It is designed to reach the observer's eye 8 (see FIG. 2).

FIG. 10 shows an example of the characteristics of the lenticular lens used in this embodiment. In this example, in particular, the characteristic in the X direction (vertical direction) is shown. In the characteristic O, the peak in the light emission direction is at an angle of about 30 degrees upward from the vertical direction (0 degrees) and is symmetrical vertically. It shows the brightness characteristics. Further, the characteristics A and B in the figure further show an example of a characteristic in which the image light above the peak brightness is condensed at around 30 degrees to increase the brightness (relative brightness). Therefore, in these characteristics A and B, the brightness (relative brightness) of light is sharply reduced as compared with the characteristic O at an angle exceeding 30 degrees.

That is, according to the above-mentioned lenticular lens, the image light from the image projection device 48 can be reflected or diffused by increasing (enhancing) its brightness in a specific direction via the transparent sheet 51 described below. it can. This makes it possible to efficiently reach the eyes 8 of the observer outdoors or indoors with the image light from the image projection device 48. According to this, even if the intensity (luminance) of the image light from the image projection device 48 is reduced, the observer can accurately recognize the image and obtain information. In other words, by further reducing the output of the image projection device 48, it is possible to realize an information display system with lower power consumption.

<One-way transparent sheet: reflective type>
Next, the configuration and operation of the transparent sheet 51 will be described with reference to FIG. Here, the S polarization of sunlight incident on the wind glass 220 from an oblique direction is reflected, and the P polarization is transmitted to the transparent sheet 51. The transparent sheet 51 is composed of a polarizing plate 57 that transmits S waves, a transparent diffusion sheet material 55, and a retardation plate 58. The transparent sheet 51 is a film stretched while melting a thermoplastic polymer in which nanoparticulate zirconium or nanoparticulate diamond having a large refractive index is dispersed, for example, "Kaleidoscreen" manufactured by JXTG Energy Co., Ltd. is used (the above-mentioned patent). (Refer to Reference 3), it is transparent when the image is not displayed, and does not prevent the observer from monitoring the scenery of the outside world (outside the store). On the other hand, when the image is displayed, the image light is diffused and reflected. As a result, it is possible to realize a so-called unidirectional display in which a viewer inside or outside the store (space) can visually recognize the video information. At this time, if the haze degree (HAZE) defined by the ratio of the diffusion transmittance and the parallel light transmittance of the transparent sheet 51 is 10% or less, there is no practical problem, but preferably 4% or less.

Since the image light from the image projection device 48 is S-polarized, it scatters inside the transparent diffusion sheet material 55 described above and emits light toward the observer in a state where the reflectance is high when the light is obliquely incident. On the other hand, a part of the image light is dispersed in the polarization direction due to scattering, diffuses and transmits through the transparent diffusion sheet material 55, and is emitted toward the window glass 220. Since the difference in refractive index is small on the incident surface of the wind glass 220, the level of the double image generated by the reflected light is low. On the other hand, the intensity of the reflected light generated on the exit surface (the surface in contact with the outside world) of the wind glass 220 has a large reflectance because most of the S polarization component is present. The image light reflected on this surface passes through the polarizing plate 57 again after being reflected and is absorbed, so that it does not return to the observer side. Therefore, the light intensity of the double image generated by the reflected image of the wind glass 220 can be significantly reduced, and the image quality is greatly improved. Similarly, it goes without saying that the same effect can be obtained by attaching the above-mentioned transparent sheet 51 to the combiner instead of the wind glass 220 as the image reflecting surface.

The transparent sheet 51 described above allows the P-polarized sunlight component that has passed through the windglass 220 under predetermined conditions in the daytime (in the combiner method, the combiner also passes after that) to be provided in the information display system and the light direction conversion provided on the upper surface thereof. By absorbing the light in front of the panel 54 and the protective cover 50, it is possible to prevent the light from returning to the liquid crystal display panel and the polarizing plate.

<One-way transparent sheet: transparent type>
FIG. 12 shows the configuration of the transparent sheet 51'that diffuses the image luminous flux to the outside of the vehicle or the outside of the vehicle. A polarizing plate 57 that transmits P waves and a retardation plate 58 are provided on the incident surface of the image light flux of the transparent diffusion sheet material 55, and the image light flux reflected by the transparent diffusion sheet material 55 is indoors (a space in which an information display device is installed). ) To prevent it from returning. As a result, the observer does not have any trouble with the image projected on the window glass 220'. The optimum phase difference of the retardation plate 58 provided between the polarizing plate 57 and the transparent diffusion sheet material 55 should be selected according to the diffusion characteristics of the transparent diffusion sheet. If the diffusion angle is large, λ / It is better to be close to 4, and when the diffusion angle is small, better conversion characteristics can be obtained by combining with a λ / 8 plate or the like.

Further, by providing the surface of the above-mentioned polarizing plate with an antireflection coating having an increased reflectance of a specific polarized light instead of the above-mentioned transparent diffusion sheet material 55, the reflectance of the image light beam can be increased, and at the same time, the wind glass 220. It was confirmed that the intensity of the double image generated by the reflected image of the above can be significantly reduced, that is, the same effect as the above-mentioned technique can be obtained.

Further, instead of the transparent diffusion sheet material 55 described above, for example, PDLC (Polymer Dispersed Liquid Crystal) of Suntech Display Co., Ltd. is used, and in the image display state, the image light is dispersed without applying a voltage, and the image is not displayed. Then, it is advisable to substitute a transparent sheet by applying a voltage to make it transparent.

<Light direction conversion panel>
FIG. 13 is a schematic explanatory view for explaining the principle of the optical direction conversion panel 54 provided on the upper surface of the image projection device 48 described above, which constitutes a part of the information display system of the present embodiment. The luminous flux from the light guide body 17 of the light source device 101 described above is incident from the incident surface (lower surface in the figure) of the light direction conversion panel 54, and is due to the lens action of the linear Fresnel lens provided on the exit surface (upper surface in the figure). The light flux is refracted in the desired direction θ3. At this time, the desired direction θ3 is uniquely derived from Snell's law by the angle of incidence θ2 of the luminous flux on the Fresnel lens, the Fresnel angle θ0 of the Fresnel lens, and the refractive index n of the base material. As a result, the substantially parallel light flux from the light guide can be given directivity in a desired direction. That is, the image light, which is the light from the liquid crystal display panel 52 constituting the image projection device 48, is provided on the window glass 220 described below without being visually recognized by an observer inside or outside the store (space). Head to the transparent sheet 51. Originally, after that, the image light is reflected and diffused in one direction by the transparent sheet 51, and the reflected image is visually recognized by the observer. That is, the light direction conversion panel 54 does not allow the image light from the image projection device 48 (see FIG. 2 or 3) to be directly recognized from the space, and therefore, the observer in the store. Only the reflected image by the reflected light will be monitored by the observer without getting in the way. By providing a light-absorbing paint or pigment on the connecting surface 88 of the Fresnel lens, the generation of light other than the light flux traveling in a desired direction is suppressed. As a result, unnecessary light is not mixed with the image light reflected by the wind glass 220, so that the imaging performance is not impaired.

<Protective cover>
FIG. 14 is a cross-sectional view showing a schematic configuration of the protective cover 50 provided on the upper surface of the optical direction conversion panel 54. A black stripe 59 is provided on a part of the substantially transparent base material 56 on the light emitting side. In order to reduce the surface reflection of external light including sunlight, it is preferable to use a paint containing carbon black as the black paint for the black stripe 59. Further, by providing an antireflection film on the portion where the black stripe is not provided in order to suppress surface reflection, the external light reflection on the surface of the protective cover 50 is significantly reduced, and the hindrance due to the external light reflection is reduced. On the other hand, in order to enhance the light-shielding performance against sunlight, it is preferable that the antireflection film has a property of reflecting near-infrared light and infrared light.

On the other hand, on the light incident side of the substantially transparent base material 56, a film or film 50a that absorbs or reflects the P wave component of the solar luminous flux is formed or adhered. As a result, since the P wave component of sunlight does not enter the image projection device 48, the reliability regarding light resistance and heat resistance is significantly improved. On the other hand, since it also has the characteristics of a filter that selectively transmits the S-polarized image light output from the image projection device 48, the contrast performance of the obtained image is significantly improved.

Since the image source constituting the image projection device 48 described above is a liquid crystal panel, when the observer wears polarized sunglasses, a problem occurs in which a specific polarization is blocked and the image cannot be seen. .. In order to prevent this, as described above, the film or film 50a is used to absorb or reflect the P wave component of the solar luminous flux provided on the light incident side surface of the protective cover 50 provided on the light emitting side of the image projection device 48. A wave plate 50b such as a λ / 4 plate, a λ / 8 plate, or a λ / 16 plate is arranged between the materials 56. By providing the wave plate 50b, it is preferable to align the polarization directions of the luminous flux in a specific direction, set the image light as the optimum polarization angle, and shift the polarization direction of the polarized sunglasses and the desired amount of polarization axis.

On the other hand, even with the same polarized light, if the absorption axis is rotated and the absorption axis of the polarizing plate on the exit side of the liquid crystal panel is shifted by 30 degrees or more with respect to the absorption axis of polarized sunglasses, the absorption becomes about 50%, so that the image cannot be seen. Can be resolved.

Further, when the polarization axis is rotated to approach circularly polarized light, the polarization axis of the image light from the information display system is rotated from S-polarized light. For this reason, the reflectance of the wind glass 220 is lowered and the brightness of the image is lowered. Therefore, it is preferable to balance the two.

According to the present embodiment described in detail above, various information can be displayed inside or outside by using the show window 220, and the utilization efficiency of the show window can be remarkably improved. In addition to displaying high-quality images at high resolution, an information display system that can improve the utilization efficiency of the light emitted from the light source and significantly reduce power consumption is realized. Further, when displaying a larger image, a plurality of relatively inexpensive liquid crystal display panels are combined as an image display element 52 constituting the image projection device 48 together with the light source device 101, and the joint portion is continuously integrated. It is also possible to adopt a large-sized liquid crystal display panel 52. In this case, the power consumption is also significantly reduced by reflecting and diffusing the light flux from the light source device 101 described above in one direction toward the transparent sheet 51 provided on the wind glass 220 by the transparent sheet 51. However, it is possible to display a larger image information.

In the above description, the information display system is applied to a store which is a space partitioned by a show window which is a transparent member such as glass, and the show window 220 is used in one direction with respect to the inside or the outside. Although the example to be displayed has been described, the present invention is not limited to such an example. That is, in the information display system of the present invention, if a predetermined space is partitioned by using a transparent member such as glass, the information display system displays in one direction with respect to the inside or the outside by using the transparent member that partitions the space. This is possible, and other examples of information display systems will be described below.

<Vehicle information display system>
15 and 16 show a vehicle information display system in which the information display system of the above-described embodiment is applied to a vehicle such as an automobile, a train, or an aircraft, and in particular, when the information display system is mounted on a commercial vehicle such as a bus or a train. It is an external view of. On the front part of the driver's seat of the vehicle body 1, a windshield 6 as a translucent projected member for projecting and displaying image light, a rear glass 6'(not shown), a side glass 6 "etc. There is also "shield glass"). In particular, the windshield 6 has a different inclination angle with respect to the vehicle body depending on the type of vehicle. The inventors also investigated this radius of curvature in order to realize an optimum virtual image optical system. As a result, in the front glass 6 of a bus, a railroad vehicle, etc., the radius of curvature Rh in the horizontal direction horizontal to the ground plane of the vehicle and the radius of curvature Rv in the direction perpendicular to the horizontal axis have the following relationship and are in the horizontal direction. It was found that the radius of curvature Rh of is close to a horizontal surface in many cases.
Rh> Rv

This vehicle information display system has a windshield 6, a rear glass 6', and / or a side glass 6 "as a projecting member that is a translucent member that partitions the space inside the vehicle and constitutes a part of the vehicle. It is used to display video information in one direction inside or outside the vehicle, and when the driver drives his own vehicle, the driver and passengers in the vehicle are made to monitor the video information, while the other As a result, the driver and passengers appropriately display necessary information in a display area such as the windshield 6 in the vehicle, and the video information can be displayed to the outside of the vehicle. It can be monitored, but on the other hand, the information cannot be monitored from the outside of the vehicle, or to the outside of the vehicle via the rear glass 6'or the side glass 6'(which may include the windshield 6). On the other hand, video information can be displayed, and this displayed information can be monitored from the outside, but it cannot be monitored from inside the vehicle, without preventing the driver or passengers from monitoring the outside landscape. , Does not interfere with driving.

Further, in the information display system for vehicles, since the vehicle itself is exposed to natural light including sunlight, it is necessary to deal with such sunlight. Natural light such as sunlight is as shown in FIG. Not only light in a wide wavelength range from ultraviolet rays to infrared rays, but also two types of polarization directions (hereinafter referred to as S-polarized light and P-polarized light), which are light in the vibration direction perpendicular to the traveling direction of light and light in the horizontal direction. It exists in a state of being mixed with the light of (described). In particular, in a region where the angle of incidence on the windshield 6 exceeds 50 degrees, the reflectance on the glass surface differs depending on the S-polarized light, the P-polarized light, and the incident angle, as shown in FIG.

Therefore, in this embodiment, based on the above-mentioned findings by the inventor, that is, considering that most of the sunlight entering through the front glass 6 is a P-polarized light component, the sunlight entering the information display device is included. In order to suppress the outside light, it is particularly effective to reduce the P wave component, and in addition, it should be emitted from the information display device and reflected in the vehicle to be recognized by the driver or passenger who is the observer. It was confirmed that it is effective to use the S-wave component as the image light.

<Specific configuration of vehicle information display system 1>
Subsequently, with reference to FIGS. 19 and 20, a vehicle information display system to which the information display system according to the present embodiment is applied to a vehicle and a specific configuration thereof will be described in detail.

FIG. 19 shows an external landscape in which the driver applies the information display system according to the present embodiment to the vehicle and monitors the video information through the windshield 6 which is a transparent projected member forming a part of the vehicle. The overall configuration of the vehicle information display system displayed in a part of is shown. Here, the windshield 6 is divided into a plurality of regions, and the image light from the image projection device 48 is diffused and reflected by the windshield 6 in a part of the regions (in this example, the upper part of the windshield 6). The reflected image is directly monitored by the driver and passengers in one direction. As a result, the driver and passengers can appropriately display and monitor necessary information in the display area of the windshield 6, but on the other hand, the information cannot be visually recognized from the outside of the vehicle. ..

In this vehicle information display system, as shown in FIG. 19, the image projection device 48 details, for example, high-resolution map information (image of a large-scale high-resolution image display device) from a smartphone 300 or the like below. However, via the light direction conversion panel 54 and the protective cover 50 (hereinafter, the light source device 101, which is a backlight device constituting the information display system of this embodiment, the image projection device 48, the light direction conversion panel 54, and the protective cover). 50 is collectively referred to as an “information display device” 100), which is projected onto the inner surface of the windshield 6 and is viewed by a monitor (driver) via a transparent sheet 51 provided on the surface of the windshield 6. An image is displayed on the windshield 6 by reflecting the light toward the eye 8. In this example, an example is shown in the case of using a smartphone 300, which is a high-performance mobile terminal device equipped with a navigation function that provides map information and the like, and the display screen from the smartphone 300 is a wired connection terminal. It is possible to display the video by inputting it via Bluetooth (registered trademark) or wirelessly such as Wifi (registered trademark), so that the driver can display the vehicle information display system. It can be used to monitor high-resolution video information. Although not shown here, the smartphone is a CPU (Central Processing Unit), a work memory, various solid-state memories such as a RAM and a ROM having a function as an information storage / storage means, and the like, like the above-mentioned image projection device 48. It is natural that the control unit is provided with a control unit configured by the above, and has a function of generating a necessary image and displaying it on the display device (liquid crystal display).

Further, a more specific configuration of the vehicle information display system will be described with reference to FIG. The image display element 52 constituting the image projection device 48 of the information display device 100 is composed of, for example, a relatively large liquid crystal display panel having a screen size of more than 6 inches. In general, since the radius of curvature of the windshield 6 is often partially different, non-uniform (longitudinal and horizontal) distortions occur in the displayed image depending on where the image is reflected. Therefore, distortion correction is required to obtain a correct image when the reflected image is viewed from the monitoring direction. A panel resolution of 1280 x 720 dots or more is required to perform correction at a level that does not cause a problem in practical use by this distortion correction.

Further, the image projection device 48 includes the above-mentioned liquid crystal display panel 52 and a light source device 101 constituting the light source. In FIG. 20, the light source device 101 is shown above the liquid crystal display panel 52. ..

As shown in FIG. 20, the liquid crystal display panel (element) 52 obtains a highly directional illumination luminous flux by a light source device 101 which is a backlight device, and modulates the image light according to an input image signal. Is emitted toward the transparent sheet 51 provided on the windshield 6. Further, in FIG. 20, the vehicle information display system includes a liquid crystal display panel 52 constituting the image projection device 48, an optical direction conversion panel 54 for controlling the directional characteristic of the luminous flux 30 emitted from the light source device 101, and an optical direction conversion panel 54. , It is configured to be provided with a narrow angle diffuser (not shown) as needed. That is, polarizing plates are provided on both sides of the liquid crystal display panel 52, and video light having a specific polarization is emitted by modulating the light intensity with the video signal. As a result, a high-resolution image (an image of a large-scale high-resolution image display device) from a smartphone 300 or the like is projected toward the windshield 6 via the optical direction conversion panel 54, and a transparent sheet 51 provided on the surface thereof. It reflects toward the eyes 8 of the observer (driver) through.

As shown in FIG. 20, the image projection device 48 constituting the information display device 100 includes a light source device 101, a liquid crystal display panel 52, and the like, and includes the light source device 101 of the image projection device 48. The operation has already been shown as Example 1 and Example 2 of the image display device in FIGS. 3 to 7 above, and although not described in detail here, almost all the light generated by the LED is taken out as parallel light. It is possible to improve the utilization efficiency of the generated light, further improve its uniform lighting characteristics, and at the same time, it is manufactured in a small size and at low cost including a modularized S-polarized light source device. It becomes possible to do.

Although not shown here, by adopting the lenticular lenses shown in FIGS. 8 to 10, the image light from the image projection device 48 can efficiently reach the eyes 8 of the observer outdoors or indoors. This makes it possible to realize a vehicle information display system with low power consumption in which the output of the image projection device 48 is further reduced.

Further, the optical direction conversion panel 54 provided on the lower surface of the image projection device 48 described above is the same as that already described in FIG. 13 and the description related thereto, and its configuration and operation will not be described in detail here. However, the image light, which is the light from the liquid crystal display panel 52 constituting the image projection device 48 of the information display device 100, is transparent provided on the front glass 6 without being visually recognized by the driver or passengers inside the vehicle. The image light is directed to the seat 51, and then the image light is reflected and diffused in one direction by the transparent sheet 51, and the reflected image is visually recognized by the driver. That is, due to the light direction conversion panel 54, the image light from the image projection device 48 itself is not directly visible from the inside of the vehicle, and therefore does not interfere with driving, and is due to the reflected light. Only the reflected image will be monitored by the driver and passengers.

Further, the protective cover 50 which is arranged in contact with the ceiling surface of the vehicle and is provided on the upper surface of the above-mentioned optical direction conversion panel 54 is the same as that already described in FIG. 14 and the related description above, and here, the same. Although the configuration and operation will not be described in detail, the vehicle information display system will reduce the hindrance caused by the reflection of external light, especially when the driver drives the vehicle.

In addition, the S polarization of sunlight incident on the windshield 6 from an oblique direction is reflected, and the P polarization is transmitted to the transparent sheet 51. As already described in FIG. 11 and related descriptions above, the transparent sheet 51 is composed of a polarizing plate 57 that transmits S waves and a transparent diffuse sheet material 55, and when no image is displayed, the transparent sheet 51 is composed of a polarizing plate 57 that transmits S waves. It is transparent and does not prevent the driver from monitoring the scenery of the outside world (outside the vehicle). On the other hand, when displaying the image, the image light is diffused and reflected so that the driver and passengers can see the image information. It is possible to realize the display of directionality. At this time, if the haze degree (HAZE) defined by the ratio of the diffusion transmittance and the parallel light transmittance of the transparent sheet 51 is 10% or less, there is no practical problem, but preferably 4% or less. On the other hand, the HAZE of wind glass for automobiles is 2% or less.

On the other hand, since the image light from the image projection device 48 of the information display device 100 is S-polarized, the transparent diffusion sheet material 55 constituting the transparent sheet 51 described above is in a state of high reflectance when obliquely incident (FIG. It scatters inside (see 11) and emits toward the observer. On the other hand, a part of the image light is scattered in the polarization direction, diffuses and transmits the transparent diffusion sheet material 55, and is emitted toward the windshield 6. Since the difference in refractive index is small on the incident surface of the windshield 6, the level of the double image generated by the reflected light is low. On the other hand, the intensity of the reflected light generated on the exit surface (the surface in contact with the outside world) of the windshield 6 has a large reflectance because most of the S polarization component is present. After being reflected, the image light reflected by this surface passes through the polarizing plate 57 (see FIG. 11) and is absorbed, so that it does not return to the observer side. Therefore, the double image generated by the reflected image of the windshield 6 is not generated, so that the image quality is greatly improved. Similarly, it goes without saying that the same effect can be obtained by attaching the above-mentioned transparent sheet 51 to the combiner instead of the windshield 6 as the image reflecting surface.

According to the transparent sheet 51 described above, as is clear from FIGS. 19 and 20 above, the P-polarized solar component that has passed through the front glass 6 under predetermined conditions in the daytime (in the combiner method, the combiner is also subsequently combined). Passage), the image projection device 48 including the light source device 101 and the liquid crystal display panel 52, the information display device 100 including the light direction conversion panel 54, and the light direction conversion panel 54 and the protective cover provided on the upper surface thereof. By absorbing light in front of 50, it is possible to prevent the liquid crystal display panel and the polarizing plate from returning to each other.

In the above example, a reflective transparent sheet 51 is used as the unidirectional transparent sheet 51 provided on the windshield 6, but instead of this, the transmissive transparent sheet 51 described in FIG. 12 above is used. By adopting the transparent sheet 51', it is possible to diffuse the image luminous flux in one direction, that is, to the outside of the vehicle. In that case, a polarizing plate and a retardation plate that transmit P waves are provided on the image luminous flux incident surface of the transparent diffusion sheet material 55 (see FIG. 12) constituting the transparent sheet 51'and reflected by the transparent diffusion sheet material 55. It prevents the image luminous flux from returning to the room (the space where the information display device 100 is installed). As a result, the driver does not have any trouble in driving due to the image projected on the windshield 6. The optimum phase difference of the retardation plate 58 provided between the polarizing plate 57 and the transparent diffusion sheet material 55 should be selected according to the diffusion characteristics of the transparent diffusion sheet. If the diffusion angle is large, λ / 4 It is better to be close to, and when the diffusion angle is small, better conversion characteristics can be obtained by combining with a λ / 8 plate or the like.

According to the vehicle information display system provided with the information display device 100 described in detail above, as shown by the arrows in FIGS. 19 and 20, the image of the upper region of the windshield 6 which is a transparent member for partitioning the interior space of the vehicle. A large high-resolution image projection device 48 is provided at a position corresponding to the display area (ceiling surface in FIG. 19), and the displayed image is reflected by the windshield so that the reflected image can be directly transmitted to the driver or passengers. It becomes possible to monitor.

<Specific configuration of vehicle information display system 2>
In the above, an image is displayed by the information display device 100 of the present embodiment including the image projection device 48, the optical direction conversion panel 54, etc. by using the windshield 6 including the windshield 6 and the side glass 6 ”that partition the vehicle space. Although the information display system for vehicles has been described, the present invention is not limited to this, and further, an image is displayed by using a windshield, or a head-up display (HUD) type information display device (hereinafter referred to as “HUD”). It is also possible to mount and use a "HUD device") at the same time, and an example thereof will be described below.

FIG. 21 shows an example in which a vehicle information display system is mounted on an ordinary passenger car instead of the above-mentioned large vehicle. In FIG. 21, a part of the windshield 6 (upper part of the steering wheel 43) and An image is displayed in one direction toward the inside or outside of the display vehicle by the information display device 100 including the image projection device 48 and the optical direction conversion panel 54 described above on a part of the side glass 6 ”.

Further, as the HUD device, a known general device can be adopted, and here, as an example thereof, the outline thereof will be described below.

FIG. 22 is a schematic configuration diagram showing the HUD device 700 including its peripheral device configuration. Here, in order to form a virtual image V1 in front of the own vehicle in the line of sight (eye point) of the driver 8, the projected member Various information reflected by 6 (inner surface of the windshield) is diffusely reflected inside the vehicle by the transparent sheet 51 provided on the windshield 6 and displayed as a real image.

The HUD device 700 described above includes a video display device 704 that generates video light for displaying information, and a light source device 710 that supplies light to the video display device 704. In order to control the diffusion distribution of the image light from the image display device 704, it can be controlled in one direction by providing a lenticular lens between the light source device 710 and the image display device 704 described above and optimizing the lens shape. Further, the image luminous flux from the HUD device 700 is emitted from the opening (not shown) toward the windshield 6.

Further, the HUD device 700 includes a control device 740 that controls the backlight. The optical components including the image display device 704 and the backlight reflect the display image of the image display device 704 on the transparent sheet 51 attached to the windshield 6 and simultaneously diffuse the display image toward the driver's line of sight 8. The image display device 704 includes, for example, an LCD (Liquid Crystal Display) having a backlight.

The illustrated control device 740 constituting the HUD device has the speed limit and the number of lanes of the road corresponding to the current position where the own vehicle is traveling from the navigation system 761, and the movement schedule of the own vehicle set in the navigation system 761. Various information such as a route is acquired as foreground information (that is, information displayed in front of the own vehicle by the above-mentioned virtual image). Further, the driving support ECU 762 is a control device for realizing driving support control by controlling the drive system and the control system according to the obstacle detected as a result of the monitoring by the peripheral monitoring device 763. Such driving support control includes well-known techniques such as cruise control, adaptive cruise control, pre-crash safety, and lane keeping assist. The illustrated peripheral monitoring device 763 is a device that monitors the situation around the own vehicle, and as an example, a camera that detects an object existing around the own vehicle based on an image taken around the own vehicle, or It is an exploration device that detects objects existing around the own vehicle based on the result of transmitting and receiving exploration waves.

The control device 740 of the HUD device described above acquires information from such a driving support ECU 762 (for example, the distance to the preceding vehicle, the direction of the preceding vehicle, the position where an obstacle or a sign exists, etc.) as foreground information. Further, an ignition (IG) signal and own vehicle state information are input to the control device 740. Of these information, the own vehicle status information is information acquired as vehicle information and does not require high-resolution display, for example, the remaining amount of fuel of the internal combustion engine, the temperature of the cooling water, etc. are predetermined. It contains warning information indicating that the abnormal condition has occurred. In addition, the operation result of the direction indicator, the traveling speed of the own vehicle, and the shift position information are also included. The control device 740 described above is activated when an ignition signal is input. The projected member 6 may be a member to which information is projected, and may be a combiner in addition to the windshield described above, and forms a real image in front of the own vehicle in the driver's line of sight 8. Anything that can be visually recognized by the driver will do.

Subsequently, FIG. 23 shows an example of the arrangement in the cockpit of the automobile in which the information display device 100 and / or the HUD device 700 of this embodiment including the above-mentioned image projection device 48 and the transparent sheet 51 is arranged. FIG. 23A shows a system corresponding to an automobile having a steering wheel arranged on the left side, and FIG. 23B shows a system corresponding to an automobile having a steering wheel arranged on the right side. In the HUD image display area (1a) in the figure, the image information is reflected and displayed by the windshield 6 using the HUD device 700 shown above, and corresponds to the image display area (1b) (corresponding to the area where the transparent sheet 51 is attached). The information display device 100 is used to reflect the image information on the windshield 6 and have the driver monitor the reflected image. At that time, as shown in FIG. 23, the image display area (1b) is on the upper part of the windshield 6, and the HUD image display area (1a) is outside the vehicle for the driver, for example, in the range where the bonnet of the own vehicle is monitored. It would be preferable to set it in a range or area that does not interfere with the monitoring of the landscape.

As shown in FIG. 23, the above-mentioned information display device 100 is on the ceiling surface of the vehicle, while the HUD device 700 is inside the dashboard 47 between the windshield 6 and the steering wheel 43, from the windshield 6 to the HUD device 700. Are arranged toward the steering wheel 43 in this order. As a result, when the driver drives his / her own vehicle, the information display device 100 displays a large-sized high-resolution image on the external landscape monitored through the windshield 6, that is, a part of the windshield 6. By reflecting the image of the display device on the windshield 6, the driver or passenger can monitor the reflected image, or the information from the HUD device 700 can be displayed as needed. The system can be provided.

That is, the image display area (1b) in which the transparent sheet 51 is attached to the window glass 6 reflects the image light from the information display device 100 and causes the driver to monitor it. At that time, the augmented reality can be realized in a pseudo manner by superimposing the image display area (1b) on the landscape monitored by the driver while driving, for example. The image projected at this time is preferably set in a range or area that does not interfere with the monitoring of the scenery outside the vehicle for the driver.

The rearview mirror 71 shown in FIG. 23 is provided with a camera 72 for monitoring the driver's condition and the inside of the vehicle. For example, the image light from the information display device 100 described above is adapted to the height of the driver's eyes. It would also be possible to control the emission direction of.

<Modification example of vehicle information display system: external display>
According to the embodiment described in detail above, when the driver drives his / her own vehicle, necessary image information is transmitted to the inside of the vehicle through the windshield 6 as a projected member which is a shield glass constituting the vehicle. It is possible to display and monitor the driver and passengers in one direction with high resolution. At that time, the information cannot be monitored from the outside of the vehicle. However, the vehicle information display system according to the present invention is not limited to the above-described embodiment, and it is also possible to display video information to the outside of the vehicle. That is, in the same manner as above, the image information is displayed to the inside or the outside of the vehicle not only through the windshield 6 described above but also through the rear glass 6'and the side glass 6'which are shield glasses. It is possible to do.

For example, in the system of this embodiment, it is possible to display information indicating the state of a vehicle such as an "empty vehicle" on a part of the windshield 6 of a taxi, and further on the rear glass 6'or the side glass 6 ". Alternatively, it is also possible to display information such as other information promotion / advertisement to the outside of the vehicle. Also, in a vehicle such as a bus or a train, information such as the route or destination can be displayed on the windshield. It is also possible to display the information on the windshield, the side glass, etc. in one direction to the outside of the vehicle. The configuration of the information display system for the vehicle when the information is displayed to the outside will be described below.

FIG. 24 shows a system in which necessary image information is displayed and monitored in one direction with high resolution from the outside of the vehicle via a windshield 6 as a projected member, more specifically, Here, an example of displaying the status of a taxi (such as "empty car") on the windshield of a taxi is shown. In this example, in the configuration shown in FIG. 24, the image light from the information display device 100'is diffused by the windshield 6 as a transparent sheet 51'(see FIG. 12) provided on the surface of the windshield 6. -Transparently, the image is transparently displayed outside the vehicle as shown by an arrow in FIG. 12, and can be monitored by, for example, a pedestrian. As a result, the driver and passengers can display the necessary information on the windshield 6 relatively large with respect to the outside of the vehicle, but the display may interfere with the monitoring of the scenery outside the vehicle to be monitored from inside the vehicle. It does not interfere with the driver's driving.

Further, instead of the transparent diffusion sheet material 55 (see FIG. 12) of the transparent sheet 51'described above, an antireflection coating having an increased reflectance of a specific polarized light is provided on the back surface of the above-mentioned polarizing plate to reflect the image light beam. The rate can be increased, and at the same time, the intensity of the double image generated by the reflected image of the front glass 6 can be significantly reduced. That is, it was confirmed that the same effect as the above-mentioned technique can be obtained.

Further, instead of the transparent diffusion sheet material 55 of the transparent sheet 51'described above, for example, PDLC (Polymer Dispersed Liquid Crystal) of Suntech Display Co., Ltd. is used to disperse the image light without applying a voltage in the image display state. In the state where the image is not displayed, a voltage may be applied to make the transparent state, which may be used as a substitute for the transparent sheet.

Similar to the above, the transparent sheet 51'is composed of a polarizing plate 57 that transmits S waves and a transparent diffusion sheet material 55. Here, nanoparticle zirconium and nanoparticle diamond having a large refractive index are dispersed. By using a film stretched while melting the molten thermoplastic polymer, for example, "Kaleidoscreen" manufactured by JXTG Energy Co., Ltd. (see Patent Document 2), it is transparent when no image is displayed, while it is transparent. When displaying an image, the image light is diffused and transmitted. As a result, the video information can be displayed to the outside without causing the driver or passengers to visually recognize the video information and hindering the monitoring of the scenery outside the vehicle.

The action of the transparent sheet 51'in this case will be described. The transparent sheet 51'is composed of a polarizing plate 57, a transparent diffusion sheet material 55, and a retardation plate 58, and similarly to the above, the S polarization reflects sunlight incident from an oblique direction, while the S polarization reflects the other. By transmitting P-polarized light, the illuminance of sunlight is reduced. At this time, a part of sunlight is absorbed by the polarizing plate by rotating the polarization axis of P-polarized light by the retardation plate 58. As a result, the damage that the image projection device 48 receives due to sunlight can be dispersed.

On the other hand, the image light diffused outside the vehicle by the action of the transparent diffusion sheet material 55 (see FIG. 12) is reflected by the rear glass 6'and returns to the inside of the vehicle. This light obstructs the driver's field of vision and hinders driving. Therefore, in this embodiment, the retardation plate 58 is arranged between the rear glass 6'and the polarizing plate 57, and the reflected light is absorbed by the polarizing plate so that the information by the image light can be visually recognized by the driver and passengers in the vehicle. It is displayed in one direction toward the outside of the vehicle. At that time, the information obtained by the video light does not interfere with the driver or passengers in the vehicle from monitoring the scenery outside the vehicle and does not interfere with the driving. If the haze degree (HAZE) defined by the ratio of the diffusion transmittance and the parallel light transmittance of the transparent sheet 51 described above is 10% or less, there is no practical problem, but preferably 4% or less. On the other hand, the HAZE of wind glass for automobiles is 2% or less.

As described above, the display of information to the outside of the vehicle using the windshield 6 and a part of the shield glass such as the rear glass and the side glass is particularly the above-mentioned "empty vehicle" indicating the empty state of the taxi. It would be suitable for displaying this information to pedestrians on the street. Further, as described above, the vehicle information display system according to the present embodiment not only displays video information in one direction on the windshield, but also in a large vehicle such as a bus or a train. Also, various information including advertisements, advertisements, notifications, etc. can be obtained by using the projected members such as the rear glass 6'and the side glass 6'(see FIGS. 15 and 16) which are the shield glasses constituting the vehicle. It is also possible to display. The following describes the configuration of the vehicle information display system and its operation when displaying information to the outside of the vehicle.

As another example, FIG. 25 shows information as a projected member constituting a part of the vehicle, for example, displaying information to a pedestrian or the like outside the vehicle through the rear glass 6'constituting the vehicle. Is. As a result, the driver and passengers can monitor the necessary information on the windshield 6 described above (see FIG. 21 and the like), but at the same time, the information can be displayed outside the vehicle by the rear glass 6'. The driver and passengers cannot monitor the information displayed to the outside, and therefore do not obstruct the driver's field of vision. That is, the display of information outside the vehicle does not prevent the driver or passenger inside the vehicle from monitoring the outside landscape.

In this example, an image display area (1) in which the information display device 100'is arranged above the rear glass 6', which is a projected member forming a part of the vehicle, and the image light is set on the entire surface or a part of the rear glass 6'. Video information is displayed by projecting toward 1e).

In this example as well, it is natural that the transparent sheet 51'shown in FIG. 12 described above is provided in the image display area of the rear glass 6'. In addition, the projected member that displays video information in one direction toward the outside of the vehicle is not limited to the windshield 6 and the rear glass 6'described above, and other, for example, the side glass 6 that constitutes the side surface of the vehicle. It is also possible to use (see FIGS. 15, 16, 21, etc.), in which case, although not shown here, a member in the vicinity of the side glass 6 "(eg, an adjacent ceiling surface or window frame). It is natural that the information display device 100'is arranged in a part or the like), and the transparent sheet 51'shown in FIG. 12 is provided in the image display area (1d) of the side glass 6'. Displaying information on the side glass 6 ”may be suitable for displaying a message such as“ Thank you for waiting ”or“ Please board ”to passengers on the street, for example, in a taxi.

In addition, in the above-described example, the video information to be displayed is unidirectionally transmitted to the outside of the vehicle or to the outside of the vehicle via the windshield 6 and the rear glass 6'and the side glass 6'which are the projected members constituting the vehicle. The information display devices 100 and 100'displayed inside are described. However, the present invention is not limited to these, and for example, together with the information display device 100 that displays information inside the vehicle, the information is displayed outside the vehicle. It is also possible to appropriately combine the information display device 100'to display the information display device 100'. According to this, for example, when applied to a bus or train which is a public transportation system, the rear glass 6'or the side glass 6'or the side glass 6' It is possible to display various information including advertisements, advertisements, notifications, etc. to the public outside the vehicle (however, it can be controlled so that it is not visible from inside the vehicle), and it is effective information for the public. Can be displayed. Further, as described above, it is also possible to simultaneously mount and use a head-up display (HUD) type information display device 700.

In the above description, an example in which various images are displayed on the image display area in which the transparent sheet 51 is attached to the window glass 6 by the information display device 100 has been described. However, the present invention is not limited to this, and instead of the above-mentioned transparent diffusion sheet material 55 (see FIG. 12), an antireflection coating having an increased reflectance of a specific polarized light is applied to the surface of the above-mentioned polarizing plate. It was confirmed that the same effect as the above-mentioned technique can be obtained because the reflectance of the image light beam can be increased and the intensity of the double image generated by the reflected image of the wind glass 6 can be significantly reduced at the same time.

Further, instead of the transparent diffusion sheet material 55 (see FIG. 12) described above, for example, PDLC (Polymer Dispersed Liquid Crystal) of Suntech Display Co., Ltd. is used to absorb or reflect a specific polarized light on the image light incident side. By forming a sheet or film, the image light can be displayed inside and outside the vehicle by making it white without applying voltage in the image display state. When the image is not displayed, a voltage may be applied to make the transparent sheet as a substitute for the transparent sheet. When the driver needs to see the rear view, for example, when shifting to the reverse gear or when the driver's surveillance camera confirms that the viewpoint has been moved to the rear mirror or rearview mirror, a voltage is applied to a part of the PDLC. The entire surface or part of the PDLC is made transparent to ensure rear visibility. The above-mentioned sheet or film reduces the return of image light to the driver side so as not to interfere with driving.

Further, it is also possible to display the image from the above-mentioned HUD device 700 on the window glass 6 by using the information display device 100 including the above-mentioned image projection device 48 and the optical direction conversion panel 54, and an example thereof. It is shown in FIG. The configuration and operation of the HUD device 700 are the same as those shown in FIG. 22, and the configuration and operation of the information display device 100 are also the same as those shown in FIG. Also in this case, similarly to the above, it is possible to improve the utilization efficiency of the generated light, further improve the uniform illumination characteristics, and at the same time, the modularized S-polarized wave light source device. It is possible to manufacture the product in a small size and at low cost, including the above.

In addition, when displaying a larger image through the windshield 6 or the rear glass 6'or the side glass 6 "which is a projected member constituting the vehicle, the above-mentioned information display devices 100 and 100' are combined with the light source device 101. As the image display element 52 constituting the image projection device 48, it is also possible to adopt a large liquid crystal display panel 52 in which a plurality of relatively inexpensive liquid crystal display panels are combined and the joints are continuously integrated. In this case, the power consumption is also significantly reduced by reflecting and diffusing the light beam from the light source device 101 described above in one direction toward the transparent sheet 51 provided on the windshield 6 by the transparent sheet 51. However, a vehicle information display device capable of displaying a larger image information can be realized relatively easily and inexpensively.

Although various examples have been described in detail above, however, the present invention is not limited to the above-mentioned examples, and includes various modifications. For example, the above-described embodiment describes the entire system in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 ... Automobile (vehicle) body, 6 ... Windshield, 6'... Rear glass, 6 "... Side glass, 100 ... (Vehicle) information display device, 101 ... Light source device, 48 ... Image projection device, 52 ... Liquid crystal display panel (element) ), 50 ... protective cover, 51 ... unidirectional transparent sheet, 54 ... optical direction conversion panel, 55 ... transparent diffusion sheet material, 57 ... polarizing plate, 58 ... retardation plate, 300 ... smartphone.

Claims (21)

An information display system that displays an image in one direction with respect to the inside or outside of the space through a transparent projected member installed in the space.
An image projection device that is arranged inside the space and modulates the luminous flux from the light source to generate and project image light.
A transparent sheet provided on the inner surface of the display area set as a part of the projected member, and
A light direction conversion panel that converts the direction of the image light from the image projection device toward the transparent sheet in the display area is provided.
The transparent sheet includes a retardation plate, an absorption-type polarizing plate that absorbs a specific polarized light, and a transparent diffusion sheet material having a light diffusing effect, and the video light whose direction is changed by the light direction conversion panel is transmitted. An information display system that projects toward the inside or outside of the space. In the information display system according to claim 1,
In addition
An information display system including a lenticular lens that controls the diffusion distribution of image light. In the information display system according to claim 1,
The optical direction conversion panel is an information display system formed by a linear Fresnel lens. The information display system according to claim 1, wherein the space is partitioned by the transparent projected member, and the space is a store. In the information display system according to claim 1, the image projection device is an information display system configured by combining a plurality of liquid crystal display panels. An information display system for vehicles that uses a part of the transparent projected members that make up the vehicle as a display area and displays information inside or outside the vehicle.
An image projection device provided inside the vehicle that projects the image light of the information, and
A transparent sheet provided on the inner surface of the display area set as a part of the projected member, and
A light direction conversion panel that converts the direction of the image light from the image projection device toward the transparent sheet is provided.
The transparent sheet includes a retardation plate, an absorption-type polarizing plate that absorbs a specific polarized light, and a transparent diffusion sheet material having a light diffusing action.
A vehicle information display system that projects the image light whose direction is changed by the optical direction conversion panel toward the inside or the outside of the vehicle. In the vehicle information display system according to claim 6,
In addition
A vehicle information display system provided on one surface of the light direction conversion panel and provided with a protective cover for reducing surface reflection of external light. In the vehicle information display system according to claim 6 or 7.
The transparent sheet is a vehicle information display system that projects the image light whose direction is changed by the light direction conversion panel toward the inside of the vehicle. In the vehicle information display system according to claim 6 or 7.
The transparent sheet is a vehicle information display system that projects toward the outside of the vehicle by transmitting the video light whose direction is changed by the light direction conversion panel. In the vehicle information display system according to claim 6,
The optical direction conversion panel is an information display system for vehicles formed by a linear Fresnel lens. In the vehicle information display system according to claim 7.
The protective cover is a vehicle information display system including a polarizing film that absorbs or reflects polarized wave components from the outside of the vehicle. In the vehicle information display system according to claim 6,
The projected member is a windshield, which is an information display system for vehicles. In the vehicle information display system according to claim 12,
A vehicle information display system configured such that the windshield projects the image light toward the inside and the outside of the vehicle by using a plurality of the vehicle information display systems. In the vehicle information display system according to claim 12,
In addition
An information display system for vehicles that is equipped with a head-up display device. In the vehicle information display system according to claim 6,
The vehicle information display system in which the projected member is a rear glass or a side glass. In the vehicle information display system according to claim 15,
The rear glass or the side glass is configured to project the image light toward the outside of the vehicle by using one or more of the vehicle information display systems. system. In the vehicle information display system according to claim 6, the image projection device is a vehicle information display system configured by combining a plurality of liquid crystal display panels. An information display system that displays an image to the inside or outside of the space through a transparent projected member of the partitioned space.
An image projection device that is arranged inside the space and modulates the luminous flux from the light source to generate and project image light.
A transparent sheet provided on the inner surface of the display area set as a part of the projected member, and
A light direction conversion panel that converts the direction of the image light from the image projection device toward the transparent sheet in the display area is provided.
The transparent sheet includes a retardation plate, an absorbent polarizing plate that absorbs a specific polarized light, and a PDLC (Polymer Dispersed Liquid Crystal) sheet having a light diffusing effect, and has a transmittance of light with and without voltage applied. An information display system that changes the dispersion and projects the image light whose direction is changed by the optical direction conversion panel toward the inside and the outside of the space. In the information display system according to claim 18,
In addition
An information display system including a lenticular lens that controls the diffusion distribution of image light. In the information display system according to claim 18,
The optical direction conversion panel is an information display system formed by a linear Fresnel lens. The information display system according to claim 18, wherein the space partitioned by the transparent projected member is a store.

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