GB2539651B

GB2539651B - Display system

Info

Publication number: GB2539651B
Application number: GB1510802.0A
Authority: GB
Inventors: Ezra Jacob
Original assignee: Mystery Tech LLP
Current assignee: Mystery Tech LLP
Priority date: 2015-06-19
Filing date: 2015-06-19
Publication date: 2019-11-06
Anticipated expiration: 2035-06-19
Also published as: GB2539651A; GB201510802D0

Description

Display System

The present disclosure relates to a display system. In particular to a display system that is suitable for use in displaying subtitles or for use in providing a privacy mode for a personal electronics device.

Currently there are two main types of subtitle captioning: 1) "Open Captions", which are subtitles which form part of a movie and are seen by the whole audience; and 2) "Closed Captions", where the captions are available for viewing by employing an additional viewing device such as a mirror, a hand held display device or a head mounted display. Prior art closed captioning systems are explained in more detail below. FIG.3 shows a closed captioning system disclosed in US 5570944, which comprises a small reflective window for use by a user to view text or subtitles, synchronized to the movie and displayed, inverted, on the back wall, without disturbing the other members of the audience. FIG.4 shows an alternative closed captioning system in the form of electronic viewing glasses. Captions are synchronized with the movie and coloured text is projected via tiny projectors on to the glasses, which appears in front of the viewer, such that the movie is over-laid with text or wherever the viewer looks. FIG.5 shows a further alternative closed captioning system in which captions are displayed on a hand-held device.

These prior art arrangements offer significant limitations. In particular, the arrangements of FIGS.3 and 4 require the viewer to glance back and forth, from the devices hundreds of times during the duration of a movie, which is liable to cause near/far-focussing fatigue.

The present invention was realised as a result of work to provide an improved subtitle system.

According to the present invention in a first aspect, there is provided a display system as recited by Claim 1.

The remote polarising filter preferably comprises one or both lenses of a pair of glasses.

In accordance with the present invention, a closed captioning system may be provided, which allows a member of the audience to choose whether they want to watch the movie (or otherwise) with or without the subtitles. The system overcomes the problem of near/far focusing as the text may be provided at the same focal depth as the main screen, but more importantly, remains invisible to viewers who do not want to see the subtitles. In addition or as an alternative to the text displays showing subtitles, a "signing screen" may be provided, which comprises a screen functioning in the same manner as the subtitle display but displaying an individual performing sign language rather than text. Of course, the signing screen may show any alternative desired video, images, text or otherwise.

The system may be used by audiences at other venues where there are relatively large screens, such as in bars, clubs, schools, and also by domestic users at home. In this instance the subtitling and/or signing screen(s) which complement the main screen, can be fed by different means to that which is used in a cinema. The system may further be used in theatres for providing discrete subtitles to audience members. Also, the system may provide different viewing options for domestic viewers who may want the subtitle and/or signing screen(s) visible at certain times or all of the time.

Non-limiting embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG.l shows a simplified and exploded view of a conventional LCD or TFT flat panel monitor; FIG.2 shows a simplified and exploded view of an LCD or TFT flat panel monitor modified in accordance with the principals of the present invention by removal of the front polarizer 4, along with a pair of polarizing viewing glasses 5, which unlike 3D glasses have the same polarizer filter in both eyes to compensate for removal of the polariser from the flat panel monitor; FIGS.3 to 5 show prior art closed captioning systems, as discussed above; FIG.6 shows a movie screen according to an embodiment of the present invention comprising a subtitling wall below the movie screen that consists of two rows of monitors; FIG.7 shows an alternative movie screen according to an embodiment of the present invention comprising a subtitling wall below the movie screen and a signing wall to the right of the movie screen; FIG.8 shows a further alternative movie screen according to an embodiment of the present invention comprising two walls for subtitles and two walls for signing; FIG.9 shows a dual subtitle cinema system according to an embodiment of the present invention with dual signing walls and 3 types of viewing glasses, including a reversible type, wherein the labels in bold in each square allow for easy selection between the two subtitle and signing screen systems; FIG.10 shows a reversible pair of polarized glasses, wherein, in the state shown, subtitle screen A and signing screen A would be viewable through these glasses, and a small flag in the middle rotates around a central pivot, displaying a small label, A or B, and wherein the polarized lenses correspond to the subtitle screen and signing wall that the viewer chooses to view; FIG.11 shows the reversible pair of polarized glasses of FIG.10 in mid transition between A and B; FIG.12 shows the reversible pair of polarized glasses of FIG.10 in the second configuration, wherein, in this state, subtitle screen B and signing screen B would be viewable through these glasses; FIG.13 shows 4 monitors in a row to form a segmented display according to an embodiment of the present invention; FIG.14 shows a full system according to an embodiment of the present invention utilising monitor arrays as shown in FIG.13; FIG.15 shows an example of a privacy system according to an embodiment of the present invention which shows a laptop with front polarizer removed and a pair of viewing glasses having the same polarizer in each eye, wherein the polarizers in the glasses are the same as the front polarizer which has been removed; FIG.16 shows an example layout of how a passive 3D display monitor 26 with the front polarizer 27 removed may be used to show subtitles during a 3D movie, viewed through standard circular polarized 3D cinema glasses; FIGS.17. A to F show variations of polarized viewing glasses for use with embodiments of the present invention: FIG.17A shows a pair of linear polarized viewing glasses, such as those usually found in theme parks; FIG.17B shows a pair of standard SD cinema circular polarized glasses generally known as Real3D glasses; FIG.17C shows one embodiment of subtitle glasses used for viewing captions wherein the polarization direction is diagonal and the polarizer is the same in each eye; FIG.17D shows another embodiment of subtitle glasses used for viewing captions on monitors where the polarization direction is horizontal and the polarizer filter is the same in each eye; FIG.17E shows a bi-focal, dual purpose, configuration of circular polarized 3D viewing glasses overlaid with a section of horizontal polarizer to view a subtitle monitor and a 3D movie; FIG.17F shows a bi-focal, dual-purpose, configuration of circular polarized 3D viewing glasses with a split section of horizontal polarizer to view a subtitle monitor and a 3D movie; FIG.18G, H and J, show exemplarily, where the split may occur for a bi-focal, dual-purpose, pair of 3D circular glasses for use with embodiments of the present invention, where one part is for viewing the 3D movie and the other part is for viewing a subtitle monitor: FIG.18G is set at 50/50; FIG.18H is set at around one third; and FIG.18J is set at around 25% split; FIG.19 shows a rear perspective view of a pair of bi-focal, subtitle, 3D glasses for use with embodiments of the present invention; FIG.20 shows a diagrammatic side view of a viewer looking through a pair of bi-focal subtitle 3D glasses where the top half perceives the 3D movie and the lower portion views the subtitles on the subtitle monitor below the movie screen, in accordance with an embodiment of the present invention; FIGS.21K, L and M show side views of three variations of how the polarizer for reading the subtitles, may be placed in conjunction with the circular polarizer for viewing the 3D movie, in accordance with embodiments of the present invention: FIG.21K shows a split configuration where there is no overlap, hence, the viewer perceives a bright image from the 3D movie and the subtitles; FIG.21L shows that the horizontal polarizer is placed on top of the circular polarizer which allows for viewing both, the 3D movie and the subtitles, however, this configuration results in a loss of light when viewing the subtitles; and FIG.21M shows an arrangement where the polarizers required for viewing the subtitles are fixed externally on to the glasses frame, which allows for a quick and simple modification to standard 3D circular cinema glasses; FIG.22 shows, in exploded view, the parts usually contained within a standard video monitor; FIG.23 shows, in exploded view, the parts of a modified display according to an embodiment of the present invention, which is suitable for displaying subtitles; FIG.24 shows a display screen for use in a subtitle display system according to the present invention, which features a horizontally slideable front polariser; FIGS.25A, B, C and D show alternative display screens usable in a subtitle display system according to the present invention, which all feature movable front polarisers that may be moved into and out of position in front of the display screens by pivoting of sliding movement; and FIG.26 shows a display screen for use in a display system according to the present invention, which features a rollable front polariser.

Note: The depiction of the polarizer filter material and direction of polarization shown in the relevant figures detailed above has been simplified for clarity; hence the actual lines shown on the polarizer filters are not present in reality.

Embodiments of the present invention may utilise TFT (thin film transistor) or LCD (Liquid Crystal Display) technology. As will be readily appreciated by those skilled in the art, LCD and TFT displays share similarities in the way they are constructed.

With reference to Figure 1, there is shown an exploded view of a conventional flat panel display screen, which comprises a display panel 3 comprising many pixels, wherein each pixel can emit any colour. The display panel 3 may be a TFT panel or an LCD panel having a conventional structure. A light source 1 is provided, which may, for example, comprise a backlight comprising a number of fluorescent tubes, LEDs or otherwise. LEDs are preferred for their fast switching.

In the arrangement shown, two polarising filters 2,4 are provided. The polarisers along with colour filters and alignment layers (not shown) will determine exactly how much light is allowed to pass through the display and which colours are created.

When no voltage is applied, the molecule structures of the display panel 3 are in their natural state and twisted by 90 degrees. The light emitted by the light source can then pass through the structure.

If a voltage is applied, i.e. an electric field is created, the liquid crystals of the panel 3 are twisted so that they are vertically aligned. The polarized light is then absorbed by the second and final polarizer 4 at the front of the display. Light can therefore not leave the display at this location.

The removal of the second polarising filter 4 (positioned in front of the display panel in the conventional flat panel display screen of Figure 1) forms the basis of this invention. Figure 2 shows a display panel suitable for use in embodiments of the present invention, in which the second polariser 4 at the front of the display is omitted.

Without any polarising panel in front of the display panel 3 for obstructing a user's direct view of the display panel 3, the flat panel display screen appears inactive to the naked eye, that is to say, with no final polarizer on the panel the screen appears blank. However, if the light source 1 is illuminated the light will leave the display.

Rendering the display (which does not feature a front diffuser) usable adjacent a primary display (such as a cinema screen) requires careful manipulation of the light emitted by the display, especially in a dark environment such as a cinema or theatre. Much work has been conducted by present inventor to arrive at a suitable arrangement that may be viewed by those interested in the information displayed on the screen, using a separate/personal polarising means, whilst limiting the emitted light to prevent the viewing experience of those not interested in the information displayed on the screen being unduly diminished.

Moreover, much work has been conducted by the present inventor to provide a screen with the front diffuser omitted that has sufficient resistance to damage, rendering it suitable for use in public environments or in consumer electronic devices and otherwise, without disrupting the desired polarisation of the display.

The unique features that suitably control the light emitted and maintain the integrity of the screen will become clear with the description that follows, along with further unique aspects of the different display systems presented herein in accordance with embodiments of the present invention.

Whilst the present invention is not limited to a specific form of remote polarising means for allowing the information displayed on the panel to be viewed, it is particularly preferred that the remote polarising means comprises a pair of lightweight glasses, such as those shown in Figure 2, which, unlike 3D stereoscopic polarized glasses where each eye is a polarizer at a different angle, have the same polarizing filter in each eye. Anyone not wearing the special polarized glasses just sees a blank display panel. Numerous alternative polarising means will be readily appreciated by those skilled in the art.

As an alternative to glasses, the remote polariser could, for example, be provided in the form of a polarized viewing window. This, like other cinema devices could be supported in a drinks holder on a stem. The arrangement could be such that flipping the viewing window over would allow viewing alternative systems, that are polarised at different orientations, such as screens A and B as shown in Figure 9.

An additional preferable feature of embodiments of the present invention is the provision of a further polarising filter (final polariser) forming part of the flat panel display screen, which is movably arranged such that in a first mode it may be positioned so that it does not obstruct a user's direct view of the display panel and in a second mode it may be positioned so that it obstructs a user's direct view of the display panel. Such an arrangement allows a flat panel display screen for use in the system, which may be converted between a closed caption arrangement, wherein the information displayed may only be seen by those wearing suitable glasses (or using a suitable polarised viewing means) and a normal viewing mode, wherein the information displayed may be viewed by any person without the need for glasses.

Such an arrangement may find particular use in public areas where the screens may have a dual function, showing public messages or information, including adverts and safety notices, as well as closed captions/discreet images at an appropriate time. Specific consideration is given to such arrangements below, with particular reference to Figures 24 to 26.

An alternative use for a display system in accordance with the principles of the present invention is as a privacy system, as shown in Figure 15, wherein a laptop 24 or other personal device, such as but not limited to smart phone or tablet computer, may be operated in a privacy mode, wherein the further polarising filter is moved from in front of the screen so that there is no image visible to the naked eye. A movable polarising filter may be provided, which is detachable from the device or movably attached thereto to slide or pivot from in front of the screen.

Any conventional form of polarising element for polarising the displayed image may be utilised in the embodiments of the present invention.

The polarisation may be linear. Conventionally flat panel monitors come as standard, where the rear polarizer is horizontal and the front polarizer is vertical. Whilst this is not a problem in the context of the present invention, it does not allow for much flexibility in relation to positioning the monitor in landscape or portrait modes. There may therefore be arrangements in accordance with the present invention where the orientation of the polariser is arranged diagonally at an angle of 45 or 135 degrees to the vertical, with the remote polariser/further polariser appropriately oriented at 90 degrees thereto. Such an arrangement is shown, for example in Figure 2. Here the polariser 2 is oriented at an angle of 45 degrees to the vertical and the polarizing lenses 4 of the glasses 5 are both oriented perpendicular to the orientation of the polariser 2.

The polarisation may alternatively be circular, with a circular polarizer instead of a linear polarizer in the monitor and/ or glasses. Circular polarizers are becoming more readily available, particularly in 3D cinema glasses, and have the advantage of allowing a greater degree of head tilting, when viewing the display of embodiments of the present invention.

Where a subtitling or signing wall is desired when the primary display comprises a 3D cinema screen, this would be possible by using 3D passive monitors as shown in FIG.16, instead of standard 2D monitors. The main difference between standard and 3D passive polarized monitors is that each horizontal line, representing a portion of the whole stereoscopic image, is polarized at opposing angles. In other words, the stereoscopic image is interlaced left and right creating a 3D image at half the vertical resolution. The final polarization filter usually found on a conventional monitor (linear vertical) is not used with 3D monitors and is instead replaced by an interleaved polarizer. This kind of polarizer is also known as "xpol" where each line is alternatively linear polarized at ninety degrees every line or circular polarized in opposite directions every line. Of course for 3D stereoscopic use, the polarization filter 27, must line up exactly with the display slices below 26 and corresponding 3D polarized glasses must be worn to see the 3D image.

However, where it is not desired to see a 3D images displayed on the 3D display screens, and it is preferred that only 2D alphanumeric subtitle data is sent to the display screens, the front xpol polarizer can be omitted as per the discussion above, and a blank screen will then be seen when viewed with the naked eye. When the 3D cinema circular polarized, glasses are worn, any image on the display will be seen, but also, the movie will be seen in 3D through the same glasses.

Text data can be segmentized and the signing video can be expanded by a video wall processor. 3D subtitles with a 3D movie, as desired, by carefully positioning text on the 3D monitors. A video wall processor may be used to allow a plurality of the flat panel display screens to be tiled together to make a bigger screen. For a subtitling screen running along the bottom of a cinema movie screen, for example, a row of several 22, 32 or 40-inch, or other sized flat panel display screens, may be provided that receive the subtitle text in one of several information formats through a wired or wireless (such as infra-red or Wi-Fi) link. This data will be synchronized with the movie via an xml file, or similar, and time code information so that the system may display text as and when subtitles are required. This row of monitors can just as well be a double row of 2 x 10 or some other variant able to show text at a reasonable size. Numerous screen configurations will be readily appreciated by those skilled in the art.

The text information could also come from a segment of the movie as image information or from text data expanded to fill the row (or rows) of monitors for subtitling. The subtitle row of monitors can each be in portrait configuration saving on the number of actual units required. The text data is preferably segmented, so, for example, only two characters appear on each flat panel display screen and the information is never displayed across any join where two monitors meet. Figure IB illustrates these principles by way of example only, wherein 4 screens are provided in a row. Conventional monitors and multimonitor stands can be used, while monitors can still have frames around them and displays can even have gaps between them.

Whatever the number or the configuration of the display screens used for the subtitling or the "signing wall", it is important to consider the relative orientation of the polarising filter in the display screen and the polarising filter(s) remote to the display screen/the movable further polarising filter, wherein the relative orientation should be at 90 degrees.

In addition to subtitle information, display screens according to the present invention may display signing information, which may comprise video of an individual hand signing. This may be displayed on a single screen or again may be segmented across multiple screens as discussed above using a video wall processing means.

In the case of a television transmission, part of the signal can contain subtitling text information or data, which is encoded and passed to a display screen or a row or cluster of display screens below or above the main TV screen. A portion of the signal may also contain signing video and be encoded and sent to a display screen or row or cluster of display screens. Alternatively a separate, and synchronized TV channel could contain all the information that is necessary for subtitles and signing, which is encoded and sent appropriately to the display screen(s) as appropriate. A control unit and software may be used for processing information for display on the flat panel display screens of the present invention, as will be readily appreciated by those skilled in the art.

The wearing of circular polarized glasses to view a 3D movie and also a special circular polarized interlaced subtitle display was discussed. In this instance the whole audience perceives the 3D movie and also the subtitles below the movie screen. However, if the subtitle display used linear polarization then viewers of the 3D movie would not see the subtitles which is the preferred solution. In this instance, viewers who wanted to see the 3D movie and also read subtitles would require a different type of viewing glasses referred to here as bi-focal subtitle glasses. Figures 17 to 21 show exemplarily how this may be achieved. A pair of 3D circular polarized glasses is split horizontally as in Figs.l7E and F, 18 and 19. The top half is circular polarized left and right respectively, while the bottom half is linearly polarized the same in each eye to view the subtitle display under the movie screen.

Fig.20 shows, schematically, how the viewer sees both the 3D movie and the subtitles through the bi-focal subtitle glasses.

In certain instances the linear polarizer required to view the subtitle display may be integrated and be part of the lens filter as shown in Fig 21 K or added to the front as an additional layer or even as a retro-fit filter for the customer to fit on to the glasses frame or even hinge up as required. In each instance the viewer wanting to see the 3D movie and also see the subtitle display will require the additional horizontal polarizer to view through. A conventional professional display monitor has most of the parts needed to produce a subtitle display including a long-life backlight and additional fan assisted cooling. However significant modifications are required to convert these monitors into reliable subtitle monitors. The differences are illustrated with reference to FIG. 22 & FIG. 23.

Firstly, the polarizer 42 of the conventional monitor of Figure 22 needs to be removed off the very front of the display screen. The removed polarizer is, in essence, replaced by a suitable remote polarising means, such as the lenses of the glasses as discussed herein, and/or by a further polarising filter that is slidably, hingedly or rollably or otherwise movably mounted to the monitor or is detachable from the monitor.

The present invention comprises a means for limiting the light emitted from the display panel, which means comprises at least one diffuser that is non-white in colour and is arranged to diffuse light emitted by the light source and a control means for automatically altering the brightness of the light source in dependence on a signal received from one or more ambient light sensors and/or cameras or in dependence on a predetermined light level of each scene of a video displayed on a secondary display that is provided adjacent the display panel.

With the means for limiting the light emitted from the display panel comprising one or more non-white diffusers, in front of the backlight LED array 37, the white diffuser panel 38 will be replaced with a dark Neutral Density panel 43. Also a further Neutral Density panel 44 may be placed just behind the LCD image panel 41 with the polarizer 40 affixed to it or otherwise provided in front of it. Whilst it is possible to place the further Neutral Density panel in front of the image panel, there is some risk of depolarizing the image panel, it is thus preferable that it is positioned behind the panel as shown in Figure 23. The Neutral Density panels may comprise tinted or dark coloured sheets. They may be black acrylic, in particular Perspex® 923 sheets. Additional or alternative panels may be used to the panels 43, 44. Each of the panels may reduce light by 3 stops.

With the means for limiting the light emitted from the display panel comprising a control means for automatically altering the brightness of the light source in addition to the use of the Neutral Density panels, the backlight illumination may be altered automatically in response to a signal received from one or more light sensors or cameras, or may be altered automatically in dependence on a predetermined light level of each scene of a film displayed on an adjacent cinema screen, wherein a suitable control arrangement will be provided in either case, as will be readily appreciated by those skilled in the art.

To strengthen the monitor once the front polariser 42 has been removed, it is useful to provide a front layer to replace the front polariser as a structural element (no such front layer is shown in Figure 23). It has been discovered that a layer of polyvinyl butyral is ideally suited to this task, since it does not disrupt polarisation. The layer of polyvinyl butyral may comprise a film layer that is adhered directly to the display panel. Most preferably, however, it is sandwiched between two glass sheets to form a self-contained panel that provides a front face of the monitor and acts as a structural member.

The monitor as described with respect to Figure 23, or any of the display panels in accordance with the present invention as described above, may be provided with a further polarising filter, such as any of those shown in Figures 24 to 26, which is arranged such that it may be selectively positioned in front of the monitor/display panel to render images displayed on the monitor/display screen visible without glasses or other remote polarising means. A particular use for such a further polariser would be where it was desirable to provide a screen usable in a discreet manner and additionally as a standard display screen for displaying information to all.

The further polarising filter will preferably cover the entire visible surface of the display panel in the standard viewing mode and will preferably be permanently attached to the monitor/flat panel display screen. The further polarising filter will preferably be powered to move between a position in which the screen is covered and a stowed position in which the screen is not covered. It could, however, be moved manually and could be detachable.

With reference to Figure 24, there is shown a further polariser that slides horizontally. A suitable frame may be provided within which the polariser is slideably mounted. With reference to Figure 25D, the screen could alternatively slide vertically. Clearly numerous alternative arrangements will be possible.

In Figures 25A to C there are shown alternative hinged arrangements, wherein movement of the screen occurs by rotation about an axis. Here the axes are all shown to be horizontal, they could alternatively be vertical.

In the arrangements of Figures 24 and 25, although not essential, the further polariser will generally be of rigid construction. With a flexible polariser used, which may comprise a thin sheet, further alternative arrangements are possible. One such arrangement is shown exemplarily in Figure 26, which is Tollable. In the depicted arrangement, a base is provided in which the roller is received, a scissor arm mechanism is used to raise and lower the further polariser. Of course alternative mechanisms may be used and the roller may be provided at the top of the display or may extend vertically rather than horizontally.

Reference list: 1 is the backlight; 2 is the first polarizer; 3 is the TFT Red, Green Blue pixel layer with Liquid Crystal within; 4 is the front/final polarizer; 5 is the movie screen; 6 is a subtitling wall; 6A is the main subtitle wall situated below the main movie screen; 6B is the secondary subtitle wall situated above the main movie screen; 7 is a signing wall; 7A is the main signing wall situated to the right of the main movie screen; 7B is the secondary singing wall situated to the left of the main movie screen; 8 is the movie projector; 9 is the film server; 10 is the subtitle the source for subtitle wall 6A; 11 is the signing source for signing wall 7B; 12 is the Subtitle Source for Subtitle Wall 6B; 13 is the Signing Source for Signing Wall 7A; 14,15,16 & 17 are the individual video wall or subtitle wall processors; 18 are Polarized glasses aligned to Subtitle Wall 6A and Signing Wall 7A; 19 are Polarized Glasses aligned to Subtitle Wall 6B and Signing Wall 7B; 20 are reversible polarized glasses as shown in FIGS.10,11 & 12;; 22 shows standard 22 inch monitors in a row, wherein each monitor shows just two characters; 23 are viewing glasses which have the same polarizer in each eye; 24 is a laptop with front polarizer removed where it is assumed that, as is the current convention, the rear polarizer (not shown) is horizontal while the front polarizer is vertical and the same as shown in the viewing glasses; 25 is a polarizing preserving 3D movie screen with standard Left & Right circular polarized projection images being received; 26 shows the alternate Left & Right images, line by line construction of a passive 3D display; 27 shows the front, alternate line (xpol) polarizer, having been removed from the display; 28 are standard circular polarized 3D cinema glasses; 28a are standard linear polarized 3D glasses with diagonal polarizer at 45 and 135 degrees, respectively; 29 are standard cinema circular polarized 3D glasses; 30 are subtitle viewing glasses for older monitors requiring diagonal polarization with the same filters in each eye; 31 are subtitle viewing glasses for newer monitors requiring horizontal polarization with the same filters in each eye; 32 are bi-focal, dual-purpose glasses for watching 3D movies and reading subtitles where the subtitle horizontal filters are overlaid in front of the circular filters; 33 are bi-focal, dual-purpose glasses for watching 3D movies and reading subtitles where the subtitle horizontal filters are split and separated from the circular filters; 34 are glasses frames; 35 is a circular polarizer; 36 is a horizontal polarizer; 37 is a case with an LED backlight array; 38 is a 6mm white diffuser; 39 is fresenal lens diffusers x 3; 40 is a vertical rear polarizer; 41 is an LCD picture panel; 42 is a horizontal front polarizer; 43 is a black Neutral Density diffuser (replacing a 6mm white diffuser); and 44 is a neutral density filter.

Claims

1. A display system comprising one or more flat panel display screens, and at least one remote polarising filter, which is remote to the one or more flat panel display screens, wherein the or each flat panel display screen comprises a display panel, a light source for illuminating the display panel, and a display panel polarising filter, which is arranged behind the display panel, wherein the flat panel display screen is arranged such that, in a first mode of operation, no polarising filter that forms part of the flat panel display screen is provided in front of the display panel to obstruct a user's direct view of the display panel, and wherein the display system comprises a means for limiting the light emitted from the display panel, which means comprises at least one diffuser that is non-white in colour and is arranged to diffuse light emitted by the light source and a control means for automatically altering the brightness of the light source in dependence on a signal received from one or more ambient light sensors and/or cameras or in dependence on a predetermined light level of each scene of a video displayed on a secondary display that is provided adjacent the display panel.

2. A display system as claimed in Claim 1, wherein the diffuser is tinted or a dark colour.

3. A display system as claimed in Claim 1, wherein the diffuser is black.

4. A display system as claimed in any of Claims 1 to 3, wherein the diffuser comprises an acrylic sheet.

5. A display system as claimed in any of Claims 1 to 4, wherein the diffuser comprises a neutral density filter.

6. A display system as claimed in any of Claims 1 to 5, wherein the flat panel display screen comprises one, two or more of the non-white diffusers that are arranged between the display panel and the light source, for limiting the intensity of light emitted by the flat panel display screen.

7. A display system as claimed in Claim 6, wherein two layers of 3 stop neutral density film are provided.

8. A display system as claimed in any preceding claim, wherein the light source comprises a plurality of light emitting diodes.

9. A display system as claimed in any preceding claim, wherein the flat panel display screen comprises a layer of polyvinyl butyral provided in front of the display panel.

10. A display system as claimed in Claim 9, wherein the layer of polyvinyl butyral comprises a film layer that is adhered directly to the display panel.

11. A display system as claimed in Claim 9 or 10, wherein the layer of polyvinyl butyral is sandwiched between two glass sheets to form a panel that provides a front face of the flat panel display screen.

12. A display system as claimed in any of Claims 9 to 11, wherein the layer of polyvinyl butyral covers substantially the entire front face of the display panel.

13. A display system as claimed in any preceding claim, wherein the flat panel display screen comprises a further display panel polarising filter, which is arranged such that it may be positioned in front of the display panel so as to provide a second mode of operation in which the further display panel polarising filter is provided in front of the display panel to obstruct a user's direct view of the display panel.

14. A display system as claimed in Claim 13, wherein the further display panel polarising filter covers the entire visible surface of the display panel in the second mode.

15. A display system as claimed in Claim 13 or 14, wherein the further display panel polarising filter is permanently attached to the flat panel display screen.

16. A display system as claimed in any of Claims 13 to 15, wherein the further display panel polarising filter is slidably, hingedly or rollably mounted to the flat panel display screen such that it may be moved between a first position in which it does not obstruct a user's direct view of the display panel and a second position in which it obstructs a user's direct view of the display panel.

17. A display system as claimed in any preceding claim, wherein the flat panel display screen comprises the screen of a personal electronic device.

18. A display system as claimed in Claim 17, wherein the personal electronic device comprises a personal computer, tablet computer or smart phone.

19. A display system as claimed in any preceding claim further comprising a cinema screen comprising the secondary display, wherein a plurality of the flat panel display screens are provided adjacent to the cinema screen.

20. A display system as claimed in Claim 19, wherein one or more of the plurality of flat panel display screens is arranged to display video images.

21. A display system as claimed in any preceding claim, wherein the display panel polarising filter is linearly or circularly polarised.

22. A display screen as claimed in any of Claims 1 to 19, wherein the display screen comprises a passive 3-D display screen.

23. A display system as claimed in any preceding claim, wherein the remote polarising filter comprises one or both lenses of a pair of glasses.

24. A display system as claimed in Claim 23, wherein both the lenses comprise the same direction polarizer as one another, which may be circular or linear.

25. A display system as claimed in Claim 23 or 24, wherein each lens is polarized diagonally and is rotatably mounted, such that the polarization direction of the glasses may be varied by ninety degrees by rotation of the lenses through 180 degrees.

26. A display system as claimed in any of Claims 23 to 25, wherein the lenses each comprise a first portion comprising the remote polarising filter and a second portion from which the remote polarising filter is omitted.

27. A display system as claimed in Claim 26, wherein the second portion is positioned above the first portion.

28. A display system as claimed in Claim 26 or 27, wherein the second portion of each lens from which the remote polarising filter is omitted comprises a circular polariser, and the flat panel display screen is arranged to display 3-D images.