JP2010224292A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of forming different real images to be viewed at a display part provided on a back wall and in the air in front of it by utilizing a real mirror video image optical system and one display. <P>SOLUTION: The display device 1 includes: the display part which is turned to the observer side and provided in a back wall part and includes a first display area 21 to be directly viewed by an observer; a second display area 22 (object to be observed) which is included in the display part and includes display information; a wall part 3 which is arranged more on the observer side than the back wall 2 and partitions the space on the observer side of the second display area 22 and the space on the observer side of the first display area 21; and a real mirror video image forming optical system which includes a reflection mirror 8 arranged so as to face the second display area 22, is provided on the wall part 3, has a semi-transmissive base including a symmetry plane, and forms the real image of the second display area 22 at a plane symmetrical position to the symmetry plane of the virtual image of the second display area 22 by the reflection mirror 8 in the space on the observer side of the first display area 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a display device as information display means for a driver in a vehicle such as a vehicle.

  If it is possible to display an aerial image in the space in front of a display device such as an instrument panel of an automobile (that is, a driver (observer) side), it is considered that a new display mode of the image can be proposed. As an example, while driving a car, the driver sometimes looks at the instrument panel while watching the outside of the car in front of the windshield and checks the speed, engine speed, time display, etc. Rather than displaying an indication on the instrument panel when the speed is too high, it is better for the driver to bring up a display that alerts the empty space in front of the instrument panel. It is thought that it may be easier to draw the attention of people and may contribute to the prevention of traffic accidents.

  As a technique for forming an observation object such as a three-dimensional or two-dimensional object or an image as a real image in the air, an aerial image display device using a microlens array, for example, has been developed (see, for example, Patent Document 1). This utilizes a double imaging system such as erecting the two-dimensional image, and the optical device having the same size as the display surface for displaying the two-dimensional image can spatially parallel the two-dimensional image without distortion. It is possible to move. If it is such, compared with a normal lens, size reduction and thickness reduction of an optical device can be achieved, and it contributes also to size reduction of a display apparatus. However, with such a display device, a two-dimensional real image that looks like a three-dimensional image can be obtained. In addition, since this display device observes a real image formed using light refraction by the microlens array, an observer can see the image only from the front of the microlens array.

JP 2001-255493 A

  However, when an aerial image formation method using a microlens array is applied to a display device, both the object to be observed and the display surface of the display and devices are placed behind the microlens array when viewed from the observer. Because it is physically impossible to do so, microlens arrays are not suitable for such new display formats.

  On the other hand, the present inventor arranges the display unit and the object to be observed at spatially separated positions, and displays the actual image of the object to be observed by the display on the display unit and the real mirror image forming optical system on the observer's line of sight. A display device in which a mirror image exists simultaneously is proposed (Japanese Patent Application No. 2008-70415). That is, the observer can simultaneously observe the real mirror image of the object to be imaged in front of the display unit while observing the display unit on the back wall. For example, if only the display part is usually observed, and the real mirror image of the object to be observed is imaged in the space in front of the display part only when there is some trigger, nothing will happen Since an image appears in a space that should not be present, an image observation method that makes it easier to call the viewer's attention can be obtained.

  Specifically, a back wall, a display unit provided toward the viewer facing the back wall, a wall unit disposed closer to the viewer than the back wall, and a rear side of the wall unit An object to be observed, and a real mirror image forming optical system that is exposed on the wall and forms a real image of the object to be observed in a plane symmetrical position of the object to be observed in a space on the viewer side of the display unit. The mirror image forming optical system has a symmetry plane (also referred to as an element plane in the two-surface corner reflector array) that forms a real image of the object to be observed in a plane-symmetrical position on the wall portion. It is exposed and a real image can be observed from the viewpoint of an observer who is oblique to the symmetry plane.

  Here, the display unit can be used as a display unit of an image display device such as a liquid crystal display or a CRT display, or a display unit such as an instrument panel such as a mechanical device. What is necessary is just to arrange | position to the back wall provided in.

  In addition, the display device may be provided with a wall portion positioned closer to the observer than the back wall, with the wall portion facing up, down, left, or right, and a symmetrical plane in the real mirror image forming optical system on this wall portion. Is provided. Further, on the back side of the wall portion, an object to be observed for imaging a real mirror image edge by a real mirror image forming optical system is provided. A two-dimensional or three-dimensional object or video can be applied to the object to be observed. That is, the display unit and the object to be observed are configured separately. In both cases, if a display is created using an electronic display such as a liquid crystal display, at least two electronic displays are required, and further, a drive circuit and a control circuit need to be provided separately.

  Therefore, the present invention can use a real mirror image forming optical system and a single display to form another real image on the display unit provided on the back wall and in the air on the near side. An object of the present invention is to provide such a display device.

  The present invention provides a display unit that includes a first display region that is provided on the back wall and is directly visible to the viewer toward the viewer, and a second display region that is included in the display unit and includes display information ( An object to be observed), a wall portion that is disposed closer to the viewer than the back wall and separates the space on the viewer side of the second display region and the space on the viewer side of the first display region, A reflecting mirror disposed in the viewer-side space of the second display area so as to face the display area, a semi-transparent base provided on the wall and including a symmetry plane; A real mirror image forming optical system that forms a real image of the second display region at a plane symmetrical position with respect to the symmetry plane of the virtual image of the second display region by the reflecting mirror in the space on the viewer side of the display region; A display device comprising: is provided.

  In the present invention, the real mirror image forming optical system includes a two-surface corner reflector array including a plurality of two-surface corner reflectors arranged with a gap in the plane of symmetry of the base, and each of the two-surface corner reflectors includes two It consists of mirror surfaces that are orthogonal, and the line of intersection of the mirror surfaces is orthogonal to the plane of symmetry. In the second display area, a part of the light rays emitted from the second display area are incident on the line of intersection of the mirror surfaces via the reflector. It may be arranged so as to pass between the two-surface corner reflectors and reach the space on the viewer side of the first display area.

  Further, in the present invention, the real mirror image forming optical system includes a half mirror formed on the base and arranged as a symmetry plane, and the second display area in the space on the viewer side from the second display area. A plurality of retro-reflectors arranged at positions where the light reflected by the half mirror is retroreflected.

  According to the present invention, the display unit provided on the back wall part toward the viewer side, the wall unit disposed closer to the viewer side than the back wall, and the reflecting mirror disposed on the back side of the wall unit And a real mirror image forming optical system that is provided exposed on the wall portion and forms a real image of an object to be observed in a space on the observer side of the display unit, the display unit being A first display area that is directly visible and a second display area that is not directly visible to an observer who displays an object to form the real image on a single display. The observation object displayed on the display unit is reflected by the reflecting mirror, and further, through the real mirror image forming optical system, a real image of the observation object is formed in a space on the observer side of the display unit. While observing the display part on the back wall from the viewpoint of the observer obliquely with respect to the real mirror image forming optical system, It is possible to observe a real mirror image of the observed object to be imaged before simultaneously.

  Here, as the display unit, an appropriate display unit such as a display unit of an electronic display such as a liquid crystal display or a CRT display or a display unit of an instrument panel such as a mechanical device can be applied. The first display area As long as the second display region is manufactured in a single display device. When an electronic display is used, the first display area and the second display area can be formed on the screen of a single electronic display. What is necessary is just to arrange | position this display part in the back wall provided in the back position in the display apparatus of this invention. Further, in the display device of the present invention, it is only necessary that the wall portion positioned on the viewer side with respect to the back wall is disposed so that either the upper, lower, left, or right side faces, and the real mirror image forming optical system is disposed on the wall portion. A plane of symmetry is provided. Further, on the back side of the wall portion, the real mirror image optical system reflects the light from the observation object provided in the second display region for forming the real mirror image by the real mirror image image forming optical system. A reflecting mirror is provided that leads to A two-dimensional or three-dimensional object or video can be applied to the object to be observed.

  With such a display device, the display unit and the object to be observed can be created with a single display, and the display on the display unit and the real mirror of the object to be observed by the real mirror image forming optical system on the observer's line of sight It is possible to have images and eyes simultaneously. That is, the observer observes the display unit corresponding to the first display region on the back wall, and simultaneously displays the real mirror image of the observation object corresponding to the second display region formed in front of the display unit. You will be able to observe. For example, if only the display part is usually observed, and the real mirror image of the object to be observed is imaged in the space in front of the display part only when there is some trigger, nothing will happen Since an image appears in a space that should not exist, a display device that can obtain an image observation method that can more easily attract the attention of the observer can be realized at low cost without using a plurality of displays.

  Since the object to be observed displayed in the second display area is observed by the observer through the reflecting mirror or the real mirror image forming optical system, there is a loss at the time of reflection. The display brightness is preferably brighter than the display brightness of the first display area.

  In order to cause the observer to observe the real image formed in the space by the real mirror image forming optical system with impact, the size and position of the display of the second display area on the screen are changed with time. It is preferable to make it. This temporal change may be continuous or discontinuous (discrete). When the temporal change of the image is discontinuous, the amount of temporal change of the real image can be increased, so that the alerting function for the observer can be emphasized.

  In the present invention, the real mirror image forming optical system is capable of observing a real mirror image of the object to be imaged from a viewpoint from an oblique direction with respect to the base (symmetric plane). As a specific example, a real mirror image forming optical system comprising a two-surface corner reflector array can be cited. A two-sided corner reflector array is a planar assembly of a plurality of two-sided corner reflectors composed of two orthogonal mirror surfaces. One common plane perpendicular to all the mirror surfaces is covered. This is a plane of symmetry between the observed object and the real mirror image. This two-surface corner reflector array reflects the light emitted from the object to be observed twice by the two mirror surfaces of each two-surface corner reflector, and transmits the light through the symmetry plane. It has the effect of forming a real mirror image of the object to be observed at a plane symmetrical position of the object to be observed with respect to the plane.

  Here, considering the two-sided corner reflector array, in order to transmit the light beam through the element plane while appropriately bending each of the two-sided corner reflectors, the two-sided corner reflector is optically assumed to pass through the symmetry plane. It can be considered that the inner wall of a typical hole is used as a mirror surface. However, such a two-sided corner reflector is conceptual and does not necessarily reflect the shape determined by the physical boundary. For example, optical holes are connected without being independent of each other. Can be used.

  The structure of the two-surface corner reflector array is simply described by arranging a large number of mirror surfaces substantially perpendicular to the symmetry plane on the symmetry plane. The problem as a structure is how to support and fix the mirror surface to the symmetry plane. As a more specific method of forming a mirror surface, for example, a two-sided corner reflector array is provided with a base that partitions a predetermined space, and one plane passing through the base is defined as a symmetry plane. The corner reflector can be used as an optical hole assumed in a direction passing through the symmetry plane, and the inner wall of the hole formed in the base can be used as a mirror surface. The hole formed in the substrate only needs to be transparent so that light can pass through, for example, the inside may be filled with a vacuum or a transparent gas or liquid. Also, the shape of the hole may be any shape as long as the inner wall has a mirror surface not included in one or more coplanar surfaces to serve as a unit optical element, and the light reflected by the mirror surface can pass through the hole. It may be a complicated shape in which each hole is connected or a part thereof is missing. For example, an aspect in which individual mirror surfaces stand on the surface of the base can be understood as connecting holes formed in the base.

  Alternatively, the two-surface corner reflector may use a cylindrical body formed of a solid such as transparent glass or resin as an optical hole. In addition, when each cylindrical body is formed of solid, these cylindrical bodies may be brought into close contact with each other and serve as a support member for the element, and project from the surface of the base as having a base. You may take the aspect which did. The cylindrical body also has one or more mirror surfaces not included in the same plane for acting as a two-surface corner reflector on its inner wall, and the light reflected by the mirror surface can pass through the cylindrical body. As long as it can take any shape, it may be a cylindrical body, but it may be a complicated shape in which each cylindrical body is connected or partially missing.

  Here, as the optical hole, a shape in which all adjacent inner wall surfaces are orthogonal, such as a cube or a rectangular parallelepiped, can be considered. In this case, the distance between the two-surface corner reflectors can be minimized, and a high-density arrangement is possible. However, it is desirable to suppress reflection on surfaces other than the two-surface corner reflector that faces the object to be observed.

  When there are a plurality of mirror surfaces in the two-sided corner reflector, there is a possibility that there is multiple reflected transmitted light that causes reflection more than the expected number of times. As a countermeasure against this multiple reflection, when two mirror surfaces orthogonal to each other are formed on the inner wall of the optical hole, the surfaces other than these two mirror surfaces are made non-mirror surfaces so that light is not reflected, By providing an angle or providing a curved surface so as not to be vertical, it is possible to reduce or eliminate multiple reflected light that causes three or more reflections. In order to obtain a non-mirror surface, it is possible to employ a configuration in which the surface is covered with an antireflection coating or a thin film, or a configuration in which the surface roughness is roughened to cause irregular reflection. It should be noted that even a transparent and flat substrate does not hinder the function of the optical element, so that the substrate can be arbitrarily used as a support member / protective member.

  Furthermore, in order to increase the brightness of the actual mirror image, it is desirable to arrange a plurality of two-sided corner reflectors on the symmetry plane with as little spacing as possible. For example, it is effective to arrange them in a grid pattern. is there. Further, in this case, there is an advantage that manufacture is also facilitated. As a mirror surface in a two-sided corner reflector, a mirror that reflects a flat surface formed of a glossy substance such as a metal or a resin regardless of whether it is solid or liquid, or between transparent media having different refractive indexes. A material that reflects or totally reflects on a flat boundary surface can be used. Further, when the mirror surface is configured by total reflection, undesired multiple reflection by a plurality of mirror surfaces is likely to exceed the critical angle of total reflection, so that it can be expected to be naturally suppressed. Further, the mirror surface may be formed on a very small part of the inner wall of the optical hole as long as there is no functional problem, and may be constituted by a plurality of unit mirror surfaces arranged in parallel. In other words, the latter aspect means that one mirror surface may be divided into a plurality of unit mirror surfaces. In this case, the unit mirror surfaces do not necessarily have to be on the same plane as long as they are parallel to each other. Further, each unit mirror surface is allowed to be either in contact with or apart from each other.

  Furthermore, as another specific example applicable as a real mirror image forming optical system in the present invention, an optical system including a retroreflector array that retroreflects light rays and a half mirror having a half mirror surface that reflects and transmits light rays. It is a system. In this real mirror image forming optical system, the half mirror surface is a surface (symmetric surface) that is set to be exposed on the base with the upper surface of the dashboard, and is reflected or transmitted by the half mirror among the light rays emitted from the object to be observed. The thing which has arrange | positioned the retro-reflector array in the position which can retroreflect a light ray can be mentioned. The retro reflector array is disposed only in the space on the same side as the object to be observed with respect to the half mirror, and is provided at a position where the light reflected by the half mirror is retroreflected. Here, “retroreflection”, which is the action of the retroreflector, refers to a phenomenon in which the reflected light is reflected (reversely reflected) in the direction in which the incident light is incident. The incident light and the reflected light are parallel and opposite to each other. Become. A plurality of such retroreflectors arranged in an array is a retroreflector array. If the individual retroreflectors are sufficiently small, the paths of incident light and reflected light can be regarded as overlapping. In this retroreflector array, the retroreflectors do not have to be on a plane, may be on a curved surface, and do not have to be on the same plane, and each retroreflector is scattered three-dimensionally. It does not matter. The half mirror refers to a mirror having both a function of transmitting light and a function of reflecting light, and preferably has a transmittance and a reflectance of approximately 1: 1.

  As the retro reflector, one composed of three adjacent mirror surfaces (which can be called a “corner reflector” in a broad sense) or a cat's eye retro reflector can be used. The corner reflector includes a corner reflector composed of three mirror surfaces orthogonal to each other, two of the angles formed by the three adjacent mirror surfaces are 90 degrees, and the other angle is 90 / N degrees (N May be an acute angle retroreflector or the like in which the angles formed by the three mirror surfaces are 90 degrees, 60 degrees, and 45 degrees.

  In the case of a real mirror imaging optical system that uses such a retroreflector array and a half mirror, the light emitted from the object to be observed is reflected by the half mirror surface, and recursively antireflected by the retroreflector array. Since it returns to the direction and forms an image through the half mirror surface, the shape and the position of the retroreflector array are not limited as long as the reflected light from the half mirror is received. The observed real image can be observed from the direction opposite to the light beam that passes through the half mirror surface.

  When using a retro reflector array, it is necessary to pay attention to the positional relationship between the second display area and the retro reflector array. Specifically, it is necessary to prevent the retroreflector array from being arranged on the optical path where the light from the second display area reaches the reflecting mirror.

  Even when an electronic display is used, the object of the present invention can be achieved with a single electronic display, so that the cost is not increased.

It is a perspective front view which shows the state which looked at the display apparatus of one Embodiment of this invention from the front side. It is a schematic side view which shows typically the state which looked at the principal part of the display apparatus of the embodiment from the side. It is a schematic perspective view which shows typically the image formation style of the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is the schematic plan view and partial notch perspective view which show typically the example of a specific structure of the 2 surface corner reflector ray applied to the display apparatus of the embodiment. It is a schematic plan view which shows typically the imaging style by the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is a schematic side view which shows typically the imaging style by the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is a schematic plan view which shows typically the image formation style at the time of combining a reflective mirror with the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is a schematic side view which shows typically the image formation style at the time of combining a reflective mirror with the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is a schematic perspective view which shows typically the image formation style at the time of combining a reflective mirror with the 2 surface corner reflector array applied to the display apparatus of the embodiment. It is a schematic perspective view which shows typically the aspect of the retroreflection of the light ray by an example of the retroreflector array applied to the real mirror image formation optical system of the principal part of the display apparatus of other embodiments by this invention, and a retroreflector. . It is a schematic side view which shows typically the aspect of the retroreflection of the light ray by the other example of the retroreflector array applied to the real mirror image formation optical system which shows other embodiment of this invention, and a retroreflector. FIG. 4 is a schematic partial plan view of a retroreflector array applied to the real mirror image forming optical system and a schematic partial plan view schematically showing a mode of retroreflection of light rays by an example of the retroreflector. FIG. 6 is a schematic partial plan view of another retroreflector array applied to the real mirror image forming optical system, and a schematic partial plan view schematically showing a mode of retroreflection of light rays according to another example of the retroreflector.

  Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows the periphery of a dashboard of an automobile vehicle including a display device 1 to which the present invention is applied. FIG. 2 is a schematic sectional view showing an embodiment of the display device 1 to which the present invention is applied. This display device 1 is one in which the present invention is applied to an instrument panel provided in a driver's cab of a transport device such as an automobile and a portion around it. Specifically, the display device 1 arranges the back wall 2 in a portion farthest from the viewpoint V of the driver who is an observer, and surrounds the four sides of the space in front of the driver when viewed from the driver side. Are provided with a bottom wall 3, left and right side walls 4, and an upper wall 5, and a first display region 21 of a kind of instrument panel (instruments) is provided at the position of the back wall 2. The first display area 21 is displayed on the liquid crystal display 20. The liquid crystal display 20 has a transmissive display panel surface that continues to a region below the bottom wall 3, and a portion below the bottom wall 3 serves as a second display region 22 that is an “image P” of the object to be observed. Is displayed. A backlight BL is disposed on the rear surface of the display panel of the liquid crystal display, and the second backlight portion BL2 corresponding to the second display region is in contrast to the first backlight portion BL1 corresponding to the first display region. The light is emitted at about 4 times the brightness. In the present embodiment, a light emitting diode is used as the light source of the backlight, and the second backlight portion BL2 corresponding to the second display area has the first display area in order to change the light emission luminance for each area. The light emitting diodes are arranged at a mounting density about four times that of the corresponding first backlight portion BL1. A backlight partition plate BL3 is provided at the boundary between both display areas, and the brightness of each area is divided. In addition, it cannot be overemphasized that not only a speedometer like the example of illustration but various instruments can be displayed on the 1st display area 21 provided in the back wall 2. FIG.

  In this embodiment, a dihedral corner reflector array 6 is provided as a real mirror image forming optical system on the bottom wall 3 functioning as a wall portion in the present invention, and further, inside the bottom wall 3 (that is, a space on the lower surface side). A reflecting mirror 8 is arranged. The light emitted from the second display area 22 of the liquid crystal display is reflected by the reflecting mirror 8, and then forms an aerial image P as a real mirror image on the front side of the back wall 2 through the two-surface corner reflector array 6. In the illustrated example, when the vehicle speed exceeds a certain value, the second display area 22 of the liquid crystal display uses the characters “observe the speed!” As the object to be observed on the front side of the back wall 2. In addition, in the space above the bottom wall 3, the characters “Caution for speed!” Emerge as a real mirror image P. The reflecting mirror 8 is set at an appropriate angle to guide light from the object to be observed to the second display area 22 of the liquid crystal display to the two-surface corner reflector array 6.

  In order to describe the above relationship in more detail, first, the configuration and operation of the single-sided corner reflector array will be described, and then the operation when the reflecting mirror 8 is added will be described.

  As shown schematically in FIGS. 3 and 4, the single-sided corner reflector array 6 is a collection of a large number of two-sided corner reflectors 61 composed of two mutually orthogonal mirror surfaces 61 a and 61 b. A plane substantially perpendicular to each of the two mirror surfaces 61a and 61b constituting the surface corner reflector 61 is defined as a symmetry plane 6S, and a real mirror image P of the image 72 as an object to be observed is formed at the plane symmetry position. An aerial image is observed by a driver who is an observer. In the present embodiment, the two-surface corner reflector 61 is very small (μm order) compared to the overall size (cm order) of the two-surface corner reflector array 6, and therefore the two-surface corner reflector 61 of FIG. The entire set is represented in gray, the direction of the inner angle at which the mirror surface opens is represented by a V shape, and the two-surface corner reflector 61 is exaggerated. FIG. 4 shows a schematic plan view of the two-surface corner reflector array 6 in FIG. 4A and a partial perspective view in FIG. 4B. However, in FIG. 4, the two-surface corner reflector 61 and the mirror surfaces 61 a and 61 b are greatly exaggerated as compared with the entire two-surface corner reflector array 6.

  The double-sided corner reflector array 6 is formed with a number of physical and optical holes penetrating the thickness perpendicular to the flat base surface so that the light beam can be bent and transmitted, for example. Then, in order to use the inner wall surface of each hole as the two-surface corner reflector 61, it is possible to employ one in which mirror surfaces 61a and 61b are respectively formed on two orthogonal inner wall surfaces of the hole. Accordingly, as shown in FIG. 4, a physical / optical hole (for example, a square-shaped light beam having a substantially rectangular shape (for example, a square shape) in a plan view is transmitted through a thin flat plate-shaped substrate so that the substrate is at least translucent. If a plurality of adjacent inner walls that are orthogonal to each other are subjected to a smooth mirror surface treatment to form mirror surfaces 61a and 61b, the two mirror surfaces 61a and 61b are reflected surfaces. The two-surface corner reflector 61 can be obtained. Furthermore, by coloring the upper surface of the base including the upper ends of the mirror surfaces 61a and 61b to the same color as the bottom wall 3, the sense of unity with the bottom wall 3 can be increased. It should be noted that it is preferable to suppress the multiple reflected light by making the surface of the inner wall surface of the hole that does not constitute the two-sided corner reflector 61 into a surface that is not mirror-reflected and cannot reflect light, or is angled. . Further, in order to improve the integration with the bottom wall 3 described above, it is preferable that this surface (the portion not constituting the two-surface corner reflector 61) is also colored in the same color as the bottom wall 3. In addition, each of the two-surface corner reflectors 61 is preferably formed on a regular lattice point so that the inner angles formed by the mirror surfaces 61a and 61b are all in the same direction on the base. Therefore, in each two-surface corner reflector, it is preferable that the intersecting line of two orthogonal mirror surfaces CL is orthogonal to the symmetry plane 6S. Hereinafter, the direction of the inner angle of the mirror surfaces 61a and 61b may be referred to as the direction (direction) of the two-surface corner reflector 61.

  In forming the mirror surfaces 61a and 61b, for example, a metal mold is first prepared, and the inner wall surface on which the mirror surfaces 61a and 61b are to be formed is subjected to nano-scale cutting processing or a pressing method using the mold to the nano-scale. It is preferable that the mirror surface is formed by processing by the applied nanoimprint method or electroforming method, and that the surface roughness is 10 nm or less so that the surface is uniformly mirrored in the visible light spectrum region. In addition, when the base is formed of a metal such as aluminum or nickel by an electroforming method, the mirror surfaces 61a and 61b naturally become mirror surfaces if the surface roughness of the mold is sufficiently small. However, using the nanoimprint method When the substrate is made of resin or the like, it is necessary to perform mirror coating by sputtering or the like in order to create the mirror surfaces 61a and 61b. Moreover, the transmittance | permeability can be improved by setting the separation | spacing dimension of adjacent 2 surface corner reflectors 6 as small as possible. However, the configuration of the two-surface corner reflector array 6 is not limited to that described above, and a large number of two-surface corner reflectors 61 are formed by two orthogonal mirror surfaces 61a and 61b, and each of the two-surface corner reflectors 61 is an optical hole. As long as it transmits light, an appropriate configuration and manufacturing method can be adopted.

  In the double-sided corner reflector array 6, each double-sided corner reflector 61 reflects light entering the hole from the back side by one mirror surface 61a (or 61b), and further reflects the reflected light to the other mirror surface 61b (or 61a) has a function of reflecting the light and allowing it to pass to the front surface side, and the light entrance path and the light emission path are symmetrical with respect to the symmetry plane 6S. That is, the symmetry plane 6S (assuming a plane that passes through the center in the height direction of each mirror surface and is orthogonal to each mirror surface) of the two-surface corner reflector array 6 is a real image of the object 72 to be observed inside the bottom wall 3. This is a symmetry plane that forms a mirror image (real mirror image) at a plane symmetry position in the space above the bottom wall 3.

  Here, an image formation mode by the two-surface corner reflector array 6 will be briefly described along with a path of light emitted from the point light source o as an object to be observed. As shown in a schematic plan view in FIG. 5 and a schematic side view in FIG. 6, light emitted from a point light source o (indicated by a one-dot chain line arrow. When the light passes through the two-surface corner reflector array 6, it is reflected by one of the mirror surfaces 61a (or 61b) constituting the two-surface corner reflector 61 and further the other mirror surface 61b (or 61a). After passing through the symmetry plane 6S, it passes through the plane of symmetry of the point light source o with respect to the plane of symmetry 6S of the two-plane corner reflector array 6. In FIG. 5, the incident light and the reflected light are shown to be parallel, but this is because the dihedral corner reflector 61 is greatly exaggerated with respect to the point light source o in FIG. 5. Actually, each of the two-sided corner reflectors 61 is extremely small, and therefore, when the two-sided corner reflector array 6 is viewed from above as shown in FIG. That is, in the end, the transmitted light gathers at a plane-symmetrical position with respect to the plane of symmetry 6S of the point light source o, and forms an image as a real mirror image at the position p in FIGS.

  Next, the operation when the reflecting mirror 8 is added will be described with reference to FIGS. 7 and 8 corresponding to FIGS. FIG. 5 illustrates the path of light that first strikes each of the two mirror surfaces (61a, 61b) of the two-surface corner reflector 61, that is, two paths. In FIG. 7, either one is used to avoid complication. Only the first light hitting one of the mirrors is drawn. The basic idea is that a mirror image is formed at a position p by turning back the light path by a reflecting mirror 8 formed by a plane mirror disposed on the path of light emitted from the light source o and directed toward the two-sided corner reflector 61. Is imaged. That is, the position of the light source o in FIGS. 5 and 6 and the position of the light source o in FIGS. 7 and 8 are objects when the reflector 8 is viewed from the direction of the dihedral corner reflector array 6 (the light source in FIGS. 7 and 8). and the virtual image o ′ (corresponding to the light source o in FIGS. 5 and 6).

  When the reflection mirror 8 according to the present embodiment is added, the relationship between the two-surface corner reflector array 6, the reflection mirror 8, and the second display region 22 of the liquid crystal display is depicted as corresponding to FIG. become that way. From the above description, it can be seen that in this embodiment as well, the character “speed attention!” Can emerge as a real mirror image P in the space in front of the back wall 2 and above the bottom wall 3.

  In this way, since the two-surface corner reflector array 6 is incorporated in the bottom wall 3, as shown in FIG. 1, the front side of the first display area 21 provided on the back wall 2 (driving as an observer). The real mirror image P can be projected in the air (as viewed by the person). That is, since a caution display like this example appears in the air that should originally have nothing, it is easy to call attention to the observer. In addition, since the real mirror image P appears on the front side of the first display area 21 of the instruments, attention is not required even if the observer (driver) does not remove the line of sight of the first display area 21 from other places. Since the display can be seen, it can be said that it is also useful for safe driving.

  Here, if the real mirror image P to be viewed by the observer is changed with time, it is extremely useful for facilitating the viewer's attention. In this embodiment, since the observation plane image is created in the second display area 22 using the liquid crystal display, it is easy to add such a change. For example, the display position and size of the observation image can be changed. It is also possible to change the real mirror image P by changing it. Changes in the temporal size and position of these observation images may be continuous or discontinuous.

  As described above, the display device 1 of the present embodiment is provided with the first display area 21 for displaying instruments on the liquid crystal display on the back wall 2 as an application of the present invention to the instrument panel of an automobile. A two-sided corner reflector array 6 is provided on the bottom wall 3 protruding to the driver side from the back wall, and a reflecting mirror 8 is disposed inside the bottom wall 3 (that is, the space on the lower surface side). The light emitted from the second display area 22 is reflected by the reflecting mirror 8, and then the aerial image P is raised on the near side of the back wall 2 through the two-surface corner reflector array 6, so that the driver can be alerted. Is. Furthermore, in the present embodiment, since the first display area 21 and the second display area 22 are formed on the same liquid crystal display, an additional display device for realizing the aerial image P is not necessary. Achieved at low cost. In addition, this invention is not limited to embodiment mentioned above. In the above-mentioned example, the description was made on the case where the text “speed attention!” Was observed as an aerial image. However, since the object to be observed was created on the liquid crystal display, various other documents such as An image (either a still image or a moving image) can be displayed and the real mirror image P can be imaged in the air to be shown to the driver. The object to be observed is not limited to a two-dimensional image. A three-dimensional stereoscopic image can also be used, and the real mirror image P observed accordingly can also be a three-dimensional image. However, when the two-surface corner reflector array 6 is used, the depth of the object to be observed and the real mirror image is inverted. Therefore, by setting the object to be observed in a state where the depth is inverted in advance, the correct depth can be obtained. The real mirror image can be shown to the driver.

  10 and 11 are schematic views showing another embodiment of a display device to which the present invention is applied. An overview of the display device 1 ′ as seen from the front is the same as FIG. 1. This display device 1 'differs from the display device 1 of the above-described embodiment only in the real mirror image forming optical system. Therefore, the same configuration as the display device 1 will be described using the same name and reference numeral.

  The real mirror image forming optical system 9 applied in this embodiment is a combination of a half mirror 91 and a retroreflector array 92. Then, a half mirror 91 is provided on the bottom wall 3 that functions as a wall portion, and a reflecting mirror 8 is disposed inside the bottom wall 3 (that is, the space on the lower surface side) to display a second object of the liquid crystal display. The light emitted from the display area 22 is reflected by the reflecting mirror 8 and guided to the half mirror 91. The liquid crystal display 20 displays the first display area 21 and the second display area 22 on the same screen as in the first embodiment.

  A retro-reflector array 92 is disposed below the second display region 22 and has a function of retroreflecting light from the half mirror 91. Accordingly, the light emitted from the second display area 22 of the liquid crystal display for displaying the object to be observed is reflected by the reflecting mirror 8, then reflected by the half mirror 91, and directed to the retro reflector array 92, and then the retro reflector. The light is retroreflected by the array 92 and heads toward the half mirror 91 again. This time, the real mirror image P is formed through the half mirror 91. In this way, the same display as in FIG. 1 can be provided to the observer.

  As the half mirror 91, for example, a thin reflective film coated on one surface of a transparent thin plate such as a transparent resin or glass can be used. By applying anti-reflection treatment (AR, coating) to the opposite surface of the transparent thin plate, it is possible to prevent the observed real mirror image P from being doubled. An optical film such as a view control film or a viewing angle adjustment film as a line-of-sight control means that transmits light in a specific direction and blocks light in another specific direction or diffuses only light in a specific direction on the upper surface. (Specifically, this optical film is used to prevent light directly transmitted through the half mirror 91 from reaching any position other than the viewpoint V.) The observation image reflected on the reflecting mirror 8 from other than the viewpoint V can be prevented from being directly observable through the reflector V. 92 By that transmits only light in a direction through the half mirror 91 after retroreflection, and can be observed only real mirror image P from a particular view point V.

  On the other hand, any kind of retroreflector array 92 can be applied as long as it reflects the incident light strictly, and a retroreflective film or a retroreflective coating on the surface of the material is also conceivable. Moreover, the shape may be a curved surface or a flat surface. For example, a retroreflector array 92 shown in FIG. 12 (a) with an enlarged part of the front view is a corner cube array that is a set of corner cubes that use one corner of a cubic body corner. Each of the retro reflectors 92A forms a regular triangle when the mirror surfaces 92Aa, 92Ab, and 92Ac that form three isosceles right-angled isosceles triangles are gathered at one point and viewed from the front. The mirror surfaces 92Aa, 92Ab, and 92Ac are orthogonal to each other to form a corner cube. In addition, a retroreflector array 92 shown in an enlarged part of the front view in FIG. 13A is also a corner cube array that is a set of corner cubes that use one corner of the cube body corner. The individual retro reflectors 92B form three regular mirror surfaces 92Ba, 92Bb, 92Bc, which are formed into a single hexagonal shape when they are gathered at one point. 92Bb and 92Bc are orthogonal to each other. The retroreflector array 92 is different in shape from the retroreflector array 92 of FIG. 12A, and the principle of retroreflection is the same. 12B and 13B, the retroreflector array 92 shown in FIGS. 12A and 13A will be described as an example. Of the mirror surfaces of the retroreflectors 92A and 92B, FIG. The light incident on one (for example, 92Aa, 92Ba) is sequentially reflected on the other mirror surfaces (92Ab, 92Bb) and further on the other mirror surfaces (92Ac, 92Bc), so that the light has entered the retroreflectors 92A, 92B. Reflects in the original direction. The paths of the incident light and the outgoing light with respect to the retroreflector array 92 are not strictly overlapping but are parallel to each other. However, when the retroreflectors 92A and 92B are sufficiently smaller than the retroreflector array 92, the incident light and the outgoing light. May be considered as overlapping. The difference between these two types of corner cube arrays is that the mirror surface is isosceles triangle is relatively easy to create, but the reflectivity is slightly lower, and the mirror surface is square is slightly easier to create than the isosceles triangle. While difficult, it has a high reflectivity.

  In addition to the corner cube array described above, a retroreflector array 92 that can retroreflect light rays with three mirror surfaces (“corner reflector” in a broad sense) can be employed. Although not shown, for example, as a unit retroreflective element, two mirror surfaces of three mirror surfaces are orthogonal to each other, and another mirror surface is 90 / N degrees with respect to the other two mirror surfaces (where N is an integer) And acute angle retroreflectors having angles of 90 degrees, 60 degrees, and 45 degrees formed by the adjacent mirror surfaces of the three mirror surfaces are suitable as the retroreflective element 3 applied to the present embodiment. In addition, a cat's eye retro reflector or the like can also be used as a unit retroreflective element. These retro-reflector arrays may be planar or bent or curved. Also, the arrangement position of the retroreflector array can be set appropriately as long as the light emitted from the image 72 and reflected by the half mirror 91 can be retroreflected.

  In the display device 1 ′ of this embodiment to which the real mirror image forming optical system 9 including the half mirror 91 and the retroreflector array 92 is applied, the display device 1 ′ to which the two-surface corner reflector array 6 is applied is the same. From the viewpoint of the observer (driver) viewing from the oblique direction with respect to the half mirror surface 91, the real mirror image P (letter “speed attention!”) Appears to float in front of the back wall 2. . In the display device 1 as well, the actual mirror image P can be changed by changing the display position and size of the observation image.

  Furthermore, since the first display area 21 and the second display area 22 are formed on the same liquid crystal display in the present embodiment, an additional display device for realizing the aerial image P is unnecessary. Achieved at low cost.

  In addition, the specific configuration of each part constituting the display device can be changed as appropriate without departing from the spirit of the present invention, and as an application example of the display device, in addition to the instrument panel of an automobile, The present invention can be appropriately configured as a display device that causes an aerial image to emerge in front of the display unit for various devices provided with the display unit.

  The present invention can be used as an information display device for a vehicle such as a vehicle.

1, 1 '... Display device 2 ... Back wall 3 ... Wall (bottom wall)
4 ... Side wall 5 ... Upper wall 6 ... Two-sided corner reflector array (real mirror image forming optical system)
6S ... Symmetrical surface 8 ... Reflector 20 ... Liquid crystal display 21 ... First display region 22 ... Second display region 91 ... Half mirror 91S ... Half mirror surface (symmetric surface)
92 ... Retro-reflector arrays 92A, 92B ... Retro-reflectors 92Aa, 92Ab, 92Ac, 92Ba, 92Bb, 92bc ... Mirror surface BL ... Backlight BL1 ... First backlight portion BL2 ... Second backlight portion BL3 ... Backlight partition plate P ... Aerial video (real mirror video)

Claims (9)

A display unit that includes a first display area that is provided on the back wall and is directly viewed by the observer, toward the viewer side;
A second display area included in the display unit and including display information;
A wall portion that is arranged closer to the viewer than the back wall and partitions the viewer-side space of the second display region and the viewer-side space of the first display region;
A reflecting mirror disposed in a space on the viewer side of the second display area so as to face the second display area, and a translucent base provided on the wall and including a symmetry plane And a real image of the second display area is formed at a plane symmetrical position with respect to the symmetry plane of the virtual image of the second display area by the reflector in the space on the viewer side of the first display area. And a real mirror image forming optical system for imaging. The real mirror image forming optical system includes a two-surface corner reflector array including a plurality of two-surface corner reflectors arranged with a gap in the symmetry plane of the base;
Each of the two-surface corner reflectors consists of two orthogonal mirror surfaces, and the line of intersection of the mirror surfaces is orthogonal to the symmetry plane;
In the second display area, a part of the light beam emitted from the second display area enters the intersection line of the mirror surface through the reflecting mirror and passes between the two-surface corner reflectors. The display device according to claim 1, wherein the display device is arranged so as to reach a space on the viewer side of one display region. The real mirror image forming optical system includes a half mirror formed on the base and arranged as the symmetry plane;
A plurality of retro-reflectors arranged in a position for retroreflecting the light beam reflected by the half mirror among the light beams emitted from the second display region in a space on the viewer side of the second display region; The display device according to claim 1.   The display device according to claim 1, wherein the first display area and the second display area are formed on a screen of a single electronic display.   The display device according to claim 4, wherein the display brightness of the second display area is brighter than the display brightness of the first display area.   The display device according to claim 4, wherein a size of the display of the second display area on the screen changes with time.   The display device according to claim 4, wherein a position of the display of the second display area on the screen changes with time.   The display device according to claim 6, wherein the temporal change is approximately continuous.   The display device according to claim 4, wherein the temporal change is discontinuous.

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