JP5799535B2 - System for generating aerial 3D image and method for generating aerial 3D image - Google Patents

Description

This application was filed on April 3, 2009 and is a US patent application entitled “RETRO-REFLECTIVE LIGHT DIFFUSING DISPLAY SYSTEMS” and assigned to the assignee of this application. “Retroreflective light diffusing display system” assigned to the assignee of the present application, filed on October 28, 2009, claiming its benefits in a partially pending application with No. 12 / 418,137 The benefit is claimed in a partially pending application of US Patent Application No. 12 / 607,840 entitled “RETRO-REFLECTIVE LIGHT DIFFUSING DISPLAY SYSTEMS”). Each of the above applications is incorporated herein by reference.
The present invention relates generally to display, and more specifically to autostereoscopic three-dimensional (3D) display.

  Three-dimensional movies and television are becoming increasingly popular. With advances in technology such as high definition (HD) television, consumers want more and better quality features. According to the 2008 2008 3D Television Report published by Insight Media in May 2008, 3D may soon become an add-on feature to high-definition television. Many display manufacturers have developed their own 3D display technology to satisfy these market requirements (see, for example, Patent Document 1).

  In the current 3D market, the traditional standard two-view solid is still the dominant practice. For example, head-mounted displays are widely used in the military training and research community, and eyeglass-based projection displays play an important role in 3D cinemas with Mechdyne Corporation's CAVE® and PowerWall systems. However, the requirement to wear a helmet or glasses limits the use of 3D technology. As another solution, autostereoscopic display technology is gaining more and more attention. Autostereoscopic display uses a special light element to create a separate display window in the user space that allows the user to view 3D images without glasses. The designated display window forms a display space that is significantly larger than the human eye so that the user can move his head freely as long as the eye is in the display space.

US Pat. No. 7,425,070

The three-dimensional methods currently used to implement the display window include displays based on parallel shielding and displays based on lenses. However, these autostereoscopic display techniques have considerable limitations.
For example, displays based on parallel shielding are subject to some limitations. First, since the parallel shielding display uses a light shielding to realize the display window, only a small amount of light emitted from each pixel passes through the shielding window. Second, the crosstalk between displays can be substantial. Crosstalk refers to the overlap of display areas that results when one eye sees the image intended for the other eye. If the crosstalk is substantial, the brain cannot perceive the stereo effect or perceive it correctly. Third, the use of small apertures in displays based on parallel shielding can cause diffraction. This problem becomes more serious as the display resolution increases. As the display resolution increases, the size of the shielding aperture must be reduced, causing a more serious diffraction effect.

  Fourth, the display based on parallel shielding has limited resolution. For a display with n displays, the individual resolution is basically 1 / n of the original display resolution. Since the display must divide the original display resolution, the display resolution based on parallel shielding is limited by the original resolution of the display, which is further limited by diffraction along with the capabilities of the display manufacturer.

  Fifth, since each display sees only one row of individual pixels connected to one occluded window, there are many dark pixels in each display, creating a “pile fence effect” in a monocular image. Finally, displays based on parallel shielding usually have the problem that the number of display windows is limited. In order to generate more display windows, the slit slit width must be wider while the dark slit window remains unchanged. Naturally, it is impossible to increase the number of display windows infinitely without collecting artifacts such as reduced brightness and pile fence effect.

  Although the display based on lenses shows some improvement over the display based on parallel shielding, the use of lenticular sheets also has important drawbacks. Lens-based displays provide higher resolution than shielding slits, but it is more difficult and expensive to make high quality lenticular sheets than to make simple black and white shielding. In fact, the display quality is directly related to the quality of the lenticular sheet used for display. Furthermore, lens-based displays suffer from problems that plague displays based on parallel shielding, such as crosstalk between display windows, dark line problems, limited resolution, and a limited number of display windows.

  Therefore, there is a need for systems and methods that provide better displays, particularly better displays that can be used for autostereoscopic display.

The system for generating an aerial three-dimensional image of the present invention includes:
A multi-display window three-dimensional display system for generating a plurality of display windows;
An optical condensing element, which is located farther from the focal length of the optical condensing element and away from the plurality of display windows of the multi-display window three-dimensional display system, the multi-display window three-dimensional display system An optical condensing element that receives light from and condenses the light to form a plurality of projection display windows,
The plurality of projection display windows are selected from the plurality of projection display windows by viewing a first unique perspective image with a first eye in a first projection display window selected by the user from the plurality of projection display windows. The second projection display window is positioned so that the aerial three-dimensional image can be seen by viewing the second unique perspective image with a second eye.

  In the system for generating an aerial three-dimensional image of the present invention, the optical condensing element is a lens or a concave mirror.

  The system for generating an aerial three-dimensional image according to the present invention further includes a beam splitter positioned between the three-dimensional display system of the multi-display window and the concave mirror.

Further, in the system for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window has a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction And a diffusion layer forming a display window.

Moreover, in the system for generating an aerial three-dimensional image of the present invention, the screen further includes a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer,
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. It is what makes it do.

Further, in the system for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window has a plurality of projectors,
Each of the plurality of projectors has a unique position, and is configured to project a perspective display image on the screen to form a display window corresponding to the projection image.

In the system for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer, receiving a diffuse reflection image from the light diffuser layer and condensing the diffuse reflection image to form a display window; and
A light diffuser layer located at a focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, diffusing the reflected image, and a diffusely reflected image Forming said light diffuser layer;
And a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image onto the light diffuser layer to form a reflected image.

Moreover, in the system for generating an aerial three-dimensional image of the present invention, the screen further includes a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer,
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. It is what makes it do.

On the other hand, the system for generating an aerial three-dimensional image of the present invention is:
A multi-display window three-dimensional display system having a plurality of projectors for projecting a plurality of projection images and generating a plurality of display windows;
An optical condensing element,
The optical condensing element is located farther than a focal length of the optical condensing element and is separated from a plurality of display windows of the multi-display window three-dimensional display system, and from the multi-display window three-dimensional display system. Receiving light and condensing the light to form a plurality of composite images, each of the plurality of composite images being formed by a plurality of image portions from a plurality of projection images, each composite image having a unique viewpoint area That can be seen from
The aerial three-dimensional image can be viewed by an observer viewing the first perspective image with the first eye in the first viewpoint area and viewing the second perspective image with the second eye in the second viewpoint area. It is possible to do it.

  In the system for generating an aerial three-dimensional image according to the present invention, the plurality of projectors are located on a main plane of the optical condensing element.

In the system for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window further includes a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction And a diffusion layer forming a display window.

  In the system for generating an aerial three-dimensional image of the present invention, the optical condensing element is located between the plurality of display windows and the screen.

Further, in the system for generating an aerial three-dimensional image of the present invention, the screen further includes a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer,
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. It is what makes it do.

In the system for generating an aerial three-dimensional image of the present invention,
The multi-display window three-dimensional display system further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer, receiving a diffuse reflection image from the light diffuser layer and condensing the diffuse reflection image to form a display window; and
A light diffuser layer located at a focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, diffusing the reflected image, and a diffusely reflected image Forming said light diffuser layer;
And a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image onto the light diffuser layer to form a reflected image.

In the system for generating an aerial three-dimensional image of the present invention,
The screen further comprises a transparent medium located between the two-dimensional retroreflective surface and the diffuser layer;
The transparent medium has the image out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by a diffuser layer. It is what makes it do.

Here, the method for generating an aerial three-dimensional image of the present invention is as follows.
Generating a plurality of display windows using a three-dimensional display system of multiple display windows;
From the three-dimensional display system of the multi-display window using the optical condensing element located farther from the focal length of the optical condensing element and away from the plurality of display windows of the three-dimensional display system of the multi-display window Receiving light and condensing the light to form a plurality of projection display windows,
The plurality of projection display windows are selected from the plurality of projection display windows by viewing the first unique perspective image with the first eye in the first projection display window selected by the user from the plurality of projection display windows. Further, the second projection display window is positioned so that the aerial three-dimensional image can be seen by viewing the second unique perspective image with the second eye.

  In the method for generating an aerial three-dimensional image according to the present invention, the optical condensing element is a lens or a concave mirror.

In the method for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window further includes a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction And a diffusion layer forming a display window.

Further, in the method for generating an aerial three-dimensional image of the present invention, the screen further comprises a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer,
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. It is what makes it do.

In the method for generating an aerial 3D image according to the present invention, the 3D display system of the multi-display window further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer; receiving a diffuse reflection image from the light diffuser layer; condensing the diffuse reflection image to form a display window; and
The light diffuser layer located at the focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, and diffusing the reflected image to form a diffusely reflected image When,
And a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image to the light diffuser layer to form the reflected image.

On the other hand, the method for generating an aerial three-dimensional image of the present invention includes:
Projecting a plurality of projected images using a multi-display window three-dimensional display system that generates a plurality of display windows having a plurality of projectors;
Using the optical concentrating element located near the focal length of the optical condensing element and away from the plurality of display windows of the three-dimensional display system of the multi-display window;
The step of using the optical condensing element receives light from the three-dimensional display system of the multi-display window, condenses the light to form a plurality of composite images, each composite image from a plurality of projection images Each of the composite images can be viewed from a unique viewpoint area,
The aerial three-dimensional image can be viewed by an observer viewing the first perspective image with the first eye in the first viewpoint area and viewing the second perspective image with the second eye in the second viewpoint area. It is possible to do it.

  In the method for generating an aerial three-dimensional image according to the present invention, the plurality of projectors are located on a main plane of an optical condensing element.

In the method for generating an aerial three-dimensional image of the present invention, the three-dimensional display system of the multi-display window further includes a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction And a diffusion layer forming a display window.

  In the method for generating an aerial three-dimensional image according to the present invention, the optical condensing element is located between the plurality of display windows and the screen.

On the other hand, the system for generating an aerial three-dimensional image of the present invention is:
A multi-display window three-dimensional display system for generating a plurality of display windows;
An optical condensing element, which is equal to the focal length of the optical condensing element and is spaced apart from the plurality of display windows of the multi-display window three-dimensional display system, the multi-display window three-dimensional display system An optical condensing element that receives light from and condenses the light to form the plurality of projection display windows at infinity or virtually at infinity,
The plurality of projection display windows are positioned so that a user can view the three-dimensional aerial image by viewing the first mosaic image with a first eye and the second mosaic image with a second eye. The first and second mosaic images are formed from at least a part of at least some of the plurality of projection display windows.

FIG. 6 is a diagram of the operation of a light diffusing screen according to various embodiments of the invention. It is a figure of an effect | action of the retroreflection type screen by various embodiment of this invention. FIG. 6 is a diagram illustrating the operation of a retroreflective vertical light diffusing screen according to various embodiments of the present invention. 1 is a diagram of a display system having a retroreflective vertical light diffusing screen according to various embodiments of the present invention. FIG. 1 is a diagram of a multiple projector display system having retroreflective vertical light diffusing screens according to various embodiments of the invention. FIG. FIG. 5 is a diagram of another multiple projector display system having retroreflective vertical light diffusing screens according to various embodiments of the invention. FIG. 6 is a diagram of another embodiment of a display system having a retroreflective vertical light diffusing screen according to various embodiments of the present invention. FIG. 6 is a diagram of yet another embodiment of a display system having a retroreflective vertical light diffusing screen according to various embodiments of the present invention. FIG. 6 is a diagram of another embodiment of a retroreflective light diffusing screen according to various embodiments of the invention. FIG. 10 is a diagram of the retroreflective light diffusing screen of FIG. 9 according to various embodiments of the invention. It is a figure which shows the example of a lenticular reflective screen. It is a figure which shows another embodiment of the retroreflection type | mold light-diffusion screen which has a lens layer by various embodiment of this invention. FIG. 6 depicts a light distribution in a display window from an embodiment of a retroreflective light diffusing screen according to various embodiments of the present invention. FIG. 6 depicts a cross section of two adjacent display windows from an embodiment of a retroreflective light diffusing screen according to various embodiments of the present invention. It is a figure which shows another embodiment of the retroreflection-type light-diffusion screen by various embodiment of this invention. It is a figure which shows embodiment of the aerial three-dimensional image display system by various embodiment of this invention. FIG. 3 is a diagram illustrating ray tracing of an embodiment of an aerial three-dimensional image display system according to various embodiments of the present invention. It is a figure which shows the position and size of a virtual screen and a projection display window in the aerial three-dimensional image display system by various embodiment of this invention. 1 is a diagram illustrating an aerial three-dimensional image display system according to various embodiments of the present invention. It is a figure which shows another embodiment of the aerial three-dimensional image display system by various embodiment of this invention. It is a figure which shows another embodiment of the aerial three-dimensional image display system by various embodiment of this invention. It is a figure which shows another embodiment of the aerial three-dimensional image display system by various embodiment of this invention. It is a figure which shows another embodiment of the aerial three-dimensional image display system by various embodiment of this invention. It is a figure which shows the effect | action of the transmission projection image display which an observer views an image from a different position. 1 is a diagram illustrating an embodiment of an aerial three-dimensional image display system forming a transmission projection / light field display system according to various embodiments of the present invention. FIG. It is a figure which shows the trace of the light ray of one projector in embodiment of the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. It is a figure which shows the effect | action of the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. It is a figure which shows embodiment of the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. It is a figure which shows different embodiment of arrangement | positioning of the projector and optical element in the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. It is a figure which shows another embodiment of the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. It is a figure which shows another embodiment of the light irradiation field type aerial three-dimensional display system by various embodiment of this invention. 1 is a diagram illustrating a multi-projector display system according to various embodiments of the invention. FIG. It is a figure drawing the block diagram of the example of an arithmetic system by embodiment of this invention.

  Aspects of the invention relate to generating a novel display screen using light diffusion and retroreflectivity. In the embodiment, an autostereoscopic display can be generated by generating a plurality of display windows using a retroreflective light diffusing screen. In an embodiment, each display window draws a perspective image display, while one eye sees one perspective image display from one display window and the other eye sees another perspective image display from another display window. You can see 3D images.

  In an embodiment, the display screen comprises a screen having a two-dimensional retroreflective surface and a diffusing surface. The diffusion surface is composed of a large diffusion angle in the first direction and a small diffusion angle in the second direction. For the display screen, the first direction is preferably the vertical direction, and the second direction is preferably the horizontal direction. The diffusing surface is further configured to receive the image reflected from the two-dimensional retroreflecting surface and diffuse the image to form a display window corresponding to the image.

  In an embodiment, the display screen system comprises a retroreflector diffuser screen and at least one additional layer. In an embodiment, the additional layer may be a transparent layer between the two-dimensional retroreflector and the light shaping diffuser. In an embodiment, the additional layer may be a lens layer located in front of the light shaping diffuser. In yet another embodiment, the retroreflector diffuser screen comprises a lens layer, a light shaping diffuser, a transparent media layer, and a two-dimensional retroreflector.

  The display screen system can also include a plurality of projectors. Each projector has a unique position, and is configured to project a unique perspective display image onto the screen, thereby forming a unique display window corresponding to the projected image. Accordingly, the display system forms a plurality of display windows corresponding to the plurality of images projected by the plurality of projectors. The user sees the first perspective image with one eye in the first display window selected from the plurality of display windows, and the second perspective image in the second display window selected from the plurality of display windows. By this, a three-dimensional image can be viewed.

  In an embodiment, the display screen system is located in an optical path between at least one of the plurality of projectors and the screen, guides the projected image to the screen, directs the projected image reflected from the screen to a position, and is spaced from at least one of the plurality of projectors There is also a beam splitter that forms a distant display window. Such a configuration eliminates the projector becoming an obstacle to the display window.

  In an embodiment, the display system also includes a second retro-reflective light diffusing screen that is placed in an optically mirrored position relative to the first screen to increase image brightness in the display window.

  In an embodiment, the display system includes at least one of a plurality of projectors and a polarization-responsive beam splitter that is positioned in the optical path between the screens and guides a projected image to the screen, and a quarter-wave plate positioned in the optical path between the screen and the beam splitter. .

  In the embodiment, the display system includes an arithmetic device that is connected to a plurality of projectors in communication and adjusts the projection of an image. The computing device can include one or more data stores that store the images to be projected. It is noted that the projected image can be a still image, a video image, or both.

  Embodiments of the present invention further include a method of configuring an autostereoscopic display system in accordance with the teachings presented herein. For example, in an embodiment, an autostereoscopic display system can be formed by positioning a retroreflective light diffusing screen to receive images from multiple projectors. Each projector has a unique position, and is configured to project a unique perspective display image onto the screen, thereby forming a unique display window corresponding to the projected image. A plurality of display windows corresponding to the plurality of images projected by the plurality of projectors are formed. The multiple display windows are three-dimensional by allowing the user to see the first perspective image with one eye in the first display window selected from the multiple display windows and the second perspective image with the other eye in the second display window. Positioned so you can see the image.

  Aspects of the invention further include systems and methods for generating floating three-dimensional displays. In an embodiment, the optical concentrating element is projected from a display window in a display system based on a multi-display window at a distance equal to or greater than the focal length of the optical condensing element, allowing a user to see a floating 3D image. Forming a display window. In another embodiment, the optical focusing element is located at a distance less than the focal length of the optical focusing element from the display window in a multi-display window based display system. Form. In the aerial three-dimensional display embodiment, one of the retroreflective light diffusing screen embodiments presented herein is used in a display system based on multiple display windows.

  While some of the features and advantages of the invention have been generally described above, additional features, advantages, and embodiments are presented herein or can be made by one of ordinary skill in the art in light of the drawings, specification, and claims of this application. It will be clear if there is any. Accordingly, it will be understood that the scope of the invention is not limited by the specific embodiments disclosed in this summary section.

  In the following description, for purposes of explanation, specific details are set forth in order to provide an understanding of the invention. However, it will be apparent to one skilled in the art that the invention may be practiced without these details. Further, those skilled in the art will appreciate that the embodiments of the invention described below can be implemented in a variety of forms. Accordingly, the examples described below are illustrative of specific embodiments of the invention and are intended to avoid obscuring the invention.

  The components, or modules, shown in the block diagrams are illustrative of exemplary embodiments of the invention and are intended to avoid obscuring the invention. Also, throughout this discussion, a component may be described as a separate functional unit that may have subunits, but those skilled in the art can divide various components, or portions thereof, into separate components, or a single unit Understand that they can be integrated together, including integration into systems or components.

  Furthermore, the connections between the components in the drawings are not intended to be limited to direct connections. Conversely, the data between these components can be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections can be used. It is further noted that the terms “coupled” or “communicatively coupled” are understood to include direct connections, indirect connections through one or more intermediate devices, and wireless connections.

  In the specification, references to “one embodiment”, “preferred embodiment”, “an embodiment” or “an embodiment” refer to a particular feature, structure, characteristic, or function described in connection with that embodiment. It is included in at least one embodiment, meaning that it can be included in more than one embodiment. The appearances of the phrase “in one embodiment”, “in an embodiment”, or “in an embodiment” in various places in the specification do not necessarily refer to the same embodiment. Further, it will be understood that the advocacy of “image” or “multiple images” as used herein means still images, video images, or both.

A. Overview Most 3D display methods rely on binocular parallax cues to generate three-dimensional (3D) images. Binocular parallax refers to viewing a pair of stereoscopic images of the same 3D object (ie, two different viewpoints). A head-mounted display is one such display device where the user views two separate stereoscopic images through two separate light paths. Stereo glass, shutter glass, and polarizing glass are widely used to separate stereo images displayed on a single screen or printed on paper.

  The autostereoscopic display technique also relies on a key to the depth of parallax. However, instead of separating the stereoscopic display with the glass in front of the user's eyes, most of the naked-eye stereoscopic display attempts to generate a display window in the user space by controlling the optical path in the display space. Only one monocular image can be observed in each display window. The display window further forms a display area. Since the size of the display area is much larger than the size of the human eye, the user can move his head freely within the display area. Most existing autostereoscopic display systems are based on a parallel shielding technique or a lenticular technique.

1. Display based on parallel shielding The basic design using parallel shielding is to place strips to shield the light emitted from the display. Usually a black and white mask grid is placed in front of the display. Each small white grid serves as a pinhole that maps the pixel to the display space and allows the user to see the pixel from a specific viewing angle (ie, creates a display window), while the black grid is the viewing angle To block adjacent pixels. As a result, the user sees one set of pixels in the display in the left display window and the user sees the other set in the display in the right display window. The left display window and the right display window together form one display area. More than one display area can be formed. In addition, multiple display windows can be created within a single display area by increasing the display resolution and associating more pixels with each shielding slit.

  As mentioned above, displays based on parallel shielding have several drawbacks. These disadvantages are: reduced brightness, crosstalk between displays, diffraction effects due to small windows, resolution limitations, pile fence effects in monocular images, artifacts of image reversal when exceeding the display area, and a limited number of Includes display window.

  First, because the display based on parallel shielding uses a light shielding strategy, only a small amount of light emitted from each pixel passes through the shielding window. Accordingly, the brightness of the viewed image is reduced. Attempts to reduce the brightness problem include placing a shielding mask behind the display. The light is modulated by the shield before reaching the display pixel.

  Second, the crosstalk between displays can be significant. Crosstalk refers to overlapping display areas, which can result in one eye seeing the image intended for the other eye. If the crosstalk is substantial, the brain cannot perceive the stereo effect or perceive it correctly. Attempts to minimize crosstalk artifacts involve selecting a shielding pitch for the shielding mask or placing the shielding behind the display.

  Third, the use of small apertures in displays based on parallel shielding can cause diffraction. This problem becomes more serious as the display resolution increases. As the display resolution increases, the size of the shield hole must be reduced, causing a more severe diffraction effect. Therefore, the size of the shielding hole is limited by the diffraction limit.

  Fourth, displays based on parallel shielding are usually plagued with limited resolution. For a display having n displays, the resolution of each display is basically 1 / n of the original display resolution. Since the display must divide the original display resolution, the display resolution based on parallel shielding is limited by the original resolution of the display, which is also limited by the resolution that the display manufacturer can achieve with diffraction.

  Fifth, there are many dark pixel lines in each display because each display sees only one of the n pixel columns associated with one shielding window. For two viewpoints, the dark line is 1 pixel wide and intertwined with these bright pixels. Dark pixel lines form a “pile fence effect” in monocular images. Attempts to reduce pile fence artifacts involve making the shielding lines at an angle with respect to the displayed pixel columns.

  Sixth, these displays can suffer from image reversal artifacts. Image reversal artifacts are due to incorrect alignment between the user's eyes and the display window. In a two-viewpoint display system, the user sees an inverted set of stereoscopic images when the user's left eye is in the right display window and the user's right eye is in the left display window. For multi-display display systems, such inversion artifacts occur when the user exceeds the display area.

  Finally, displays based on parallel shielding are usually plagued by a limited number of display windows. In order to generate more display windows, it is necessary to increase the width of the dark slit without changing the slit window. It is impossible to increase the display window without increasing artifacts such as reduced brightness and pile fence effect.

2. Lens-based display As mentioned above, one of the drawbacks of display based on parallel shielding is the lack of brightness due to the narrow vertical slits of the shielding. One solution to this problem is to use a lens to improve light collection. One form of lens used is a lenticular sheet, which includes a set of cylindrical lenses arranged side by side. To use a lenticular sheet for displaying 3D images, align the sheet perpendicular to the 2D display. Similar to a parallel occlusion display, when aligning two sets of pixels (eg, left eye pixel and right eye pixel), two display windows can be created to form a single display area. Multiple display areas (with L and R display windows) can also be created. When aligning multiple pixels with each lens, multiple display windows can be created in one display area. Since the lens in the lenticular sheet is cylindrical, only horizontal parallax is produced. In addition to improving the light collecting ability compared to a display based on parallel shielding, the lenticular sheet can provide higher resolution than the shielding slit.

  While a lens-based display has a higher potential in brightness and resolution than a parallel-shielded display, a lens-based display presents its own disadvantages. First, the display quality depends on having a high quality lenticular sheet. However, it is more difficult and costly to produce a high quality lenticular sheet, especially compared to a shielding mask. In addition, aligning the lenticular sheet with the display requires considerable effort. In addition, lens-based displays suffer from problems that plague display based on parallel shielding, such as crosstalk between display windows, pile fence problems, limited resolution, image inversion, and a limited number of display windows.

3. Display based on light diffusion The third type of multi-view 3D display uses light shaping diffuser (LSD) technology. Examples of devices that use light shaping diffusers are a light field display called HoloVizo ^TM developed by Holografika in Budapest, Hungary, and a 3D light field display developed by the Institute of Creative Technology at the University of Southern California. Is included. A light shaping diffuser is a one-dimensional light diffuser used as a backlight for optical communication devices and LCD displays. When illuminated by a projector, the light shaping diffuser has a small diffusion in the horizontal direction and a large diffusion in the vertical direction.

Holografika uses one-dimensional diffusion properties in its HoloVizo ^™ display. The display uses several projectors that illuminate the LSD screen. In the horizontal cross section, assuming that the screen only diffuses light in the vertical direction, the viewer can see only one very thin slit image from each projector. In order to generate a single viewpoint, it is necessary to mosaic the thin slits from these different projectors. Therefore, the display needs to operate in cooperation with a large number of projectors. For the HoloVizo ^TM display system, as many as 50 projectors are used in the prototype. Assuming a horizontal diffusion angle of 1 degree, approximately 60 projectors are required to produce a multi-view display with a field of view of 60 degrees.

Developed by the Creative Technology Laboratory at the University of Southern California, the light field display decodes high-speed video projectors, rotating mirrors covered with holographic diffusers, and specially displayed digital visual interface (DVI) video signals It consists of a field programmable gate array circuit. A high-speed video projector and a rotating mirror covered by a holographic diffuser produce a 360 degree field of view. The light field display developed by the Creative Technology Laboratory at the University of Southern California has similar characteristics to the HoloVizo ^™ display.

  While these displays do not share all of the drawbacks of parallel shielding and lens based displays, these methods have some unique problems. For example, there may be extra costs for crosstalk problems, difficult system calibration, and display.

First, there can be a crosstalk problem with the HoloVizo ^™ display. Crosstalk artifacts can be introduced by a light diffuser. The ideal diffuser should be a perfect low pass filter (ie a perfect rectangle). However, the actual material has a Gaussian diffusion pattern. As a result, there can be crosstalk between two adjacent narrow slits, which may cause the image to be significantly blurred or generate a zigzag image.

Second, both systems require very specific and complex components and require complex system calibration. For example, because images on a HoloVizo ^™ display are mosaicked from multiple projector image fragments, these projectors must be properly aligned and calibrated. The light field display developed by the Creative Technology Laboratory at the University of Southern California also requires special equipment and special settings.

Finally, an extra cost is required for image display. In the case of a HoloVizo ^™ display, at least part of the display cost is due to its special image mosaic conditions. The image displayed on the projector is not a normal 3D movie perspective image or an image displayed by standard OpenGL software. Therefore, extra steps must be taken to generate the correct image for each projector. Also, in the case of a light field display developed by the Creative Technology Laboratory at the University of Southern California, the system requires a specially displayed DVI video signal.

B. Embodiments of Autostereoscopic Display Embodiments of the present invention include using light shaping diffusion with retroreflection. First, such a system can use the full resolution of the projector and can display bright images. In the system of the present invention, each viewpoint image can be generated by only one projector, and when the user views an image at a specified display position, it is not necessary to mosaic display from a plurality of projectors. Further, the image does not require a special display video signal. As a result, the special post-display processing described above is not necessary. Compared to parallel shielding and lens based displays, the system does not suffer from similar limited resolution, and is usually much brighter and can theoretically create a larger number of display windows. Further advantages will be apparent to those skilled in the art.

C. Retroreflective light diffusing screen (RRVLD)
In an embodiment, the autostereoscopic display of the present invention comprises two layers. The first layer comprises a one-dimensional (1D) light diffusing material having a small diffusion angle in one direction and a large diffusion angle in the other direction. FIG. 1 depicts an example of a light diffusing material according to an embodiment of the invention.

  As shown in FIG. 1, the incident light beam 105 passing through the light diffusing material 110 is diffused at a narrow angle 115 in the horizontal direction but at a wide angle 120 in the vertical direction. In the case of 3D display application, it is preferable that the diffusion is small in the horizontal direction, while it is preferable that the diffusion is large in the vertical direction. Therefore, this type of diffusion screen can be called a vertical light diffusion screen.

  The second layer of the screen is a retroreflective material that reflects light rays in the direction of incidence. FIG. 2 depicts an example of a retroreflective material and its interaction with light rays. Incident light 210 or 220 strikes the retroreflective material 205 and is reflected. The reflected ray is reflected at the same or nearly the same angle as the incident ray. Thus, the incident ray 210 has a retroreflective line 215 that is reflected along the direction of the incident line 210. The incident light beam 220 also has a retroreflective line 225 that is reflected along the direction of the incident line 220.

FIG. 3 depicts a retroreflective vertical diffuse screen 300 according to various embodiments of the invention. The screen 305 illustrated in FIG. 3 is formed of a light diffusing material 310 combined with a retroreflective material 315. In an embodiment, a one-dimensional light diffusing material such as Light Shaping Diffusers (LSD (R)) manufactured by Luminit LLC of Torrance, California can be used. The light shaping diffusing material may have a diffusion angle of 60 × 1, but those skilled in the art will appreciate that other diffusion angles can be used. In an embodiment of the 3D display system, the light shaping diffusing material is oriented with a diffusion angle of 60 in the vertical direction and a diffusion angle of 1 in the horizontal direction. In embodiments, manufactured by 3M Corporation ^TM Scotchlite ^TM Reflective Material manufactured by 3M Corporation of St. Paul, Minnesota, or Reflexite Americas of New Britain, Connecticut, such as the company's P66 and AC1000. Retroreflective materials such as photoelectric control products having a metallized back can be used.

  As depicted in FIG. 3, light 320 directed to the retroreflective vertical light diffusing screen 305 passes through the diffusing material and is retroreflected along its incident direction 325 (or substantially along the incident direction). The The retroreflected light is then diffused by the light diffusing material 310. The light diffusing material 310 is configured to diffuse a small amount of retroreflected light in the horizontal direction 330 and a large amount in the vertical direction 335. Therefore, when the obtained diffused light passes through the diffusing material, it becomes a fan shape.

D. Embodiment of display system General Display System Embodiments FIG. 4 depicts a display system 400 according to various embodiments of the invention. FIG. 4 shows a retroreflective vertical light diffusing screen 405 and a projector 410. The retroreflective light diffusing screen 405 is used as a display screen. The light beam 415 emitted from the projector is retroreflected by the projector 410 to create a display window 425 that overlaps the projector. The screen 405 is configured such that the reflected light is diffused with a large diffusion angle in the vertical direction and with a small diffusion angle in the horizontal direction. Due to the vertical diffusion effect, the display window is a vertical slit that is centered on the aperture of the projection lens. The width of the slit 425 is a function of the horizontal diffusion angle of the screen, the distance from the projector, and the aperture size of the projection lens. The following equation defines the calculation of the width of the vertical slit.

  It is noted that the advantage of having a large vertical diffusion angle is that the display window is extended. Without an extended display window, the display window matches the lens of the projector and a person cannot see the reflected image. By extending the display window in the vertical direction, the user can view an image in the display window above or below the projector 410.

  FIG. 5 depicts a 3D display system 500 according to various embodiments of the invention. FIG. 5 shows a retroreflective vertical light diffusing screen 505 and a set of projectors 510A-F. Although FIG. 5 depicts six projectors, it is noted that more or fewer projectors can be used. The retroreflective vertical light diffusing screen 505 is used as a display screen in a manner similar to that described in connection with FIG. That is, the light beam 515 emitted from the projector 510x is reflected by the projector 510x to create a display window 525x that overlaps the projector. For example, light from projector 510A is reflected and diffused by screen 505 to form display window 525A. This result is the same for each projector in the display system 500, and each projector 510A-F generates a corresponding display window 525A-F. Thus, by adding a projector, a similar display window is further created.

  The display system depicted in FIG. 5 generated six separate display windows. Each display window displays an image from the corresponding projector. By displaying a set of images captured from multiple viewpoints of the screen through a projector, the user can view in 3D through these display slits or windows. For example, when a user views one image in one display window with one eye and another perspective image in another display window with the other eye, the user perceives a 3D image. In an embodiment, the width of the slit may be small enough so that the user does not perceive a monocular image by viewing the same image in the same display window with both eyes.

  Those skilled in the art will appreciate that the type of display system depicted in FIG. 5 has several advantages. First, the image is bright. One-dimensional light diffusion allows the user to see images that are much brighter than images using other steric methods, such as displays based on normal diffusing screens or parallel shielding.

  Second, the display screen can be configured in different shapes. Depending on the retroreflective properties of the material, the screen shape can take any form, including a regular plane, cylinder, sphere, or almost any irregular shape. These shape variations do not affect the refocusing characteristics of the retroreflective screen.

Third, the display system can be easily scaled. For example, more display windows can be generated by simply adding a projector.
Fourth, the display system does not have resolution limitations in conventional solutions. All images are projected on the same screen, but each image can only be viewed in the designated display window. Thus, the resolution can be as high as the resolution of the projector.
Fifth, the display system has no problem with the pile fence effect. Since the user perceives a full resolution image from a single projector in each display window, the image has no pile fence effect.

  Sixth, the display system has no problem of the image reversal effect. The inversion effect occurs when the user moves his head across the display area and perceives the right image with the left eye and the left image with the right eye. The display system does not have a repetitive display area for a particular stereo image pair, and therefore does not have an image reversal problem. Conversely, each display window displays a perspective image and any pair of images forms a 3D display. For example, in an embodiment, any two images can have a continuous perspective image forming a 3D display.

  Finally, the display system has the potential to have an infinite number of display windows. Theoretically, the display system can generate an infinite number of display windows, but the number of display windows that can be generated depends on the horizontal diffusion angle of the diffusing material, the distance from the projector to the screen, and the size of the projector.

2. Small Design Embodiment FIG. 6 depicts another embodiment of a display system according to various embodiments of the invention. FIG. 6 illustrates a display system 600 with a smaller design. The depicted display system 600 comprises a retroreflective vertical light diffusing screen 605 and a projector 610. Instead of causing the projector 610 to project the image 615 directly onto the screen 605, the projector 610 projects the image onto the beam splitter 620. The light is reflected from the beam splitter 620 or split onto the retroreflective vertical light diffusing screen 605 by the beam splitter 620. The retroreflected light, or at least a portion of the retroreflected light, passes through the beam splitter 620 to create a display window 630 where the virtual portion of the projector 635 is located. Bending the optical path using a beam splitter has at least two advantages. First, since the display window 630 is moved to the virtual position of the projector, the display window is not blocked by the projector. Second, the display system has a compact design. In the embodiment, if necessary, the optical path can be further bent by inserting the first surface mirror into the optical path. For example, a mirror can be used to bend the light path and move the projector closer to the screen.

3.2 Screen Display System Embodiment Although the embodiment depicted in FIG. 6 results in a smaller design, the image obtained in the display window is perceived to have been reduced in brightness due to energy loss as part of beam splitting. It may be. FIG. 7 illustrates another embodiment of a display system having two retroreflective vertical light diffusing screens according to various embodiments of the invention that address this light loss problem.

  FIG. 7 depicts a configuration 700 similar to the display system 600 shown in FIG. The depicted display system comprises a retroreflective vertical light diffusing screen 705A and a projector 710 having the same or similar configuration as the system 600 illustrated in FIG. As mentioned above, one problem with the display system 600 in FIG. 6 is that about half of the energy is lost each time light passes through the beam splitter. Therefore, about 25% of the light actually reaches the display window 630 of the user. One solution to this problem is to place the secondary retroreflective vertical light diffusing screen 705B in an optically mirrored position with the original screen 705A. Thus, the light reflected from the secondary retroreflective vertical light diffusion screen 705B is added to the light reflected from the primary retroreflective vertical light diffusion screen 705A forming the display window 730. Accordingly, the use of the display system 700 depicted in FIG. 7 can double the brightness of the image with respect to the display system 600 depicted in FIG.

4). Embodiment of Polarization Controlled Display System FIG. 8 illustrates yet another embodiment of a display system having a retroreflective vertical light diffusing screen according to various embodiments of the invention. The display system 800 illustrated in FIG. 8 is not only an alternative display system, but also provides another solution to the energy loss problem mentioned with respect to the system 600 illustrated in FIG.

  FIG. 8 depicts a configuration 800 that is similar to the configuration of the display system 600 shown in FIG. The depicted display system comprises a retroreflective vertical light diffusing screen 805 and a projector 810 having the same or similar configuration as the system 600 illustrated in FIG. However, as shown in FIG. 8, a beam splitter 820 having polarization sensitivity is used. Such a beam splitter has a reflectance of nearly 100% when the polarization direction of the light matches the polarization direction of the beam splitter, and a transmittance of nearly 100% when the polarization direction of the light is orthogonal to the polarization direction of the beam splitter. Have Therefore, after the light 815 is reflected toward the screen 805, the light is rotated 45 times using the quarter wave plate 840. When the light is reflected from the screen 805, it is rotated 45 times again when passing through the quarter-wave plate 840. The polarization of the obtained light is orthogonal to the polarization of the light 815 and passes through a beam splitter 820 having polarization sensitivity. Therefore, nearly 100% of the light reaches the user space in the display window 830. This method can increase the brightness of the image in the display window 830 by a factor of 4 over the configuration depicted in FIG.

  The configuration shown in Fig. 6-8 is drawn with one projector to simplify the explanation. Those skilled in the art will appreciate that additional projectors can be added to any of the disclosed systems.

5. Additional layer embodiments a) Transparent layer embodiments When an image is projected onto a retroreflective surface, most of the light is retroreflected back to the image source. However, since retroreflectors are not perfect, some light is diffused or reflected in the other direction. This diffuse or deviated reflected light can create an undesirable image called a ghost image.
An anti-reflective coating on the reflective surface reduces ghost images due to diffusion. However, this solution can be very expensive. An alternative solution presented here is a gap in the transparent medium between the diffuser and the retroreflective material. The transparent space causes the ghost image to blur on the retroreflective material, while the image on the diffuser is sharp due to the ability of the retroreflective material to focus. Furthermore, the front diffuser layer diffuses the already blurred ghost image, which makes the ghost image darker. As a result, the user sees a darker, blurred ghost image if viewed.

  As described above, when the light diffusing material is disposed in front of the retroreflective material, the light is reflected along the incident direction by the retroreflective layer and diffused in a fan shape by the light diffusing material. The resulting reflected light makes a display window. Each display window displays an image of the projector. Therefore, a plurality of display windows can be realized by combining the retroreflective light diffusing screen and a plurality of projectors. When these windows display images from different viewpoints, the multiple projector and screen system forms a three-dimensional display system. That is, by displaying a set of images captured from a plurality of viewpoints using a projector, the user can view a three-dimensional image via a formed display window. However, if there are imperfections on the screen, a ghost image can be formed.

  In the light diffuser and retroreflective screen system embodiments described above, the image is focused on the diffuser and the retroreflective material. Both the retroreflected image on the diffuser and the ghost image on the retroreflective material are sharp. The diffuse or misplaced light of the ghost image is in focus. If the ghost image is sufficiently bright, it can be viewed in the display window, which hinders the user's ability to perceive the correct image in the display window. If the ghost image is significant, the user may not be able to perceive the stereoscopic display.

  In an embodiment, a third layer is introduced between the retroreflective material and the light shaping diffuser to reduce the effect of the ghost image. This layer further diffuses the diffused light, which can darken and significantly blur the image while keeping the retroreflected image sharp.

  FIG. 9 illustrates an embodiment of a three layer retroreflective light diffusing screen 905 according to various embodiments of the invention. The screen depicted in FIG. 9 comprises a light diffuser 910 and a retroreflector 915, which are separated by a transparent medium 920. In embodiments, the width of the transparent gap was between 10-30 millimeters, but other width values can be used. The transparent medium can be, by way of example and not limitation, glass, plastic, a vacuum or near-vacuum space, or a transparent (or substantially transparent) gas.

In the projector system, the projector focuses on the first layer diffuser 910. Therefore, the image on the diffuser is clear. However, the image on the retroreflective material 915 is quite blurry because there is a space for the transparent medium 920 to diffuse before the image reaches the retroreflector 915. As shown in FIG. 9, the image point 930 on the diffuser 910 becomes a blurred region 935 on the retroreflector 915. Therefore, the image on the retroreflector is blurred.
Although most of the light is correctly retroreflected, some rays (eg, 940-x) are incompletely reflected or diffused and travel in various directions. These rays are further diffused as they pass through the diffuser 910. Therefore, when the ghost image passes through the diffuser 910, it becomes more blurred and darker. For example, light ray 940-1 travels through diffuser 910 and is further diffused by diffuser 910 to produce light ray 945 that is further dispersed and therefore darker.

  FIG. 10 illustrates a three-layer retroreflective light diffusing screen for retroreflective light according to various embodiments of the invention. Most of the light incident on the retroreflector 915 is 1005 retroreflected. Therefore, even if the image on the retroreflector 915 is blurred, the light beam retroreflected due to the retroreflective characteristic of the retroreflector 915 is focused 930 on the light diffuser 910. Therefore, the retroreflected image remains clear despite the introduction of the gap 920 formed by the transparent medium.

Since the image is in focus on the light diffuser 910, the image is correctly diffused by the diffuser 910 and diffused vertically but only slightly diffused horizontally to form the display window 1010, so that the user Sees a clear image in the display window 1010. Also, the user can see only a small amount even if he sees a very diffuse ghost image.
It is noted that the three-layer screen embodiment can also be used in the embodiments described above for the two-layer screen.

b) Embodiment of Lens Layer The lenticular sheet includes a large number of side-by-side cylindrical lenses (one-dimensional lenses). Since the lens is one-dimensional, the lenticular sheet has a light collecting ability only in one direction. Lenticular sheets are used in both transparent and reflective three-dimensional displays. For example, a lenticular reflective screen (LRS) includes two layers: a lenticular sheet and a normal diffusing surface. In the vertical direction, the light is diffused in all directions, in the horizontal direction the light is first diffused, and then condensed again on the projector by a one-dimensional lens.

  Although lenticular reflective screens have been used for three-dimensional display, lenticular reflective screens have considerable limitations. When projecting an image on a lenticular reflective screen, a set of projectors forms not only a main display area but also a side display area, as in a transparent projection system. If the additional projector is placed in the side display area outside the main display area, crosstalk between the projected images can occur, which limits the field of view of the lenticular sheet system. FIG. 11 illustrates an example of such a lenticular reflective screen configuration.

  FIG. 11 illustrates the formation of the display area from the lenticular reflective screen system 1100 and the crosstalk that may exist in such a system. The lenticular reflective screen system of FIG. 11 includes a conventional lenticular reflective screen 1105 and a set of projectors 1135. The lenticular reflective screen 1105 is a lenticular sheet 1110 and a normal diffusing surface 1115. The lenticular sheet 1110 is formed from a plurality of parallel one-dimensional lenses 1110-x. The projector set 1135 projects an image such as a multi-viewpoint image set onto the screen 1105.

  The light from the projector set 1135 forms a corresponding main display area 1120 that includes a plurality of display windows 1140. The number of display windows 1140 formed in the main display area 1120 is the same as the number of projectors arranged in the main display area 1120. The number of projectors that can be placed in the main display area is related to the width of the display window, the distance from the projector to the screen, and the field of view of the lenticular sheet. As a result of the large diffusion angle when using the normal diffuser 1115, the lenticular reflective screen 1105 has several side display areas with a corresponding display window set (eg, 1145L and 1145R) in addition to the main display area 1120 Is also formed.

  As shown in FIG. 11, light from the projector 1130 is imaged at a point 1155 through a lens 1110-1. The light is returned to form a display window 1150 in the set of display windows 1140 in the main display area 1120. Due to the large diffusion angle of the normal diffuser surface 1115, the light diffused at point 1155 is not only the lens 1110-1, but also adjacent lenses (eg, 1110-2, 1110-3, 1110-4, 1110-5, etc.) Also reach. As a result, in addition to the display window 1140 formed in the main display area 1120, a plurality of display windows (eg, 1155L and 1155R) are formed in the side display area (eg, 1125L and 1125R, respectively), one for each side display area. Is done. To simplify the figure, only two display windows (1125L and 1125R) in two side display areas (1155L and 1155R) are shown.

  When a plurality of display windows 1140 are formed in the main display area 1120 using a plurality of projectors 1135, a set of display windows corresponding to each side display area (eg, a set of display windows 1145L in the side display area 1125L, and a side surface) A display window set 1145R) is also formed in the display area 1125R.

  When another projector 1160 is placed in the side display area 1125L and projects an image on the screen 1105, the light from the projector 1160 passes through the main display window corresponding to the side display area 1125L, and the main display area 1120 and side display area 1125R Display windows may be formed and these display windows may overlap the display windows formed by the projector set 1135. For example, light from the projector 1160 in the side display area 1125L can interfere with light from the projector 1130 in the set of projectors 1135 in the main display area 1120. There is therefore crosstalk between the reflected images. If the crosstalk is substantial, it can hinder the user's ability to perceive stereoscopic images.

  Because a projector or set of projectors cannot be placed outside the main display area of the main projector set without creating a crosstalk problem, a typical LRS-based system can be very limited because the field of view of the main display area is limited. is there. FIG. 12 illustrates an embodiment of a retroreflective light diffusing screen having a lens layer according to various embodiments of the invention.

  FIG. 12 depicts a retroreflective light diffusing screen 1205, which comprises a lens layer 1220, a light diffuser 1210, and a retroreflector 1215. In the embodiment, the screen 1205 can be formed by combining the lens layer 1220 with the two-layer retroreflective light diffusion screen described above. The lens layer 1220 is configured such that the light diffuser is at the focal plane, f, of the cylindrical lens of the lens layer. Incident light that has traveled through the lens layer and the light diffuser is reflected by the retroreflective material 1215 in the direction of the incident light. The light diffuser 1210 diffuses the retroreflected light at a small angle in the horizontal direction but with a large angle in the vertical direction. A narrower horizontal diffusion angle allows light to return to only one lens, thus creating a larger display area without a side display area. As a result, the display area 1230 is larger than a typical LRS main display window 1235.

  Screen 1205 as depicted in FIG. 12 has several advantages. First, the screen 1205 eliminates the side display area, thus reducing crosstalk. Secondly, the screen 1205 increases the overall field of view and has an extended main display area. As shown in FIG. 12, the three-component screen 1205 has a main display area 1230 that is larger than the main display area of a normal lens screen such as the screen 1105 in FIG. And finally, the screen 1205 can achieve further brightness due to the additional light collection by the lens layer.

  In addition to reducing the crosstalk problem associated with the side display area, a retroreflective light diffusing screen with a lens layer addresses another crosstalk problem due to the diffuser shape of the diffuser. FIG. 13 depicts the light distribution in the display window from an embodiment of a retroreflective light diffusing screen according to various embodiments of the invention. As depicted in FIG. 13, the light distribution 1305 of the diffused light follows a Gaussian distribution. As best seen in the vertical direction, the light is brightest in the middle and loses brightness as it goes up and down. The diffused light 1305 has a Gaussian distribution also in the horizontal direction. FIG. 14 depicts an example of a cross-sectional view of diffused light 1305.

  FIG. 14 depicts a cross-sectional view of two adjacent display windows 1405-1 and 1405-2 from embodiments of retroreflective light diffusing screens according to various embodiments of the invention. As depicted in FIG. 14, two adjacent display windows 1405-1 and 1405-2 are formed from two diffused light regions 1410-1 and 1410-2 from a retroreflective light diffusing screen. The light regions 1410-1 and 1410-2 follow a Gaussian distribution, and the light passes through the light diffuser twice, so the diffusion angle is a square root that is approximately twice the diffusion angle of the light shaping diffuser.

Because light follows a Gaussian distribution, there is no clear energy barrier. In an embodiment, the display window can be defined as a region where the light intensity exceeds a threshold, such as 50% of the maximum, not a threshold or limitation. Due to the distribution as depicted in FIG. 14, some energy may leak into the adjacent display window (region 1430). By adding a lenticular lens layer to the retroreflective light diffusing screen, the lens layer focuses the diffused light to create a narrower distribution of light areas. A narrower distribution of light shapes creates a display window with a better defined boundary, reducing or eliminating crosstalk due to energy leakage. For retroreflective light diffusing screens with very small horizontal diffusion angles, the lens layer may not provide a significant advantage. However, if the display window formed by the screen exhibits substantial crosstalk, the addition of a lens layer can help to minimize crosstalk.
It is noted that a retroreflective light diffusing screen having a lens layer can also be used in the embodiments described above in connection with a two-layer screen.

c) Lens Layer and Transparent Layer Embodiments FIG. 15 illustrates yet another embodiment of a retroreflective vertical light diffusing screen according to various embodiments of the invention. FIG. 15 depicts a retroreflective light diffusing screen 1505 comprising a lens layer 1520, a transparent media layer 1525, a light diffuser 1510, and a retroreflector 1515. Such a configuration may have the advantage of reducing ghost images and reducing crosstalk. It is noted that such a screen can also be used in the embodiments described above in connection with a two-layer screen.

E. Aerial 3D Image Display Aspects of the invention include embodiments that provide an aerial display of an image, i.e., an image that floats or floats in the air. The image may be a still image or a video image. An aerial 3D image display includes a display based on a multi-display window and one or more optical focusing elements that focus light from the display based on the multi-display window to another location.

1. Aerial 3D Image Display of Display Window Consider the embodiment depicted in FIG. 16 by way of example and not limitation. FIG. 16 depicts an aerial 3D image display system according to various embodiments of the invention. As shown in FIG. 16, the display system 1600 comprises a multi-display window based display system 1615 and an optical focusing element 1620. The display system 1615 based on the multiple display window of the aerial three-dimensional image display system may be a display system based on any multiple display window. In an embodiment, the multi-display window based display system 1615 may use any of the retroreflective light diffusing screen display systems described above. For example, the screen 1605 in the display system 1615 based on multi-display windows may be any of the retroreflective diffuser screens described above. The imaging element 1620 can be a normal lens, a Fresnel lens, a concave mirror, or a combination thereof that functions as an imaging lens.

  The optical focusing element 1620 is positioned relative to the multi-display window based display system 1615 such that the multi-display window 1610 of the display 1615 is focused to another position by the optical element to form a projected display window 1640. The observer 1645 sees the three-dimensional object 1630 when it is correctly positioned to view the projection display window 1640. Since the display image 1630 is presented as on the virtual screen 1625, the three-dimensional image 1630 appears to float in the air.

  FIG. 17 illustrates ray tracing of an embodiment of an aerial three-dimensional image display system according to various embodiments of the invention. To simplify ray tracing, only the corresponding display window 1710 and the emitted light in a single projector 1715 and multi-display window are shown.

  As shown in FIG. 17, the projector 1715 projects an image or video on a screen 1705. Light rays from the projector 1715 (eg, 1745) are retroreflected by the projector and diffused by the screen 1705 with a small diffusion angle. As a result, one display window 1710 is formed at the projection point of the projector 1715.

  The reflected light (eg, 1750) continues to propagate and pass through the projector, and is collected by the imaging element 1720 beyond the imaging element 1720 to form a virtual screen 1725 and a projection display window 1740 in a three-dimensional space. At the projection point, the virtual screen 1725 is optically coupled to the physical screen 1740, and the projection display window 1740 is optically coupled to the display window 1710. By adding a projector, those images (projection display windows) are formed together with more display windows. When an observer observes the virtual screen 1725 from these projection display windows, he sees a three-dimensional image (still image or video image) floating in the air.

  FIG. 18 illustrates the position and size of a virtual screen and projection display window in an aerial 3D image display system according to various embodiments of the invention.

  The relationship between the screen 1805 and the virtual screen 1825 is governed by the lens law. The position and size of the virtual screen 1825 can be expressed according to the following equation:

  As shown in FIG. 18, the optical element 1820 is such that the display system based on the multi-display window is at a distance beyond the focal length of the lens, f (eg, 1815L), relative to the display system based on the multi-display window. Located in.

  FIG. 19 illustrates an example of an aerial 3D image display system according to various embodiments of the invention. As shown in FIG. 19, the distance from the screen 1905 to the optical condensing element 1920 is three times the focal length, f, of the imaging lens 1920. The distance from the display window 1910 to the lens is 1.5 times the focal length, f, of the imaging element 1920. The virtual screen 1925 is located at 1.5 f of the image plane, and the size is twice smaller than the size of the physical screen 1905. The projection display window 1940 is located at 3f on the image plane, and its size is twice as large as the display window 1910. One skilled in the art will appreciate that other configurations may be used.

  FIG. 20 illustrates another embodiment of an aerial three-dimensional image display system according to various embodiments of the invention. The embodiment depicted in FIG. 20 comprises a display 2015 based on a multi-display window that includes a screen 2005 and a projector (not shown) that generates a display window 2010. The system 2000 further includes a beam splitter 2020 and a concave mirror 2025, which can be a parabolic mirror or a spherical mirror. In an embodiment, the beam splitter 2020 allows light to pass from the multi-display window based display 2015 to the concave mirror 2025, the latter reflecting and condensing the light. The beam splitter 2020 receives reflected light from the concave mirror and further reflects it. Since the concave mirror 2025 collects the light, the light reflected from the concave mirror 2025 and the beam splitter 2020 generates a projection display window, and an observer 2035 located in the projection display window is floating image or multiple images 2030. It becomes possible to see. In an embodiment, the beam splitter 2020 may be partially reflective so that the viewer 2035 can see objects located beyond the beam splitter facing him. Such a configuration may be advantageous for combining floating image displays with other display or presentation materials.

  FIG. 21 illustrates yet another embodiment of an aerial 3D image display system according to various embodiments of the invention. The embodiment depicted in FIG. 21 comprises a display 2115 based on a multi-display window including a screen 2105 and a projector (not shown) that generates a display window 2110. Similar to system 2000 depicted in FIG. 20, system 2100 also includes a beam splitter 2120 and a concave mirror 2125, which can be a parabolic mirror or a spherical mirror. However, unlike the system in FIG. 20, the present system 2100 has a configuration in which a beam splitter 2120 and a concave mirror 2125 are different.

  In an embodiment, the beam splitter 2120 reflects light from the multi-display window based display 2115 to the concave mirror 2125, which reflects and focuses the light. Beam splitter 2120 receives reflected light from the concave mirror and allows at least a portion of the light to pass through to form a display window. The concave mirror 2125 collects the light from the display 2115 based on the multi-display window, so the light reflected from the concave mirror 2125 and passing through the beam splitter 2120 generates a projection display window, and an observer 2135 located in the projection window A floating image or multiple images 2130 can be seen. Unlike the configuration 2000 depicted in FIG. 20, in the configuration 2100 depicted in FIG. 21, the viewer 2135 cannot see an object located beyond the beam splitter due to the mirror 2125. Such a configuration may be advantageous to limit interference that may be caused by light or images visible in other configurations 2000.

  FIG. 22 illustrates another embodiment of an aerial 3D image display system according to various embodiments of the invention. The embodiment depicted in FIG. 22 comprises a multi-display window based display 2215 that includes a screen 2205 and a projector (not shown) that generates a display window 2210. The system 2200 also includes a Fresnel lens 2220 that collects light to create a projection display window. Thus, an observer 2235 located in the projection display window sees a floating image or images 2230. One skilled in the art will appreciate that the configuration depicted in FIG. 22 can use a mirror to fold the optical path and / or use one or more beam splitters to make the system similar to the system described above.

2. Aerial 3D Image Display of Parallel Projection Display Window Consider the embodiment depicted in FIG. 23 by way of example and not limitation. FIG. 23 depicts an aerial 3D image display system according to various embodiments of the invention. As shown in FIG. 23, the display system 2300 includes a multi-display window based display system and an optical condensing element 2320. The display system based on the multi-display window of the aerial three-dimensional image display system may be a display system based on any multi-display window. In embodiments, the multi-display window based display system may use any of the retroreflective light diffusing screen display systems described above. For example, the screen 2305 in a display system based on multiple display windows may be any of the retroreflective diffuser screens described above. The imaging element 2320 can be a normal lens, a Fresnel lens, a concave mirror, or a combination thereof that functions as an imaging lens.

  The optical concentrating element 2320 is positioned such that the display window 2310 of the display system is in the focal plane of the optical element 2320 with respect to a display system based on multiple display windows. When the projector / display window 2310 is positioned at the focal plane of the imaging element 2320, the projection display window can be considered at or at infinity. In this case, all rays from the same display window are parallel to each other. Thus, on the display, the displayed image is a set 2340 of parallel projected images. In embodiments, the position of the screen 2305 may be the same as discussed with respect to the other embodiments above.

  For display based on display windows, the observer sees a pair of stereoscopic images from the two display windows when the eye is aligned with the display window. The stereoscopic image observed when the observer stands in front of or behind the display window is a mosaiced image from multiple image sources. For the parallel projection embodiments discussed above, the display window is at infinity, meaning that the observer is always in front of the display window. Thus, the observer will see a pair of mosaiced images from multiple projectors. By viewing a pair of stereoscopic images, one for each eye, the observer can see a floating three-dimensional image.

3. Light field aerial 3D image display The embodiment in the previous section uses an aerial 3D image display system, i.e. a user floating, using a display system based on multiple display windows with one or more optical focusing elements Created a system that made it possible to see such 3D images. Each of these systems formed a display window with a perspective image.
When an observer viewed one image in one display window with one eye and another image in another display window with the other eye, a floating three-dimensional image was seen. In an alternative embodiment presented in this part, an aerial three-dimensional image display system is formed using a multi-display window based display system having one or more optical focusing elements. However, the embodiment depicted in this part is configured to form an aerial 3D image display of the light field rather than an aerial 3D image display of the display window.
As will be described in more detail below, the embodiments in this part essentially implement a transmissive projection system, so that the viewer / projector does not see two different display windows each having a perspective image. View the floating 3D image by looking at the image formed as a mosaic from the set. Such a transmissive projection system is sometimes referred to as a “light field type” display system. FIG. 24 illustrates the application of a light field type display.

  FIG. 24 illustrates the operation of a transmissive projection image display where the observer views images from different positions, or a light field display system. FIG. 24 depicts a rear projector set 2410 that projects light through a screen 2430. The points on the screen 2430 emit light of different colors and intensities depending on the angle. The light field type display 2400 generates each display (eg, 2440-A and 2440-B) according to the viewing angle by a plurality of projectors. Therefore, one image is divided into elongated pieces of the image, and a mosaic that is a perspective image of the three-dimensional display 2400 is formed by the elongated pieces of the image. For example, at position 2440-A, the observer will see one mosaic with an elongated piece of the image forming the first perspective image, but at position 2440-B, the observer (or the other eye of the same observer) Will see a different mosaic of elongated pieces of the image forming the second perspective image. Another explanation of the light field display is that for each pixel on the screen, the different rays come from different image sources, so the rays in different directions are of different colors.

  An aerial three-dimensional display system can be generated by applying this transmission projection / light irradiation field display principle to the embodiments of the present invention. By way of example and not limitation, consider the embodiment depicted in FIG. FIG. 25 illustrates an aerial three-dimensional image display system embodiment that forms a transmissive projection / light field display system according to various embodiments of the invention.

  As shown in FIG. 25, the display system 2500 includes a display system 2515 based on a multi-display window and a light collecting element 2520. The display system 2515 based on the multi-display window of the aerial 3D image display system 2500 may be a display system based on any multi-display window. In embodiments, the multi-display window based display system 2515 may use any of the retroreflective light diffusing screen display systems described above. For example, the screen 2505 in the display system 2515 based on multiple display windows may be any of the retroreflective diffusion screens described above. The optical concentrating element 2520 can be a normal lens, a Fresnel lens, a concave mirror, or a combination thereof that functions as an optical condensing element.

  The optical condensing element 2520 is a multi-display window-based display system 2515, whereas the multi-display window 2510 formed by the multi-display window-based display system 2515 effectively forms a rear projector, the light of which is the optical element 2520. Is taken to form a virtual screen 2525 at another position. The observer 2545 will see the three-dimensional image 2530 floating at the correct position to see the virtual screen 2525. Since the display image 2530 appears as shown on the virtual screen 2525, the three-dimensional image appears to float in the air.

In addition to converting the display window type display system to a transmissive projection / light field display system, this embodiment is different from the previous embodiment in that a spatially smaller system can be realized. Only the physical screen (eg, 2505) and the virtual screen (eg, 2525) are out of focus of the optical collection element. The physical screen and the virtual screen are optically coupled to each other. The display window (eg, 2510) is in focus. As a result, the floating display system becomes a transmissive projection / light field display system, which can be smaller than the embodiment in the foregoing part.
It is noted that the positions of the virtual screen and the virtual projection window can be changed by changing the positions of the actual screen and the display window as in the above-described part.

  FIG. 26 illustrates ray tracing in an embodiment of a light field aerial 3D display system according to various embodiments of the invention. In order to simplify the ray tracing, only one projector 2615 with multiple display windows and its emitted light is shown.

  FIG. 26 illustrates ray tracing of one projector in an embodiment of a light field aerial 3D display system according to various embodiments of the invention. As shown in FIG. 26, the projector 2615 projects an image or video on a screen 2605. Light rays from the projector 2615 (eg, 2645) are retroreflected by the projector and diffused by the screen 2605 with a small diffusion angle. As a result, a display window 2610 is formed at the projection point of the projector 2615, and the display window is located within the focal point 2660 of the light collecting element 2620. Reflected light rays (eg, 2650) continue to propagate, pass through the projector, are collected by the optical focusing element 2620, and form a virtual screen 2625 in three-dimensional space beyond the imaging element 2620. Unlike the previous embodiment where the projection display window is formed on the same side as the virtual screen, in this embodiment, the image of the display window is located on the same side as the projector (and display window). The image of the display window is called a virtual projection window 2640.

  The virtual screen 2625 is optically coupled to the physical screen 2605, and the virtual projection window 2640 is optically coupled to the display window 2610 at the projection point. Furthermore, by adding a projector, those images (virtual projection windows) are formed with more display windows.

  FIG. 27 illustrates the operation of a light field type aerial 3D display system according to various embodiments of the invention. This figure illustrates how the system works with multiple display windows / projectors. In FIG. 27, eight display windows 2710 are drawn, and these are imaged as eight virtual projection windows 2740. The observer 2750 sees the mosaiced image 2755 on the virtual screen 2725. For example, when observed from the viewpoint 2750, the image portion 2760, which is a vertical stripe in 2D of the observed image, is a part of the image from the virtual projection window 8, originally from the image source 8 (display window 8). Similarly, other parts come from other corresponding virtual projection windows.

  Referring now to FIG. 28, an embodiment of a light field aerial 3D display system 2800 according to various embodiments of the invention is depicted. In the depicted embodiment, the projector is placed in the main plane of the optical concentrating element 2820. As a result, the display window 2810 overlaps the main plane of the imaging lens 2820, and their images (virtual projection window 2840) are the same as the display window in both size and position. The size and position of the virtual screen 2825 can be changed by changing the size and position of the actual physical screen 2805. It is noted that this embodiment uses a thin lens model. For lens groups or thick lenses, there is a pair of main planes, and the display window and virtual projection window will each be on one main plane.

  The embodiment depicted in FIG. 28 has several advantages. First, as described above, such a configuration has a compact design. Since the projector can be in the main plane of the optical concentrating element, it requires less space, especially when compared to the embodiments in the previous part. Second, there is little or no projection window distortion. Finally, since it is necessary to optimize the lens for only one image plane, it is not so difficult to design a high quality inspection imaging lens for such an embodiment.

FIGS. 29A-C illustrate different embodiments of the arrangement of projectors and optical elements in a light field aerial 3D display system according to various embodiments of the invention. The embodiment depicted in FIGS. 29A-C may be useful in the light field type aerial 3D display system depicted in FIG.
FIG. 29A depicts an embodiment of a projector and optical focusing element configuration 2900-A. In the depicted embodiment, a set of projectors 2910 is located under a light collection element 2920-A, which can comprise one or more optical light collection elements.
FIG. 29B depicts another embodiment of a projector and optical concentrating element configuration 2900-B. In the depicted embodiment, a set of projectors 2910 is located on a light collection element 2920-A that may comprise one or more optical light collection elements.
FIG. 29C depicts yet another embodiment of a projector and optical concentrator configuration 2900-C. In the depicted embodiment, a set of projectors 2910 is located between two light collection elements 2920-A and 2920-B, each of which may comprise one or more optical light collection elements.

  FIG. 30 illustrates another embodiment of a light field type aerial 3D display system according to various embodiments of the invention. In the depicted embodiment 3000, the display window 3010 is on the same side of the optical collection element 3020 as the screen 3005, but is still in the focus of the optical element 3060-L. The size of the virtual projection window 3040 is enlarged as compared with the original display window 3010.

  FIG. 31 illustrates yet another embodiment of a light field type aerial three-dimensional display system according to various embodiments of the invention. In the depicted embodiment 3100, the display window 3110 is on the opposite side of the screen 3105 of the optical concentrating element 3120, which can be considered to be in the left focus 3160-L of the optical condensing element 3120. The size of the virtual projection window 3140 is reduced compared to the original display window 3110.

  In the above embodiment, the display window can theoretically be located from the left focus to the right infinity. The virtual projection window ranges from the left infinity when the display window is near the left focus to the right focus when the display window is near the right infinity.

F. Display System Embodiments FIG. 32 illustrates a multi-projector display system having at least one retroreflective vertical light diffusing screen according to various embodiments of the invention. In an embodiment, the system comprises a retroreflective light diffusing screen 3205 and a plurality of projectors 3210. In the depicted system 3200, the projector 3210A-x can be under the control of the computing system 3220. In an embodiment, the computing system may include a data store 3230 that stores a set of perspective images, or alternatively may be communicatively connected thereto. The computing system 3220 adjusts the display of the fluoroscopic image on the screen 3205 via the projector 3210A-x, and generates an autostereoscopic display.

  Those skilled in the art will appreciate that the system depicted in FIG. 32 includes, but is not limited to, using one or more of the configurations depicted in FIGS. 5-10, 12, 15-22, and 24-31. Understand that it can be configured differently. Any particular configuration is not critical to the present invention.

  It is noted that the present invention can be implemented in any instruction execution / computing device or system capable of processing data, including but not limited to general purpose computers and specific computers for data or image processing. The present invention can be implemented in still other arithmetic devices and systems. Further, aspects of the invention include software, hardware, firmware, or combinations thereof and can be implemented in a wide variety of forms. For example, functionality to implement various aspects of the invention is performed by components implemented in a wide variety of ways, including individual logic components, one or more application specific integrated circuits (ASICs), and / or program controlled processors. be able to. It is noted that the form in which these components are mounted is not critical to the present invention.

  FIG. 33 depicts a functional block diagram of an embodiment of an instruction execution / computing device 3300 that may be implemented in embodiments of the present invention. As shown in FIG. 33, processor 3302 executes software instructions and interacts with other system components. In one embodiment, processor 3302 is a general purpose processor such as an AMD® processor, an INTEL® processor, a SUN MICROSYSTEMS® processor, or a POWERPC®-compatible CPU (by way of example and not limitation). There can be, or the processor can be one or more applications specific to the processor. A storage device 3304 coupled to the processor 3302 provides long-term storage of data and software programs.

  Storage device 3304 may be a hard disk drive and / or another device capable of storing data, such as a magnetic or optical media (eg, diskette, tape, compact disk, DVD, etc.) drive or a solid state storage device. Storage device 3304 can store programs, instructions, and / or data for use by processor 3302. In one embodiment, programs or instructions stored in and loaded from storage device 3304 are loaded into memory 3306 and executed by processor 3302.

  In one embodiment, the storage device 3304 stores programs or instructions that implement the operating system on the processor 3302. In an embodiment, possible operating systems are UNIX®, AIX®, LINUX®, Microsoft® Windows®, and Apple® MAC (Macintosh®). )) OS included, but not limited to. In an embodiment, the operating system executes on the computing system 3300 and controls the operation of the system. In an embodiment, the data store 3330 may be a storage device 3304.

  Addressable memory 3306 coupled to processor 3302 can be used to store data and software instructions executed by processor 3302. The memory 3306 may be, for example, firmware, read only memory (ROM), flash memory, non-volatile random access memory (NVRAM), random access memory (RAM), or any combination thereof. In one embodiment, memory 3306 stores several software objects, otherwise known as services, utilities, components, or modules. Those skilled in the art will further appreciate that the memory 3304 and the memory 3306 can function in both positions on the same item. In one embodiment, one or more software components or modules may be stored in memory 3304, 3306 and executed by processor 3302.

  In one embodiment, computing system 3300 provides the ability to communicate with other devices, other networks, or both. The computing system 3300 can include one or more network interfaces or adapters 3312, 3314, coupling the computing system 3300 to communicate with other networks and devices. For example, the computing system 3300 can include a network interface 3312, a communication port 3314, or both, each of which is communicatively coupled to the processor 3302 to connect the computing system 3300 to other computer systems, networks, and devices. Can be used to link.

  In one embodiment, the computing system 3300 can include one or more output devices 3308 that are coupled to the processor 3302 to facilitate the display of graphics and text. The output device 3308 can include, but is not limited to, a projector, display, LCD screen, CRT monitor, printer, touch screen, or other device that displays information. The computing system 3300 can further include a graphics adapter (not shown) that assists in displaying information or images on the output device 3308.

  One or more input devices 3310 that are communicatively coupled to the processor 3302 may be used to facilitate user input. Input device 3310 may include, but is not limited to, a pointer device such as a mouse, trackball, or touchpad, and may further include a keyboard or keypad for inputting data or instructions to computing system 3300. it can.

  In one embodiment, computing system 3300 receives input from a scanner, copier, facsimile machine, or other computing device through communication port 3314, network interface 3312, data stored in memory 3304/3306, or input device 3310. can do.

  Those skilled in the art will understand that any computing system is not critical to the practice of the present invention. Those skilled in the art will further appreciate that some of the above-described components may be physically and / or functionally separated or combined into sub-modules.

  It is noted that embodiments of the present invention can further relate to a computer product having a computer readable medium having computer code for performing various computer-implemented operations. The media and computer code may be specially designed and constructed for the purposes of the present invention, or may be of a type known and available to those skilled in the art.

  Examples of computer readable media are: magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROMs and holographic devices; magneto-optical media; and application specific integrated circuits (ASICs). Including, but not limited to, programmable logic devices (PLDs), flash memory devices, and hardware devices that are specially configured to store or store and execute program code, such as ROM and RAM devices. Examples of computer code include machine code, such as produced by a compiler, and files containing higher level code that is executed by a computer using an interpreter.

  Embodiments of the present invention can be implemented in whole or in part as machine-executable instructions in program modules that are executed by a computer. Examples of program modules include libraries, programs, routines, objects, components, and data structures. In a distributed computing system, program modules can be physically located in local, remote, or both environments.

  While the invention is susceptible to various modifications and alternative forms, specific examples thereof are shown in the drawings and are described in detail herein. However, it will be understood that the invention is not limited to the particular forms disclosed, and conversely, the invention encompasses all modifications, equivalents, and alternatives falling within the scope of the appended claims.

  310 Light Diffusing Material, 315 Retroreflective Material, 510 Projector, 525 Display Window, 615 Image, 930 Image Point, 940 Ray, 1010 Display Window, 1205 Retroreflective Light Diffusing Screen, 1210 Light Diffuser, 1215 Retroreflector, 1220 Lens layer, 1525 transparent media layer, 2920 condensing element, 3205 retroreflective light diffusing screen, 3210 projector.

Claims (21)

A system for generating an aerial 3D image,
A multi-display window three-dimensional display system for generating a plurality of display windows;
An optical condensing element, which is located farther from the focal length of the optical condensing element and away from the plurality of display windows of the multi-display window three-dimensional display system, the multi-display window three-dimensional display system An optical condensing element that receives light from and condenses the light to form a plurality of projection display windows ;
And a screen
The plurality of projection display windows are selected from the plurality of projection display windows by viewing a first unique perspective image with a first eye in a first projection display window selected by the user from the plurality of projection display windows. The second projection display window is positioned so that the aerial three-dimensional image can be seen by looking at the second unique perspective image with a second eye ,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction A diffusion layer forming the display window,
The plurality of display windows system for generating an aerial three-dimensional image that is arranged in the second direction.   The system for generating an aerial three-dimensional image according to claim 1, wherein the optical focusing element is a lens or a concave mirror.   The system for generating an aerial three-dimensional image according to claim 2, further comprising a beam splitter positioned between the three-dimensional display system of the multi-display window and the concave mirror. The screen further comprises a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer;
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. The system for generating an aerial three-dimensional image according to claim 1 . The multi-display window three-dimensional display system has a plurality of projectors,
2. The aerial three-dimensional image according to claim 1 , wherein each of the plurality of projectors has a unique position, and is configured to project a perspective display image onto the screen to form a display window corresponding to the projection image. System to generate. The multi-display window three-dimensional display system further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer, receiving a diffuse reflection image from the light diffuser layer and condensing the diffuse reflection image to form a display window; and
A light diffuser layer located at a focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, diffusing the reflected image, and a diffusely reflected image Forming said light diffuser layer;
The aerial tertiary of claim 1 having a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image to the light diffuser layer to form a reflected image. A system that generates original images. The screen further comprises a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer;
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. The system for generating an aerial three-dimensional image according to claim 6 . A system for generating an aerial 3D image,
A multi-display window three-dimensional display system having a plurality of projectors for projecting a plurality of projection images and generating a plurality of display windows;
An optical focusing element ;
And a screen
The optical condensing element is located farther than a focal length of the optical condensing element and is separated from a plurality of display windows of the multi-display window three-dimensional display system, and from the multi-display window three-dimensional display system. Receiving light and condensing the light to form a plurality of composite images, each of the plurality of composite images being formed by a plurality of image portions from a plurality of projection images, each composite image having a unique viewpoint area That can be seen from
The aerial three-dimensional image can be viewed by an observer viewing the first perspective image with the first eye in the first viewpoint area and viewing the second perspective image with the second eye in the second viewpoint area. Is possible,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction A diffusion layer forming a display window,
The plurality of display windows system for generating an aerial three-dimensional image that is arranged in the second direction. The system for generating an aerial three-dimensional image according to claim 8 , wherein the plurality of projectors are located in a main plane of the optical condensing element. The system for generating an aerial three-dimensional image according to claim 8 , wherein the optical condensing element is located between the plurality of display windows and the screen. The screen further comprises a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer;
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. The system for generating an aerial three-dimensional image according to claim 8 . The multi-display window three-dimensional display system further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer, receiving a diffuse reflection image from the light diffuser layer and condensing the diffuse reflection image to form a display window; and
A light diffuser layer located at a focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, diffusing the reflected image, and a diffusely reflected image Forming said light diffuser layer;
9. The aerial tertiary of claim 8 , comprising a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image to the light diffuser layer to form a reflected image. A system that generates original images. The screen further comprises a transparent medium located between the two-dimensional retroreflective surface and the diffuser layer;
The transparent medium has the image out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by a diffuser layer. The system for generating an aerial three-dimensional image according to claim 12 . A method for generating an aerial 3D image, comprising:
Generating a plurality of display windows using a three-dimensional display system of multiple display windows;
From the three-dimensional display system of the multi-display window using the optical condensing element located farther from the focal length of the optical condensing element and away from the plurality of display windows of the three-dimensional display system of the multi-display window Receiving light and condensing the light to form a plurality of projection display windows,
The multi-display window three-dimensional display system has a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction A diffusion layer forming a display window,
The plurality of display windows are arranged in a second direction,
The plurality of projection display windows are selected from the plurality of projection display windows by viewing the first unique perspective image with the first eye in the first projection display window selected by the user from the plurality of projection display windows. A method of generating an aerial 3D image positioned so that the aerial 3D image can be seen by viewing a second unique perspective image with a second eye in the second projection display window. The method of generating an aerial three-dimensional image according to claim 14 , wherein the optical focusing element is a lens or a concave mirror. The screen further comprises a transparent medium positioned between the two-dimensional retroreflective surface and the diffusion layer;
The transparent medium is such that the image is out of focus on the two-dimensional retroreflective surface, and at least a portion of the defocused image that was not retroreflected by the two-dimensional retroreflective surface is diffused by the diffusion layer. The method for generating an aerial three-dimensional image according to claim 14 . The three-dimensional display system of the multi-display window further includes a screen,
The screen is
Receiving the image and condensing the image on a light diffuser layer; receiving a diffuse reflection image from the light diffuser layer; condensing the diffuse reflection image to form a display window; and
The light diffuser layer located at the focal plane of the lens layer, receiving the image from the lens layer, receiving a reflected image from the two-dimensional retroreflective surface, and diffusing the reflected image to form a diffusely reflected image When,
The aerial tertiary of claim 14 , further comprising: a two-dimensional retroreflective surface that receives the image from the light diffuser layer and retroreflects at least a portion of the image to the light diffuser layer to form the reflected image. How to generate the original image. A method for generating an aerial 3D image, comprising:
Projecting a plurality of projected images using a multi-display window three-dimensional display system that generates a plurality of display windows having a plurality of projectors;
Using the optical concentrating element located near the focal length of the optical condensing element and away from the plurality of display windows of the three-dimensional display system of the multi-display window;
The multi-display window three-dimensional display system has a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction A diffusion layer forming a display window,
The plurality of display windows are arranged in a second direction,
The step of using the optical condensing element receives light from the three-dimensional display system of the multi-display window, condenses the light to form a plurality of composite images, each composite image from a plurality of projection images Each of the composite images can be viewed from a unique viewpoint area,
The aerial three-dimensional image can be viewed by an observer viewing the first perspective image with the first eye in the first viewpoint area and viewing the second perspective image with the second eye in the second viewpoint area. A method to generate an aerial 3D image that is possible. The method of generating an aerial three-dimensional image according to claim 18 , wherein the plurality of projectors are located in a main plane of an optical focusing element. The method of generating an aerial three-dimensional image according to claim 18 , wherein the optical focusing element is located between the plurality of display windows and the screen. A system for generating an aerial 3D image,
A multi-display window three-dimensional display system for generating a plurality of display windows;
An optical condensing element, which is equal to the focal length of the optical condensing element and is spaced apart from the plurality of display windows of the multi-display window three-dimensional display system, the multi-display window three-dimensional display system An optical condensing element that receives light from and condenses the light to form the plurality of projection display windows at infinity or virtually at infinity,
The multi-display window three-dimensional display system has a screen,
The screen is
A two-dimensional retroreflective surface configured to retroreflect the image that has passed through the diffusion layer to form a reflected image;
Corresponding to the image by receiving the reflected image from the two-dimensional retroreflective surface and diffusing the reflected image, diffusing the reflected image with a large diffusion angle in the first direction and diffusing with a small diffusion angle in the second direction A diffusion layer forming a display window,
The plurality of display windows are arranged in a second direction,
The plurality of projection display windows are positioned so that a user can view the three-dimensional aerial image by viewing the first mosaic image with a first eye and the second mosaic image with a second eye. The system for generating an aerial three-dimensional image in which the first and second mosaic images are formed from at least a part of at least some of the plurality of projection display windows.