Patent Description:
In general, 3D displays are designed to provide a viewer with an image of perceived depth to generate an illusion using an image that is projected onto a planar or two-dimensional (2D) surface (e.g., a projection screen). Some 3D systems use worn devices such as glasses or goggles to separate the vision of the viewer's eyes from each other to aid in creating such an effect. In contrast, autostereoscopic displays provide a 3D visual effect without the use of a worn device or other intermediary aid beyond the surface of the screen. However, in general, many such displays provide the desired effect from a limited range of angles and/or use viewer eye tracking to maintain the effect, thereby increasing complexity and/or limiting the number of potential viewers.

US Publication No. <CIT> discloses a system for providing autostereoscopic images to a viewer surrounded by a curved lenticular projection screen. The system comprises, the curved lenticular projection screen, a projector, and a motor configured to rotate the curved lenticular projection screen.

Xiao-Qing Yin: "New Immersive Display System Based on Single Projector and Curved Surface Reflector" discloses a system comprising a curved projection screen, a projector, and a curved surface reflector. The projector is configured to project images onto the curved surface projector and the curved surface projector is configured to reflect these images onto the curved projection screen to be observed by a viewer.

<NPL>" discloses a low cost, and portable <NUM>-degree cylindrical interactive autostereoscopic 3D display system. The proposed system consists of three parts: the optical architecture (for back-projecting image correctly on the cylindrical screen), the projection image transformation workflow (for image rectifying and generating multi-view images), and the <NUM>-degree motion detection module (for identifying viewers' locations and providing the corresponding views).

One or more specific examples of the present disclosure will be described below.

The present techniques provide an autostereoscopic three-dimensional (3D) display of an image that is viewable from multiple angles and that may be implemented without the use of headgear, glasses, or a worn optical aid to create a perceived depth illusion. In some embodiments, an autostereoscopic effect may be generated by incorporating a parallax barrier or lenticular surface on or in a surface of a display (e.g., a screen). The parallax barrier or lenticules may cause one eye of a viewer to see a different image from the other eye, which, in turn, generates the illusion of perceived depth. As provided herein, a curved projection screen, for example a cylindrical display, may be used to provide viewing from multiple angles (e.g., up to <NUM> degrees around a display). Further, the disclosed techniques permit autostereoscopic images to be displayed without using complex moving parts, such as a spinning projector, a movable screen, and/or shutters. Accordingly, the disclosed techniques are less costly to manufacture while nonetheless providing <NUM> degree autostereoscopic views.

An autostereoscopic display viewable from multiple angles (e.g., viewable around a screen up to <NUM> degrees) provides opportunities to exhibit variable and/or moving content in a 3D and realistic fashion without replacing physical media or surroundings. Such displays may be used in a variety of implementations including, but not limited to, museum-like displays, projected performances, signage, etc. Additionally, amusement park rides may utilize such displays as part of a realistic surrounding in a ride, a show-piece in a queue for a ride, an immersive experience, etc..

<FIG> is a perspective view of one example of a 3D display <NUM> viewable from multiple angles to multiple viewers <NUM>. The 3D display <NUM> may include a curved projection screen <NUM> (e.g., a cylinder, half or partial cylinder, annulus, sphere, or other curved volume or portion of a curved volume) with lenticules <NUM>, or a parallax barrier, running vertically down the side of the curved projection screen <NUM>. The curved projection screen <NUM> may be of any suitable type of projection screen, for example a rear projection screen. In the depicted example, vertical lenticules <NUM> are shown on an outer surface <NUM> of the curved projection screen <NUM> and correspond to the orientation of a 3D image <NUM> with respect to the viewer(s) <NUM>. As such, the lenticules <NUM> may be arranged in any suitable orientation depending on implementation. Additionally, the lenticules <NUM> may be formed directly into the curved projection screen <NUM> (e.g., etched, molded, or embossed into the screen material) or applied as a lenticular film, and may be positioned on an inner surface <NUM> or the outer surface <NUM> of the curved projection screen <NUM>. Together, the curved projection screen <NUM> and lenticules <NUM> form a screen structure <NUM>.

To allow projected light through the curved projection screen <NUM>, the curved projection screen <NUM> may be formed from a generally transparent, translucent, and/or wavelength dependent transparent material (e.g., glass, crystal, plastic, polymer materials, etc.). In some embodiments, the curved projection screen <NUM>, with or without the lenticules <NUM>, may have a light transmittance of at least, <NUM>%, <NUM>%, <NUM>%, or <NUM>%. Additionally, the curved projection screen or screen structure <NUM> may have an opacity of less than <NUM>%, less than <NUM>%, less than <NUM>%, or less than <NUM>% to maintain clarity of the 3D image <NUM>. Additionally or alternatively, the curved projection screen <NUM> may have different transmittance, reflection, absorption, and/or opacity for light incident from the inner surface <NUM> vs the outer surface <NUM>. As such, light may have a greater transmittance projecting towards a viewer <NUM> than into the 3D display <NUM>. In one example, a viewer <NUM> may be unable to see inside the screen structure <NUM>, but the projected image may be viewed on the outer surface <NUM> of the screen structure <NUM>. Furthermore, as will be appreciated, some embodiments may include a curved projection screen <NUM> or screen structure <NUM> having a transmittance less than <NUM>% and/or an opacity greater than <NUM>%, depending on implementation.

The lenticules <NUM> may be formed as multiple lenticular lenses with a density and/or shape selected based on a desired viewing distance of the viewer <NUM>. The lenticules <NUM> or lenticular film including the lenticules <NUM> may be formed from a generally translucent or transparent material. As mentioned above with respect to the curved projection screen <NUM>, the lenticular material or screen structure <NUM> of both the lenticules <NUM> and curved projection screen <NUM> may have a light transmittance of at least, <NUM>%, <NUM>%, <NUM>%, or <NUM>% and/or an opacity of less than <NUM>%, less than <NUM>%, less than <NUM>%, or less than <NUM>%. In other embodiments, a parallax barrier including alternating opaque and translucent or transparent strips may also render a similar optical effect. As discussed herein, the lenticules <NUM> may be formed integrally with the curved projection screen <NUM> or may be applied as a film, sheet, or other structure onto the curved projection screen <NUM>. Further, the lenticules <NUM> may be implemented apart from the curved projection screen <NUM> (e.g., spaced a distance from the inner surface <NUM>, spaced a distance from the outer surface <NUM>, on or as a lens in front of a projector, or disposed on a reflector between the projector and the curved projection screen <NUM>). In the depicted example, the lenticules <NUM> are integral with or directly coupled to the curved projection screen <NUM>. In general, the lenticules <NUM> or parallax barrier operate to bend light such that the viewer's right and left eyes receive different images that produce an autostereoscopic effect. The curved projection screen <NUM> and associated lenticules <NUM> may be stationary and/or fixed in place relative to an environment.

In one example, the 3D image <NUM> (e.g., a rendering of a scene or object desired to be viewed with perceived depth) may be projected onto the curved projection screen <NUM> from a projector or other source. Multiple different slivers or portions representing partial views of the same 3D image <NUM>, corresponding to views from different perspectives (e.g., from different angles around the 3D image <NUM>), may be projected simultaneously onto the curved projection screen <NUM> and aligned with the lenticules <NUM>. The lenticules <NUM> shutter the light rays, for example in the vertical direction, so that each sliver may be observed through a narrow field of view. In some embodiments, each sliver of the 3D image <NUM> may be projected onto a single lenticule <NUM> or a grouping of lenticules <NUM>. When a viewer <NUM> looks at the 3D display <NUM>, each of the viewer's eyes may see a different sliver of the 3D image <NUM>, generating a perceived depth illusion and the 3D image <NUM>. For example, the illusion may cause the viewer to perceive that the 3D image <NUM> is an object that is located in space at a location corresponding to the enclosed space <NUM> formed by the screen. As a viewer <NUM> moves around the 3D display <NUM>, the viewed perspective of the 3D image <NUM> may change. For example, if a viewer <NUM> sees a side of a house from one angle, the viewer <NUM> may move to the opposite side of the 3D display <NUM> to see the opposite side of the house and objects behind the house not seen from the first vantage point. Additionally, different 3D images <NUM> may be displayed in succession to yield an animated (e.g., moving) 3D scene.

To help illustrate, <FIG> is an example of a partial cutaway view of the 3D display <NUM> including a stationary (e.g., relative to the curved projection screen <NUM>) projector <NUM> centered along an axis <NUM> (e.g., a center axis or other appropriate axis depending on implementation) of the curved projection screen <NUM>. In some embodiments, the projector <NUM> may be located above, below, or within the confines of the curved projection screen <NUM>. Additionally, in the depicted example, the projector <NUM> is oriented towards the point <NUM> of a conical reflector <NUM> to reflect light rays <NUM> from the projector <NUM> to the outer edge of the curved projection screen <NUM>. The conical reflector <NUM> may be centered on the axis <NUM> such that the axis <NUM> bisects the point <NUM> of the conical reflector <NUM>. As such, the projector <NUM> may be centered over the point <NUM> of the conical reflector <NUM>. Additionally, in some embodiments, the conical reflector <NUM> may extend from the top edge of the curved projection screen <NUM> to the bottom of the curved projection screen <NUM>, as illustrated. However, different size (e.g., larger and smaller) conical reflectors <NUM> may also be used, depending on implementation, to reflect the light rays <NUM> from the projector <NUM> to the curved projection screen <NUM>. The conical reflector <NUM> serves to unwrap the 3D image <NUM> from a planar output of the projector <NUM> and yield a panoramic view of up to <NUM> degrees around the curved projection screen <NUM>. The conical reflector <NUM> may be made of any suitable reflective material (e.g., having a reflectivity of greater than <NUM>%, greater than <NUM>%, or greater than <NUM>%) such as Mylar, aluminum, silver, tin, etc. In one example, the conical reflector <NUM> may include a glass or acrylic mirror. In some embodiments, the curved projection screen <NUM> may be solid with the conical reflector <NUM> built-in, or the curved projection screen <NUM> may be hollow, forming, for example, an annulus around the conical reflector <NUM>. As stated above, the curved projection screen may be one of multiple shapes (e.g., a cylinder, half or partial cylinder, annulus, sphere, or other curved volume or portion of a curved volume). As such, the geometry and placement of the conical reflector <NUM>, projector <NUM>, and lenticules <NUM> may be altered depending on implementation. For example, if the curved projection screen <NUM> makes up a half cylinder, a halved conical reflector <NUM> may be used to reflect the light rays <NUM> to the curved projection screen <NUM>. Additionally or alternatively, the projector <NUM> may be aimed at a point other than point <NUM> of the conical reflector <NUM> depending on the implementation.

In some embodiments, a controller <NUM> may assist in processing images, prior to projection, and/or controlling the projector <NUM>, as depicted in the block diagram showing a control system <NUM> of <FIG>. The controller <NUM> may include a processor <NUM>, memory <NUM>, and/or an input/output (I/O) interface <NUM> to receive, process, and/or output image data for the 3D display <NUM>. Processed imagery may be communicated from the controller <NUM> to the projector <NUM>, and a light source <NUM> within the projector <NUM> may output light rays <NUM> to the conical reflector <NUM> and curved projection screen <NUM> for viewing. The processor <NUM> may include one or more general purpose microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable logic arrays (FPGAs), or any combination thereof. The memory <NUM> may store data to be processed by the processor <NUM>, and may include one or more tangible, non-transitory, computer- readable mediums. For example, the memory <NUM> may include random access memory (RAM), read only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, and/or the like. Additionally, the light source <NUM> may be of any suitable type (e.g., laser, incandescent bulb, light emitting diode (LED), liquid crystal, etc.) depending on implementation.

In some embodiments, the controller <NUM> may pre-process the 3D image <NUM> and store processed images in memory <NUM> for projection at a later time. Furthermore, the controller <NUM> may be implemented together or separately from the projector <NUM>. Depending on implementation, a controller <NUM> separate from the projector <NUM> may process imagery to be projected and a second controller may directly control the projector <NUM>.

The processing of a 3D image <NUM>, or a collection of 3D images <NUM> (e.g., to show animation) may depend upon one or more factors subject to a desired implementation. The 3D image <NUM> to be displayed and/or the projector <NUM> may be calibrated based at least in part on such factors. For example, the number of renderings of a 3D image <NUM> from different angles (e.g., slivers of the 3D image <NUM>) may vary depending on desired fidelity, number of lenticules <NUM>, and/or size of the curved projection screen <NUM>. In some embodiments, a curved projection screen <NUM> encompassing <NUM> degrees (e.g., a cylindrical screen) may utilize at least <NUM>, at least <NUM>, or at least <NUM> renderings of the 3D image <NUM> from different angles. Furthermore, the number of lenticules <NUM> and/or size of the curved projection screen <NUM> may vary from a small exhibit (e.g., less than a <NUM> cubic foot (<NUM> cubic meters) in volume) to a life size display (e.g., greater than <NUM> cubic feet (<NUM> cubic meters) in volume). Additionally, lenticules <NUM> generally rely on multiple curved surface ridges to shutter the light rays <NUM> for the viewer <NUM>. In some embodiments, a viewer's distance from the 3D display <NUM> may affect the perceived 3D effect by changing which slivers of the 3D image <NUM> are seen by each of the viewer's eyes. As such, the projected image may be calibrated based on an estimated, average, and/or set viewing distance. Further, the multiple slivers of the 3D image <NUM> may be "wrapped" or together as a single image to be output by the projector <NUM>, such that when projected onto the conical reflector <NUM>, the slivers are "unwrapped" and reflected onto the circumference of the curved projection screen <NUM>. Such wrapping and unwrapping may correspond to the geometries of the conical reflector <NUM> and the curved projection screen <NUM> as well as the relative distances between the projector <NUM>, conical reflector <NUM>, and curved projection screen <NUM>.

To help further illustrate, <FIG> is a flowchart <NUM> of an example process for generating a 3D image <NUM> viewable from up to <NUM> degrees around a curved projection screen <NUM>. As indicated above, one or more implementation factors may be determined corresponding to the 3D display and/or the environment (e.g., viewing distance) (process block <NUM>). Multiple renderings of at least one 3D image <NUM>, corresponding to different viewing angles around the 3D display <NUM>, may be calibrated (e.g., processed and/or formatted) for display by the 3D display <NUM> (process block <NUM>) based at least in part on the implementation factors. The calibrated multiple renderings of the at least one 3D image <NUM> may be output to the projector <NUM> (process block <NUM>) and projected simultaneously onto a conical reflector <NUM> (process block <NUM>). If multiple 3D images <NUM> are to be displayed in sequence to animate the scene, the calibrated multiple renderings of a single 3D image <NUM> (e.g., an image frame) may be projected simultaneously followed by the calibrated multiple renderings of a subsequent frame. The multiple renderings of the at least one 3D image <NUM> may then be presented on the curved projection screen <NUM> viewable through the multiple lenticules <NUM> (process block <NUM>) to yield an autostereoscopic rendition of an object or scene.

Although depicted in <FIG> as a 3D display <NUM> to be viewed from around the curved projection screen <NUM>, a 3D surround display <NUM> may include a curved projection screen <NUM> that at least partially encompasses the viewer <NUM>, as shown in <FIG>. In some embodiments, the viewer <NUM> may be partially or completely surrounded by the curved projection screen <NUM>, providing an immersive experience. Relative to the viewer <NUM>, the conical reflector <NUM> may be positioned at a location outside of the enclosed space <NUM> formed by the curved projection screen <NUM>, allowing the light rays <NUM> to travel to the curved projection screen <NUM> from the projector. Additionally, the conical reflector <NUM> may be truncated corresponding to an end (e.g., floor or ceiling) of the curved projection screen <NUM>. For example, the conical reflector <NUM> and/or curved projection screen <NUM> of the 3D surround display <NUM> may form a half cone and half annulus (e.g., forming <NUM> degrees of an annulus) respectively, a full cone and full annulus respectively, or any suitable amount of solid angle around the viewer <NUM>. As discussed above in regards to the 3D display <NUM>, the projector <NUM> of the 3D surround display <NUM> may be above the curved projection screen <NUM> or below depending on implementation, and the calibrating/processing of the 3D image <NUM> may include the same and/or similar factors.

While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes.

Claim 1:
An image projection system, comprising:
a curved projection screen (<NUM>), wherein the projection screen (<NUM>) forms a
full annulus and is translucent or transparent, wherein the curved projection
screen (<NUM>) is configured to completely surround a viewer (<NUM>);
a plurality of lenticules (<NUM>) disposed on or in the projection screen (<NUM>);
a projector (<NUM>) configured to project a plurality of images onto the projection screen (<NUM>), wherein the plurality of images comprise a plurality of views of a scene, wherein the projector (<NUM>) is configured to simultaneously project the plurality of images to generate a three-dimensional display (<NUM>) of the scene, wherein the projector (<NUM>) is configured to project the plurality of images from a position outside of an enclosed space (<NUM>) formed by the projection screen (<NUM>), and wherein the projector (<NUM>) is above or below the curved projection screen (<NUM>);
a conical reflector (<NUM>) configured to reflect the plurality of images from the projector (<NUM>) onto the projection screen (<NUM>), wherein the conical reflector (<NUM>) is positioned at a location outside of the enclosed space (<NUM>) formed by the projection screen (<NUM>), wherein the conical reflector (<NUM>) forms a full annulus around the viewer (<NUM>),
wherein the projection screen (<NUM>), the plurality of lenticles (<NUM>) and the projector (<NUM>) are stationary relative to an environment of the image projection system,
wherein the image projection system is configured to display multiple three-dimensional displays of the scene in sequence to animate the scene, the plurality of images comprising a first plurality of images corresponding to a first frame of the scene and a second plurality of images corresponding to a second frame of the scene that is subsequent to the first frame, the projector (<NUM>) being configured to project the second plurality of images after projecting the first plurality of images to simulate movement within the scene.