Image display device

In an image display device, a floating image display unit focuses light left from an image screen on an image plane in a space to display a floating image. The space is located on one side of an image transfer panel opposite to the other side thereof facing a display unit. A direct-view image display unit includes a display unit having an image screen on a plane orthogonal or oblique to the image plane from a periphery of the image plane and outputs, in a first direction far from the image transfer panel and in a second direction close thereto, two-dimensional images, respectively. A reflection and pass unit reflects part of the light left from the display unit in the second direction toward a direction far from the image transfer panel, and allows part of the light left from the display unit to pass therethrough.

This application is the U.S. national phase of International Application No. PCT/JP2007/057192, filed 30 Mar. 2007, which designated the U.S., the entire contents of which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to image display devices for pseudo-stereoscopically displaying two-dimensional images.

BACKGROUND ART

An image display device, in which an image transfer panel (for example, a microlens array consisting of a plurality of lenses) is placed in front of a two-dimensional image at a predetermined space therefrom, for displaying a pseudo stereoscopic image (floating image) of the two-dimensional image onto a space in front of the image transfer panel has been known (for example, see a first patent document and a second patent document). The image display device is adapted to focus the two-dimensional image by the image transfer panel while floating the two-dimensional image, thus displaying the two-dimensional image as if to display a three-dimensional image.

These image display devices include an image display device equipped with two screens for two-dimensional images; this image display device causes images displayed on one of the screens to be recognized as pseudo-stereoscopic images of the two-dimensional images, and causes images displayed on the other of the screens to be recognized as direct-view images (for example, see a third patent document).First patent document: Japanese Patent Laid-Open No. 2001-255493Second patent document: Japanese Patent Laid-Open No. 2003-098479Third patent document: Japanese Patent Laid-Open No. 2005-234240

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The image display device equipped with the two screens for two-dimensional images is able to display combined images of direct-view images and floating images, making it possible to increase stereoscopic visual effects.

However, in an image display that interlocks a direct-view image and a floating image, an increase in stereoscopic visual effects provides users more realistic images.

The present invention has been made in view of the aforementioned circumstances, and has an example of a purpose of providing an image display device capable of strengthening the interlock between a direct-view image and a floating image, thus more increasing stereoscopic visual effects.

Means for Solving the Problems

In order to achieve such a purpose provided above, an image display device according to a first aspect of the invention includes a first display unit having a first image screen for displaying a two-dimensional image; and an image transfer panel located far from the first image screen, including: a floating image display means that focuses light left from the first image screen on an imaging plane in a space to thereby display a floating image, the space being located on one side of the image transfer panel opposite to the other side thereof facing the first display unit; and a direct-view image display means including: a second display unit having a second image screen on a plane orthogonal or oblique to the imaging plane from a periphery of the imaging plane and adapted to output, in a first direction far from the image transfer panel and in a second direction close thereto, two-dimensional images, respectively; and a reflection and pass unit located close to the image transfer panel and adapted to: reflect part of light left from the second display unit in the second direction toward a direction far from the image transfer panel; and allow part of the light left from the first display unit to pass therethrough.

DESCRIPTION OF CHARACTERS

BEST MODES FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2are schematically structural views of an image display device100according to an embodiment of the present invention.FIG. 1is an outline perspective view of the image display device100, andFIG. 2is a cross sectional view of the image display device100as viewed from its lateral direction (A-A direction ofFIG. 1).

The image display device100is a pseudo stereoscopic-image display device for displaying, on a preset plane in a space, two-dimensional images that are visibly recognizable by a viewer H as pseudo stereoscopic images. The image display device100is provided with a floating image display unit1for displaying floating images (two-dimensional images to be displayed on a preset plane in a space), and a direct-view image display unit2for displaying direct-view images that are directly viewed by the viewer H.

The floating image display unit1is made up of a display unit10, and an image transfer panel20located to be spaced from the display unit10. The display unit10is equipped with an image screen11for displaying two-dimensional images, and with a display driver12for drive and control of the display unit10. The display unit10displays, on the image screen11, an image according to drive signals of the display driver.

Specifically, as the display unit10, a color liquid crystal display (LCD) can be used, which is provided with a flat screen11and a display driver12consisting of an illuminating backlighting unit and a color liquid crystal drive circuit. Note that another device except for the LCD, such as an EL (Electro-Luminescence) display, a plasma display, CRT (Cathode Ray Tube), or the like, can be used.

The image transfer panel20includes, for example, a microlens array25with a panel screen arranged in substantially parallel to the image screen11of the display unit10. The microlens array25, as illustrated inFIG. 3, is configured such that two lens array halves21a,21bare arranged in parallel to each other. Each of the lens array halves21a,21bis designed such that a plurality of micro convex lenses23are two-dimensionally arranged to be adjacent to each other on either surface of a transparent substrate22made from high translucent glass or resin; the micro convex lenses23have the same radius of curvature.

An optical axis of each of the micro convex lenses23aformed on one surface is adjusted such that the adjusted optical axis is aligned with the optical axis of a corresponding micro convex lens23bformed at an opposing position on the other surface. Specifically, individual pairs of the micro convex lenses23a,23badjusted to have the same optical axis are two-dimensionally arranged such that their respective optical axes are parallel to each other.

The microlens array25is placed in parallel to the image screen11of the display unit10at a position far therefrom by a predetermined distance (a working distance of the microlens array25). The microlens array25is adapted to focus light, corresponding to an image and left from the image screen11of the display unit10, on an imaging plane30on the side opposite to the image screen11and far therefrom at the predetermined distance (working distance of the microlens array25). This displays the image displayed on the image screen11on the imaging plane30as a two-dimensional plane in a space.

The formed image is a two-dimensional image, but is displayed to float in the space when the image has depth or the background image on the display is black with its contrast being enhanced. For this reason, the viewer H looks the formed image as if it is floated. Note that the imaging plane30is a virtually set image in the space and not a real object, and one plane defined in the space according to the working distance of the microlens array25.

The microlens array25, as illustrated inFIG. 4, is adjusted to be arranged such that:

light corresponding to an image P1and left from the image screen11of the display unit10is incident from the lens array half21a, flipped thereinside at one time, flipped again, and thereafter, outputted from the lens array half25b.

This allows the microlens array25to display the two-dimensional image P1displayed on the image screen11of the display unit10as an erected floating image P2on the imaging plane30.

More specifically, in the light forming the two-dimensional image P1to be displayed on an image screen11a, light of an image in a region corresponding to each of the micro convex lenses23of the microlens array25is captured by each of the micro convex lenses23, flipped in each of the micro convex lenses23, flipped again, and outputted so that the floating image P2is displayed as a set of erected images formed by the respective micro convex lenses23.

Note that the microlens array25is not limited to the structure of a pair of two lens array halves21a,21b, and can be configured by a single lens array, or by a plurality of lens arrays equal to or greater than three lens arrays. Of course, when a floating image is formed by odd-numbered, such as one or three, lens array halves21, referring to (a) and (b) ofFIG. 5, light incident to the micro lens array25is flipped at one time therein, and flipped again. For this reason, it is possible to display an erected floating image. As described above, various configurations of the microlens array25can be made. These configurations allow the working distance for forming light to have a constant effective range without limiting the single working distance.

Note that, in the embodiment, the image transfer panel20is the microlens array25, but not limited thereto, and can be any member for forming erected images, desirably erected equal-magnification images, such as other forms of lenses, or mirrors or prisms; these mirrors or prisms form erected equal-magnification images. For example, a gradient index lens array, a GRIN lens array, a rod lens array, or the like can be a microlens array, and a roof mirror array, a corner mirror array, a dove prism or the like can be a micromirror array. One Fresnel lens having a required active area, which forms a reverted image, can be used in place of arrays.

The direct-view image display unit2is made up of a display unit40, and a half mirror50for reflecting light left from the display unit40. As well as the display unit10, the display unit40is equipped with an image screen41for displaying two-dimensional images, and with a display driver42for drive and control of the display unit40. The display unit40displays, on the image screen41, an image according to drive signals of the display driver.

Specifically, as the display unit40, a color liquid crystal display (LCD) can be used, which is provided with a flat screen41and a display driver42consisting of an illuminating backlighting unit and a color liquid crystal drive circuit. Note that another device except for the LCD, such as an EL (Electro-Luminescence) display, a plasma display, CRT (Cathode Ray Tube), or the like, can be used.

The image screen41of the display unit40is so placed at a region in front of the image transfer panel20(the side of the imaging plane30) under the floating image P2in substantially orthogonal to the imaging plane30as to allow the viewer H to directly view an image displayed on the image screen41. Note that, in the embodiment, the image screen41is arranged under the floating image, but the arrangement of the image screen41is not limited thereto. The image screen41can be placed at any one of an upper side, a lower side, a left side, and a right side of the floating image, or can be placed simultaneously at any plurality of the upper side, the lower side, the left side, and the right side of the floating image.

Moreover, the display unit40, as illustrated inFIG. 2, is an LCD from which light can exit in different directions, and is adapted such that light is left from the image screen41in both first direction d1(a direction far from the image transfer panel20: +X direction) and second direction d2(a direction close to the image transfer panel20: −X direction). Note that light left in the first direction d1will be referred to as “first light”, and an image outputted and displayed based on the first light will be referred to as “first image”. Similarly, light left in the second direction d2will be referred to as “second light”, and an image outputted and displayed based on the second light will be referred to as “second image”. Information to be displayed by the first image and that to be displayed by the second image can be different from each other, or can be associated with each other.

Let us simply describe a principle of a liquid crystal display from which light can exit in different directions with reference toFIG. 6. Note that the display unit40according to the embodiment adopts a parallax barrier system illustrated inFIG. 6, but another system, such as a time division system, can be adopted.

The display unit40, as illustrated inFIG. 6, includes: a liquid crystal display unit42athat alternately arranges and displays a first image P3and a second image P4pixel by pixel in a front-back direction (X direction) of the viewer H, a backlight42bthat irradiates illumination light from the back of the liquid crystal display unit42a, and a parallax barrier unit42cthat controls the direction of light left from the liquid crystal display unit42a.

The parallax barrier unit42cis formed such that light transmissive areas and light blocking areas are formed in stripes in the front-back direction. For this reason, the first image P1and the second image P2left from the liquid crystal image unit42awith their directions of light controlled are displayed and outputted in the first direction d1and the second direction d2, respectively. Note that angles of the first and second directions d1and d2can be changed depending on the width of the light blocking areas.

The half mirror50is arranged vertically adjacent to the front side (imaging plane30side) of the image transfer panel20, and a half mirror surface51of the half mirror50and the image screen41of the image display unit40are substantially vertically arranged. These configurations allow the half mirror50to:

reflect some of light left from the image screen41of the image unit40in the second direction d2toward a third direction d3; and

allow some of light displayed as a floating image and left from the image screen11of the display unit10to pass therethrough. For this reason, the viewer H can view the first light left in the first direction d1as a direct-view image, view the second light reflected by the half mirror50in the third direction d3, and, at the same time, view, as a floating image, the light left from the image screen11and passing through the half mirror50.

In this case, it seems to the viewer H as if the second image based on the second light is outputted and displayed on an image display plane41a(a virtual plane41a) located symmetrically with respect to the image screen41and the half mirror51(it appears that the second light left from S1is left from S1a). For this reason, the direct-view image has depth in the front-back direction.

Specifically, even if the image screen41is actually placed in front of the image transfer panel20, it is possible to achieve a same advantage achieved when the image screen41is placed at the back of the image transfer panel20(the display unit10side), in other words, to double the image screen41toward the back side, thus improving the expressive power of the direct-view image.

Note that the half mirror50needs to reflect some of light incident thereto and allow the remaining light to pass therethrough, and therefore, each of the reflection factor and the transmission factor need not be 50%.

An image controller3is adapted to generate image data to be displayed on the display units10and40, and carry out image-display control to thereby interlock the image data to be displayed on the display unit10and the image data to be displayed on the display unit40. For example, change in the display image to be displayed on the display unit40with change in the display image to be displayed on the display unit10or change in the display image to be displayed on the display unit10with change in the display image to be displayed on the display unit40interlock a floating image and a direct-view image, thus enhancing stereoscopic visual effects. Note that, for the generation of image data, an image storage unit in which predetermined images have been stored can be provided.

FIG. 7schematically illustrates an example of images that the image display device100displays. The images illustrated inFIG. 7are car navigation images. A traffic control sign P2aas a floating image, maps P3aand P4aas direct-view images, and a shadow P3bof the traffic control sign P2aare displayed. Thus, the floating image and the direct-view images are images associated with each other, and interlocking the floating image and the direct-view images increases stereoscopic visual effects.

Note that, in the images illustrated inFIG. 7, the first image P3and the second image P4as the direct-view images are different from each other, and the combination of the first image P3and the second image P4expresses one completed direct-view image. Specifically, the map information P3aof the first image and the map information P4aof the second image are smoothly spanned in the front-back direction so as to show one map information, thus providing the map information an illusion of depth. As described above, the image display device100widens an area for recognizing the direct-view images toward the back. This increases the interlock with the floating image, making it possible to further increases stereoscopic visual effects.

FIG. 8schematically illustrates another example of images that the image display device100displays. The images illustrated inFIG. 8are also car navigation images. A motor vehicle P2aas a floating image, maps P3aand P4aas direct-view images, and a shadow P3bof the motor vehicle P2aare displayed. InFIG. 8, the shadow P3bof the motor vehicle as the direct-view image is gradually reduced in size with gradual reduction in size of the motor vehicle P2aas the floating image so that the shadow P3bmoves to the back side on the map (the shadow of the motor vehicle moves from the first image P3bto the second image P4b). For this reason, it is possible for the viewer H to feel that the motor vehicle P2amoves from the near side to the far side.

FIG. 9schematically illustrates a further example of images that the image display device100displays. The images illustrated inFIG. 9are also car navigation images. A traffic control sign P2aas a floating image, maps P3aand P4aas direct-view images, and a shadow P3cof the motor vehicle P2aare displayed. InFIG. 9, when the traffic control sign P2amoves on the map from the far side to the near side so as to reach a predetermined position, the traffic control sign is changed from the direct-view image to the floating image so that it is displayed to be popped up.

As described above, the image display device100according to the embodiment provides a direct-view image an illusion of depth, changes the direct-view image according to the change in a floating image (seeFIG. 8), and changes the floating image according to the change in the direct-view image (seeFIG. 9). For this reason, it is possible to provide the viewer H stereoscopic visual effects that interlock the floating image and the direct-view image.

Note that the aforementioned image display device100locates the image screen41of the display unit40in parallel to the ground, but can locate the image screen41of the display unit40to be inclined to the ground.FIGS. 10 and 12are schematic structural views of image display devices in which their image screens41are inclined to the ground.

FIG. 10is an outline side view of an image display device100A when the image screen41of the image display unit40is inclined to the ground, and the half mirror surface51of the half mirror50and the image screen41of the image display unit40are substantially formed vertically. Specifically, the image screen11of the display unit10and the panel surface of the image transfer panel20are arranged vertically to the ground, and there is an obtuse angle required between the panel surface of the image transfer panel20and the image screen41of the image display unit40.

Referring toFIG. 10, the half mirror50is arranged closely at the front side of the image transfer panel20, and the image transfer panel20and the half mirror50are arranged in non-parallel to each other. In this case, because the image screen41and the image display plane41a(a virtual plane41a) are formed on a same plane, the viewer H views a direct-view image displayed on one inclined plane.

FIG. 11illustrates an example of images that the image display device100A displays. The contents of the images are car navigation images as well asFIG. 7, and, in the case of the image display device100A, the direct-view image can be seen on the plane that rises from the near side to the far side. For this reason, the map as the direct-view image can be more easily seen.

FIG. 12is an outline side view of an image display device100B when the image screen41of the image display unit40is inclined to the ground, and the half mirror surface51of the half mirror50is designed to be adjacent to the panel surface of the image transfer panel20. Specifically, the image screen11of the display unit10and the panel surface of the image transfer panel20are arranged vertically to the ground, and there is an obtuse angle formed between the panel surface of the image transfer panel20and the image screen41of the image display unit40. An obtuse angle is also formed between the image screen41of the image display40and the half mirror surface51of the half mirror50.

In this case, the image screen41and the image display plane41a(a virtual plane41a) are non-coplanar with each other, and two planes bent to form a crest are formed. For this reason, the viewer H views a direct-view image displayed on the two planes bent in crest shape.

FIG. 13illustrates an example of images that the image display device100B displays. The contents of the images are car navigation images as well asFIG. 8, and, in the case of the image display device100B, because a crest terrain as the direct-view image can be expressed, it is possible to provide the viewer H a feeling of going over a mountain. In this case, for example, the shade P3bof the vehicle as the direct-view image can be controlled to move toward the far side on the map, and the vehicle P2aas the floating image can be controlled to move vertically along the inclination of the image screen41or the image display plane41a(vertical plane41a).

Note that other variations can be applied to image display devices with the image screen41being inclined to the ground. For example, an acute angle can be formed between the image screen41of the image display unit40and the half mirror surface51of the half mirror50. In this case, a trough terrain can be expressed contrary to an image displayed by the image display device100B. In addition, the inclination of the image screen41is not always fixed to a constant angle, but the angle of the inclination of the image screen41can be moved. For example, for car navigation images, the angle of the inclination of the image screen41can be moved along an actual terrain.

Moreover, a sensor unit, such as a touch panel, can be mounted on the image screen41of the image display device100according to the embodiment.FIG. 14is a functional structural view of such an image display device100C. The image display device100C, in addition to the structure of the image display device100, is provided with a sensor driver43that drives the sensor unit and receives a detection signal detected by the sensor unit. Specifically, the operations of the viewer H are detected by the sensor unit on the image display screen41, and the floating image and the direct-view image are changed according to the detected signal.

FIG. 15illustrates an example of images that the image display device100C displays. As the images illustrated in (a) ofFIG. 15, a traffic control sign P2aas a floating image, a map P1aas a near-side direct-view image, audio information P4aas a far-side direct-view image, such as the name of a piece of music being reproduced, the name of an artist, an image of a sleeve, and the like, are displayed. Specifically, in the direct-view images illustrated in (a) ofFIG. 15, different images that are not associated with each other are displayed at the front side and back side, respectively.

In such a situation, for example, in order to change the piece of music being reproduced to another piece of music, when the viewer H pushes down a switch button44on the image screen41, it is detected by the sensor unit. This results in that, as illustrated in (b) ofFIG. 15, the near-side direct-view image and the far-side direct-view image are replaced with each other so that the image display device100C displays the audio information P3bas the near-side direct-view image, the map P4bas the far-side direct-view image, and the image P2bof the sleeve as the floating image. Furthermore, a piece of music to be changed can be selected from an album list displayed in the near-side audio information P3b. As described above, the switch between the near-side and far-side direct-view images, selection of an album, or the like can be functioned as operations of the viewer H from the sensor unit.

Note that, in the image display device100C, the sensor unit is mounted on the image screen41, but not limited thereto. A position detection sensor for detecting a viewer H's touch of the floating image (a position coordinate in the imaging plane30) or a position detection sensor for detecting a viewing position of the viewer H (a distance from the imaging plane30) can be mounted on a preset position of a housing (not shown). When such a sensor unit is mounted, it is possible to change the floating image and the direct-view image according to the operating position and the viewing position of the viewer H. For this reason, it is possible to bring the image display device to have interactive abilities.

As described above, the image display unit100according to the embodiment of the present invention includes:

the display unit10provided with the image screen11that displays two-dimensional images;

the image transfer panel20located to be spaced from the display unit10;

floating image display means1that focuses light left from the image screen11on the imaging plane30in a space to thereby display a floating image, the space being located across the image transfer panel20from the display unit10; and

direct-view image display means2including:a display unit40provided with the image screen41on a plane orthogonal or oblique to the imaging plane30from a periphery of the imaging plane30and adapted to output, in the first direction d1far from the image transfer panel20and in the second direction d2close thereto, two-dimensional images, respectively; anda reflection and pass unit50located close to the image transfer panel20and adapted to:reflect some of the light left from the image display unit40in the second direction d2toward the direction d3far from the image transfer panel20; andallow some of light left from the display unit10to pass therethrough.

Thus, the interlock between the direct-view image and the floating image is increased, making it possible to enhance stereoscopic visual effects.

The embodiment of the present invention has been described, but the present invention is not limited to the embodiment. The embodiment of the present invention can be subjected to various modifications and deformations within the scope of the subject matter of the present invention. The embodiment with the deformations or modifications can be within the scope of the present invention.