Omnidirectional video display assembly and method of displaying an omnidirectional video

Abstract

The invention provides an omnidirectional video display assembly (10) comprising: at least one video display (11, 12); an optical limiter associated with the at least one video display (11, 12); a mount (14, 15, 16, 17) for mounting the at least one video display (11, 12) and being rotatable about an axis; and a drive (21) associated with the mount (14, 15, 16, 17) and adapted to provide rotational drive to the mount (14, 15, 16, 17). The optical limiter may comprises a cylindrical screen (18) disposed around the at least one video display (11, 12), the cylindrical screen (18) comprising one or more elongate slit (19), each being disposed in front of a respective video display (11, 12).

Description

[0001] OMNIDIRECTIONAL VIDEO DISPLAY ASSEMBLY AND METHOD OF DISPLAYING AN OMNIDIRECTIONAL VIDEO

[0002] FIELD OF INVENTION

[0003] The present invention relates to an omnidirectional video display assembly and method of displaying an omnidirectional video. More particularly, the invention relates to a full-colour high-definition omnidirectional holographic video display assembly that is that is capable of presenting the same full-colour high- definition image in all directions simultaneously to multiple viewers and associated methods of displaying a video.

[0004] BACKGROUND ART

[0005] Screens are all throughout current society, from phones to televisions and beyond. A major limitation of all these screens is that they can only be viewed from the front. Moreover, the effective viewing angle is less than 180 degrees as the image becomes difficult to comprehend when viewed at a large angle. Various proposals for holographic displays have been proposed, yet all of these have major drawbacks that have prevented their adoption beyond the most niche cases. These include the complexity of the display and its associated cost, size of the display and / or size of the additional components required to support the display, image resolution, image quality / stability, full-colour reproduction, the use of consumables such as water for misting, etc. Even in the theoretical best-case of imagining a hypothetically perfectly reproduced “floating head in space”, three-quarters of viewers do not receive an adequate view as they are viewing either the back or the sides of this floating head, not the face.

[0006] It would be advantageous if a video display could be provided that can be viewed from all directions simultaneously. Furthermore, it would be particularly advantageous if the display was of high image quality, show full colour, not require consumables to operate, and not require bulky additional components to produce the image. The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate exemplary technology areas where some embodiments described herein may be practiced.

[0007] Various aspects and embodiments of the invention will now be described.

[0008] SUMMARY OF INVENTION

[0009] As mentioned above, the present invention relates generally to an omnidirectional video display assembly and method of displaying an omnidirectional video. More particularly, the invention relates to a full-colour high-definition omnidirectional holographic video display assembly that is that is capable of presenting the same full-colour high-definition image in all directions simultaneously to multiple viewers and associated methods of displaying a video.

[0010] According to one aspect of the invention there is provided an omnidirectional video display assembly comprising: at least one video display; an optical limiter associated with the at least one video display; a mount for mounting the at least one video display and being rotatable about an axis; and a drive associated with the mount and adapted to provide rotational drive to the mount.

[0011] As used herein, the term “optical limiter” refers to a component adapted to limit the direction of light emitted from an associated video display.

[0012] The video display assembly may include one, two or three or more video displays. In a preferred embodiment the assembly comprises two video displays disposed back-to-back on said mount. The video display may take any suitable form, such as mobile phones, monitors or televisions. Preferably, the video displays are tablets. Two tablets is convenient as the tablets balance each other out when placed in a back-to back orientation, noting that phones and tablets are not balanced about a centre axis. For example, placing two tablets back-to-back results in a battery on the left side of the pair in one tablet being counterbalanced by a battery on the left side of the pair in the other tablet.

[0013] Viewing of the screens occurs through an optical limiter. Limiting of the image viewed may be through one or more slits, or through a microscopic angle filter or privacy screen, or through other means to limit the light emitted from the screen to a roughly perpendicular angle. Preferably, the optical limiter comprises a screen disposed in front of and spaced from a respective video display, the screen comprising an elongate slit disposed in front of the respective video display through which light from the respective video display can pass. More preferably, the screen comprises a cylindrical screen disposed around the at least one video display, the cylindrical screen comprising one or more elongate slit, each being disposed in front of a respective video display. According to this embodiment, the video display assembly may further comprise a pair of end plates adapted to close ends of the cylindrical screen thereby enclosing the at least one video display. It is envisaged that in alternative embodiment the optical limited comprises a collimating lens. Furthermore, it is envisaged that a collimating lens may be additionally provided as a focusing aid to increase brightness, depending on its specifications.

[0014] The mount may be adapted to rotate by any suitable means. For example, the mount may be a carousel containing the drive that can be disposed on a surface and which mounts the video display(s) and associated optical limiter. In preferred embodiments, the mount comprises plurality of mounts disposed on inner surfaces of the pair of end plates that close the ends of the cylindrical screen. In that regard, the video display assembly preferably further comprises a central axle connected to the drive and extending between the pair of end plates. The drive may be any drive that can translate rotational drive to the mount. In preferred embodiments the drive comprises an electric motor. The rotating mechanism may be secured at one or both ends of the axle shaft, or it may be secured by bearings or other means at or further towards the circumference. Its rotational rate may be fixed, variable, or offer different speeds to choose between. Careful selection of the motor and bearings is important to minimise noise. For example, components designed for robotics competitions may provide advantageous outcomes.

[0015] For safety reasons, the whole rotating mechanism is preferably be contained. On smaller, slower-spinning, phone-sized cylindrical displays, this may not be necessary. On larger displays, a second fixed outer cylinder of clear plastic / acrylic will protect fingers and safely contain the device were it to fail. To that end, in a preferred embodiment the video display assembly further comprises a protective housing disposed about said at least one video display and said optical limiter. Preferably the protective housing comprises a transparent housing or a cage.

[0016] According to another aspect of the invention there is provided a method of displaying an omnidirectional video comprising: displaying a video on at least one video display; and rotating the at least one video display and an associated optical limiter about an axis at a rotational speed sufficient to achieve a persistent view of the video about 360 degrees.

[0017] Preferably, the video is displayed on two video displays disposed back-to-back and the optical limiter comprises a cylindrical screen disposed around the video displays and comprises two elongate slits, each being disposed in front of a respective video display. According to this embodiment, the video displays and cylindrical screen are preferably rotated at a speed of from 800-1000 rpm, more preferably about 900 rpm. The rotation preferably achieves an effective refresh rate of about 30Hz. As will be appreciated from the following more detailed description of the invention, the video data for the video to be displayed is preferably transmitted to the at least one video display wirelessly.

[0018] It is envisaged that a version of the assembly could be made very cheaply by excluding the video display(s), facilitating mounting of a personal video display, such as a phone or tablet. It would then be up to the user to select a phone or tablet that will work effectively in the assembly. This is particularly of use if using only a single screen.

[0019] To that end, according to another aspect of the invention there is provided a video display mount comprising: a mount for mounting at least one video display and being rotatable about an axis; an optical limiter adapted to be associated with the at least one video display to be mounted on the video display mount; and a drive associated with the mount and adapted to provide rotational drive to the mount.

[0020] BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[0021] To further clarify various aspects of some embodiments of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It should be appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting on its scope. The invention will be described and explained with additional specificity and detail through the accompanying drawings in which:

[0022] FIG. 1 illustrates an exploded view of an omnidirectional video display assembly according to an embodiment of the invention. FIG. 2 illustrates the rotating components of the video display assembly of Figure 1.

[0023] FIG. 3 illustrates the rotating components of the video display assembly of Figure 2 excluding the cylindrical optical limiter.

[0024] FIG. 4 illustrates internal faces of the end plates associated with the cylindrical optical limiter of the video display assembly of Figure 2.

[0025] FIG. 5 illustrates an omnidirectional video display assembly according to an alternative embodiment of the invention.

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, this specification will describe the present invention according to the preferred embodiments. It is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned without departing from the scope of the appended claims.

[0028] Referring to Figures 1 to 4, a video display system 10 is provided that is fullcolour, high-definition, omnidirectional, bill-boarding holographic, without the use of consumables, and without bulky accompanying additional support components. Two self-contained tablets 11 , 12 are secured back-to-back around a central axle 13. The tablets 11 , 12 are secured in place by mounts 14, 15 located on inner surfaces of end plates 16 and 17 that seal ends of a black light-blocking cylindrical optical limiter 18 (shown as a transparent cylinder for convenience). The imagery displayed on the tablets 11 , 12 is duplicated, and the video data is transmitted to the tablets 11 , 12 wirelessly. An elongate viewing slit 19, 20 is located perpendicularly opposite each tablet 11 , 12. The whole central mechanism spins around the central axle 13 driven by an electric motor 21 at a rate fast enough to achieve the persistence of vision around 360 degrees. With two tablets 1 1 , 12, a rotational speed of 900 rpm achieves an effective refresh rate of 30Hz. Persons standing anywhere around the video display system 10 will see segments of light through the viewing slits 19, 20, passing across the rotating tablet 11 , 12 quickly enough to make up the full image. All viewers see the same image. For instance, one of these video display systems 10 in the middle of a meeting room table may enable a video conference where all participants in the room simultaneously see the caller's face not only from the front but making eye contact with them.

[0029] Referring to Figure 5, an embodiment of a video display assembly 50 is illustrated that includes the components 51 previously described mounted within a protective cage 52.

[0030] Video Displays

[0031] The assembly’s video displays (i.e., screens) advantageously have almost no flicker / PWM, or the persistence-of-vision effect will not be optimal. Almost all OLED displays and a number of LCDs have some flicker. It has been found that a model of tablet that has been tested to have no detectable flicker up to at least 3.8MHz will provide optimal results.

[0032] The assembly’s video displays also need to be very bright. If only two 5-degree slits are used, this limits the assembly to 1 / 36th the video display's normal brightness. A model of a tablet with very high maximum brightness that is viewable outdoors is therefore recommended. This can be partly compensated for with an ultra-black optical limiter to increase the effective contrast ratio. For example, a Musou Black fabric may be used. It is envisaged that black plastic will be suitable for commercial products.

[0033] The assembly’s video displays need to have a good viewing angle, as any colour or brightness tint when viewing the screen at an angle will show up as a permanent tint at the edges of the display. A model of a tablet with a wide viewing angle is considered most appropriate. Sending power & video data over a physical connection is possible, but may be difficult and expensive to achieve correctly, and may involve consumable components such as brushes. In the exemplified embodiments the video data was sent wirelessly, and batteries in the tablets were charged between uses. It is envisaged that wirelessly charging these batteries or eliminating them entirely by constantly delivering power may also be possible. This would reduce both weight and costs of a finished product.

[0034] The assembly’s video displays need to be able to tolerate the centripetal force it experiences. Bigger displays spinning faster will experience more force. The exemplified embodiment uses a vertical / portrait orientation for the tablets to maximise the effective display area versus forces experienced, but they could also be landscape / horizontal orientated, or be square. In the exemplified embodiment, a model of tablet that was more rugged than a standard tablet was used to ensure it could survive the force of spinning.

[0035] The only limits on size are withstanding the centripetal force. A phone-sized screen is relatively easy, as is a tablet. A computer-monitor-sized screen may also be possible, as might a television-sized display, but this option would become quite bulky and the distortion from spinning would likely become a visible issue.

[0036] A faster frame rate can be obtained with a smaller screen before reaching the centripetal force limits. This presents an option for product variance for different use cases, with smaller higher-frame-rate displays and larger lower-frame-rate displays.

[0037] The video display may be of any type of technology that can be used to display a video image, with LCD being the technology used in the exemplified embodiment. They may be back-lit, and / or transflective, and / or front-lit. As noted above, the video display should be bright enough so that its output is still considered reasonably bright through the optical limiter. The animation shown on the video displays may be presented as-is, or it may be modified to account for distortion caused by the video display's rotation, or it may be modified to create intentional distortion for effect.

[0038] Optics may be used in front of the video displays and / or as part of the optical limiter to reduce the distortion caused by the video display's rotation and / or increase brightness.

[0039] With an even number of screens, a 3D effect may be obtained with opposing polarising film installed on each screen plus the viewer wearing matching polarising glasses, or through the use of shutter glasses synchronised to the device's rotation, or other 3D viewing techniques. A 3D effect may also be obtained when using any number of screens by displaying an Anaglyph- encoded video or other similar encoding techniques.

[0040] The video displays may be powered through local batteries that are recharged when the display isn't spinning, through wireless power transmission, or a physical connection such as a brush or slip ring.

[0041] The data for the video displays may be transmitted wirelessly, or through a physical connection such as a brush or slip ring.

[0042] With careful timing synchronisation, it would be possible to display a slightly different image on each screen, to double the effective frame rate displayed. This means a screen rotating 30 times a second could display 60 images per second. This would require custom-integrated hardware and not just two generic tablets. The same technique could also be used with 3 or more screens, not just 2, to also get faster effective frame rates.

[0043] Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers, but not the exclusion of any other step or element or integer or group of steps, elements or integers. Thus, in the context of this specification, the term “comprising” is used in an inclusive sense and thus should be understood as meaning “including principally, but not necessarily solely”.

[0044] Unless the context requires otherwise or specifically stated to the contrary, integers, steps or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.

[0045] It will be appreciated that the foregoing description has been given by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons of skill in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth.

Claims

CLAIMS1 . An omnidirectional video display assembly comprising: at least one video display; an optical limiter associated with said at least one video display; a mount for mounting said at least one video display and being rotatable about an axis; and a drive associated with said mount and adapted to provide rotational drive to said mount.

2. A video display assembly according to claim 1 , comprising two video displays disposed back-to-back on said mount.

3. A video display assembly according to claim 2, wherein said video displays are tablets.

4. A video display assembly according to any one of the preceding claims, wherein said optical limiter comprises a screen disposed in front of and spaced from a respective video display, said screen comprising an elongate slit disposed in front of said respective video display through which light from the respective video display can pass.

5. A video display according to claim 4, wherein said screen comprises a cylindrical screen disposed around said at least one video display, said cylindrical screen comprising one or more elongate slit, each being disposed in front of a respective video display.

6. A video display assembly according to any one of the preceding claims, wherein said optical limiter comprises a cylindrical screen disposed around said at least one video display, said cylindrical screen comprising one or more elongate slit, each being disposed in front of a respective video display, said video display assembly further comprising a pair of end plates adapted to close ends of said cylindrical screen thereby enclosing said at least one video display.

7. A video display assembly according to claim 6, wherein said mount comprises a plurality of mounts disposed on inner surfaces of said pair of end plates.

8. A video display assembly according to claim 6 or 7, comprising a central axle connected to said drive, and extending between said pair of end plates.

9. A video display assembly according to any one of the preceding claims, wherein said drive comprises an electric motor.

10. A video display assembly according to any one of the preceding claims, further comprising a protective housing disposed about said at least one video display and said optical limiter.

11. A video display assembly according to claim 9, wherein said protective housing comprises a transparent housing or a cage.

12. A method of displaying an omnidirectional video comprising: displaying a video on at least one video display; and rotating said at least one video display and an associated optical limiter about an axis at a rotational speed sufficient to achieve a persistent view of said video about 360 degrees.

13. A method according to claim 11 , wherein said video is displayed on two video displays disposed back-to-back and wherein said optical limiter comprises a cylindrical screen disposed around said video displays and comprising two elongate slits, each being disposed in front of a respective video display.

14. A method according to claim 12, wherein said video displays and cylindrical screen are rotated at a speed of from 800-1000 rpm, preferably about 900 rpm.

15. A method according to claim 13, wherein said rotation achieves an effective refresh rate of about 30Hz.

16. A method according to any one of claims 11 to 14, wherein video data for said video to be displayed is transmitted to said at least one video display wirelessly.

17. A video display mount comprising: a mount for mounting at least one video display and being rotatable about an axis; an optical limiter adapted to be associated with the at least one video display to be mounted on the video display mount; and a drive associated with the mount and adapted to provide rotational drive to the mount.

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