GB2542416A - A 3D display and method of operation thereof - Google Patents

Abstract

An arrangement, method and device for a viewer 3 to visualize a 3D image by utilizing the Pulfrich Effect. The images are displayed on an arrangement of display surfaces, such as a first 1 second 2 and third display. The ratio of illumination entering the right and left eye is controlled to create a 3D effect as per the Pulfrich effect. Means for increasing the illumination, and the illumination ratio, may be in the form of at least one light source, such as a display screen, which may be placed in a monocular field of view, such as the peripheral vision of each of the left and right eye. The at least one light source may be an incandescent light source which may be positioned in proximity to the left and/or right eye. A louvre may be provided on the dorsum of the viewers nose.

Description

A 3D DISPLAY AND METHOD OF OPERATION THEREOF.

The present invention relates to a 3D display arrangement and a method of operation thereof, an optical device and a method of operating thereof, as well as software for carrying out such methods. The present invention also relates to moving pictures adapted for 3D image production. The images may be viewed in a cinema or at home for example.

Technical background

The Human Eye and Depth Perception

The human eye can sense and interpret electromagnetic radiation in the wavelengths of about 400 to 700 nanometers—visual light to the human eye. Many electronic instruments, such as camcorders, cell phone cameras, etc., are also able to sense and record electromagnetic radiation in the band of wavelengths 400-700 nanometer.

To facilitate vision, the human eye does considerable ‘image processing’ before the viewer “sees” the image.

When light ceases to stimulate the eyes photoreceptors, the photoreceptors continue to send signals, or ‘fire’ for a fraction of a second afterwards. This is called ‘persistence of vision’, and is key to the invention of motion pictures that allows humans to perceive rapidly changing and flickering individual images as a continuous moving image.

The photoreceptors of the human eye do not ‘fire’ instantaneously. Under low light conditions can signals can take a few thousands of a second longer to transmit than under brighter conditions. Causing less light to be received in one eye than another eye, thus causing the photoreceptors of the right and left eyes to transmit their ‘pictures’ at slightly different times, explains in part what is known as the Pulfrich 3-D vision illusion.

Once signals are sent to the eyes, the brain processes the dual images together (images received from the left and right eye) presenting the world to the mind in 3-dimensions or with ‘DepthPerception’.

Stereopsis is a term that refers to the perception of depth and 3-dimensional structure obtained on the basis of visual information deriving from two eyes by individuals with normally developed binocular vision. Because the eyes of humans, and many animals, are facing forward and located at different lateral positions on the head, binocular vision results in two slightly different images projected onto the retinas of the eyes. The differences are mainly in the relative horizontal position of objects in the two images. These positional differences are referred to as horizontal disparities or, more generally, binocular disparities. Disparities are processed in the visual cortex of the brain to yield depth perception. While binocular disparities are naturally present when viewing a real 3-dimensional scene with two eyes, they can also be simulated by artificially presenting two different images separately to each eye by stereoscopy. The perception of depth in such cases is also referred to as "stereoscopic depth".

The perception of depth and 3-dimensional structure is, however, possible with information visible from one eye alone, such as differences in object size and motion parallax (differences in the image of an object over time with observer movement), though the impression of depth in these cases is often not as vivid as that obtained from binocular disparities. Therefore, the term stereopsis (or stereoscopic depth) can also refer specifically to the unique impression of depth associated with binocular vision; what is colloquially referred to as seeing "in 3D".

There are two distinct aspects to stereopsis: coarse stereopsis and fine stereopsis, and these provide depth information of different degree of spatial and temporal precision. Coarse stereopsis (also called gross stereopsis) appears to be used to judge stereoscopic motion in the periphery. It provides the sense of being immersed in one's surroundings and is therefore sometimes also referred to as qualitative stereopsis. Coarse stereopsis is important for orientation in space while moving, for example when descending a flight of stairs.

Fine stereopsis is mainly based on static differences. It allows the individual to determine the depth of objects in the central visual area (Panum's fusional area) and is therefore also called quantitative stereopsis. Fine stereopsis is important for fine-motor tasks such as threading a needle.

The stereopsis which an individual can achieve is limited by the level of visual acuity of the poorer eye. In particular, patients who have comparatively lower visual acuity tend to need relatively larger spatial frequencies to be present in the input images, else they cannot achieve stereopsis. Fine stereopsis requires both eyes to have a good visual acuity in order to detect small spatial differences.

Perspective uses information that if two objects are the same size, but one object is closer to the viewer than the other object, then the closer object will appear larger. The brain processes this information to provide clues that are interpreted as perceived depth.

Motion parallax is the effect that the further objects are away from us, the slower they move across our field of vision. The brain processes motion parallax information to provide clues that are interpreted as perceived depth.

Shadows provide another clue to the human brain, which can be perceived as depth. Shading objects, to create the illusions of shadows and thus depth, is widely used in illustration to imply depth without actually penetrating (perceptually) the 2-D screen surface.

Methods of Producing 3-D Illusion in Moving Pictures

Motion pictures have traditionally been images in 2-dimensions. However, several methods have been developed for providing the illusion of depth in motion pictures. These include the Anaglyph, IMAX (Polaroid), autostereoscopy and Pulfrich 3-dimensional illusions.

Solutions were implemented to allow the anaglyphic methods to be implemented with a single projector.

These methods all require filters placed between the eyes of the viewer and the screen on which the Moving Pictures are displayed.

These filters are usually mounted on glasses that the viewer wears while watching the moving pictures. Examples of such glasses are given in US8941919B2 Continuous adjustable 3D filter spectacles for optimized 3Deeps stereoscopic viewing, control method and means therefor, and system and method of generating and displaying a modified video, US20100066813 STEREO PROJECTION WITH INTERFERENCE FILTERS, US8947512B1 User wearable viewing devices.

In single projector settings; the use of filters leads to a reduced brightness perceived by the viewers.

Autostereoscopy refers to the representation of stereoscopic images without the use of glasses, also referred to as glassless or glass free 3D, for rendering the three-dimensional effect, using a combination of both stereo parallax and movement parallax. To implement it on a flat panel display, parallax barriers or lenticular lenses are used in combination with the flat panel. However, it leads to a reduced image resolution and only works for certain positions of the user with respect to the display. A different image is seen through each eye, therefore rendering the three dimensional illusion. Autosteroscopy is mainly used for scientific and medical 3D visualisation, and computer games or advertising. However, autostereoscopy has no application in cinema due to the required positions by the viewer.

An immersive theater is described in US 5,963,247 “Visual display systems and a system for producing recordings for visualization thereon and methods therefor”. A central screen is flanked by a first screen on its left and a second screen on its right thereby immersing the viewers in the theatrical experience as illustrated in figure 7.

In such an immersive theater, the glasses used for 3D performances can obstruct at least part of the lateral field of view or create a discontinuity that can reduce the comfort of the experience of the viewers.

The Pulfrich effect is generally induced by placing a dark filter over one eye. The phenomenon is named after the German physicist Carl Pulfrich, who first described it in 1922. The effect has been exploited as the basis for some television, film, and game 3D presentations.

If a camera starts at position X and moves right to position Y, and a viewer watches this segment with a dark lens over the left eye, then when the right eye sees the image recorded when the camera is at Y, the effect of the lower light intensity entering the left eye means that the left eye will react a few milliseconds behind the right eye. This means that the image seen by the left eye will be of an image recorded at X, thus creating the necessary parallax to generate right and left eye views and 3D perception, much the same as when still pictures are generated by shifting a single camera. One advantage of this system is that people not wearing the glasses will see a perfectly normal picture.

Barco Escape™ makes use of three large screens at the front and to the left and right in a cinema. Such screens produce not a narrow beam of light and it can be expected that a distributed light is generated that can be seen by the eye closest to the screen not only in peripheral vision but perhaps also in the central visual area. Also the image projected is a video image and not a static light. One can expect that some light can even enter the eye furthest away from the side screen.

It has not been mentioned that the Pulfrich effect will take place when three such screens are used.

It has been reported that one can use a low intensity light source, such as a flashlight, to add light to one eye rather than filtering one eye to induce the Pulfricht effect. Using a flash light puts a narrow beam of light into one eye.

The use of filters is therefore not required. The art remains nevertheless silent on how the flashlight should be positioned in order (a) not to obstruct the field of view and (b) to illuminate a single eye of each viewer. Also, such a flashlight tends to dazzle the viewer.

There is room for improvement in the art.

Summary of the invention. A first object of embodiments of the present invention is to provide systems and devices for moving pictures with some 3D effect, a method and an arrangement for producing moving pictures with some level of three dimensional effect when viewed by at least some viewers. An advantage of some embodiments of the present invention is that such images can be seen in 3D without wearing glasses, or any other device.

Embodiments of the present invention solve the problem caused by generating 3D images with the viewer wearing glasses, and therefore embodiments of the present invention can provide 3D images without discontinuities in the field of view of the viewer. This can be achieved by providing an arrangement of a first, second and third display surfaces on which moving images are to be displayed for viewing by a viewer with a left and a right eye, the third display surface being positioned in front of the viewer, the first display surface being positioned so that the viewer has the first display surface on the right side, the second display surface being positioned so that the viewer has the second display surface on the left side; a first means is provided for increasing a first ratio of an illumination entering the right eye of the viewer compared to the illumination entering the left eye (optionally without reducing the illumination entering the left eye) dependent upon horizontal movement of an object on the third display surface, (optionally, when at least one object in images on the third display surface is moving generally in a horizontal direction from right to left as understood by the viewer or vice versa), and a second means for increasing a second ratio of an illumination entering the left eye of the viewer compared to the illumination entering the right eye (optionally while not decreasing the illumination entering the right eye) dependent upon horizontal movement of an object on the third display surface (optionally when at least one object in images on the third display surface is moving generally in a horizontal direction from left to right as understood by the viewer or vice versa), so as to create 3D images according to the Pulfrich effect.

Which of the first and second means for increasing the first and second ratio are employed depends on whether the object with the horizontal movement is to be pushed back and should appear further away from the viewer or whether the object should appear closer to the viewer. The first and second means for increasing the first and second ratio comprise at least one light source. A control unit is provided for switching between the first and second ratios. It is preferred if the switching is done with a ramp up the signal so that the change is not sudden in preparation of a 3D scene.

The first and/or second ratio is preferably five or more, more preferable 9 or more.

Such an arrangement of display surfaces can provide an advantage of generating 3D effects without the use of glasses. The present invention does not exclude the possibility of using dedicated head gear.

The present invention does not exclude the possibility that some viewers are unable to see the 3D effect. Such viewers, who are not sensitive to three dimensional effects, will experience the motion picture as usual. This is a significant improvement over conventional stereoscopic three dimensional moving pictures which are viewed with glasses which stereoscopic three dimensional movies superpose two images, and which therefore cannot be viewed without wearing the correct glasses.

In a preferred embodiment, the first and second means for increasing the first and second ratio are controlled by a control unit which receives command signals correlated to the displayed images of the at least one motion picture according to the horizontal moving direction of the at least one object.

This provides the advantage that the illumination of the eyes is automatically controlled and can react fast to any movement occurring in the motion picture.

Preferably, said command signals are not detectable by the viewer, i.e. are invisible to the viewer. Such command signals can be transmitted by at least one of infrared light, or radio frequency wavelengths of light, ultrasound, etc. (including Bluetooth, wifi, ... 3G, 4G, ...)

Such signals provide wireless solutions although the present invention includes in embodiments wired solutions as well, or a combination of both.

For example, in another preferred embodiment, said command signals are transmitted with at least one of ultrasonic sound, or infrasonic sound. The signals can be therefore provided to the first and second means for increasing the first and second ratios i through the soundtrack of the motion picture, without disturbing the viewer as these are not audible.

It is another aspect of the current invention to provide first and second means for increasing the first and second ratios further comprise at least one light source positioned in a monocular field of view of each of, respectively, the left and right eye. When the light source is positioned in a monocular field of view, it provides the advantage that the first means for increasing the illumination does not disturb the left eye and the second means for increasing the illumination does not disturb the right eye.

In another preferred embodiment, the at least one light source is a display surface, e.g. one of the display surfaces used in a cinema or in a home theatre setting for display of moving pictures. An advantage is that no additional light source is required and a Barco Escape™ cinema setting can be used to create 3D displays. No further hardware is required.

The first and second means for increasing the first and second ratios may be, for example, a louver to be positioned on the dorsum of the viewer’s nose. An advantage is that such a louver blocks stray light and blocks light generated in the monocular field of view of each eye to penetrate the opposite eye.

In another embodiment, at least one light source is an incandescent source, or a solid state light source.

In another preferred embodiment, the at least one light source is one or more LEDs.

In another embodiment, said light source, e.g. comprising at least one LED, emits at least one of white, red, green, blue light or any combination thereof. An advantage is that light sources, e.g. LEDs of different colors can be light up according to the content and color content of the displayed motion picture.

Preferably, the at least one light source is positioned in a proximity of respectively the left and right eye.

Advantageously, the at least one light source is positioned adjacent to the lateral cantus, at the level of or below the lateral hooding area of the eye, or at the level of or below the lower eyelid or close to the medial canthus.

In a preferred embodiment, at least one of the display surfaces is a front projection screen. An advantage is that any traditional cinema can be used to provide such an arrangement of display screens.

Preferably, the display surfaces for displaying moving pictures comprise at least one of an LCD, an LED, a projection screen, an LED wall, a CRT or a plasma fixed format display.

In another preferred embodiment, wherein at least one of the display surfaces is a back projection screen. Back projection screens provide the advantage to be compact and easy to install. Such back projection screens can be used for instance for the lateral screens of the Barco Escape™ system, and allow to upgrade a classical cinema to a three screen

Barco Escape™ set up and to provide a 3D image display.

Preferably, the back projection screen comprises multiple back projectors. The advantage of using multiple back projectors is to increase the size of the side screens. One projector is not enough to provide a side screen, whose size is comparable to that of a front projection cinema screen.

Most preferably, to reduce the depth of the side screens use multiple back projection units with a plurality of blended images.

Optionally, the back projection screens are set up for temporary use.

Advantageously, the arrangement is installed within a cinema, a theatre, an opera, a conference room, a concert hall, in a room or an outdoor cinema at night. A second object of embodiments of the present invention is to provide a device for assisting the visualization of some three dimensional effects in moving pictures without disturbing the field of view and without dazzling the viewer.

Embodiments of the present invention also provide a device for viewing three-dimensional effects in at least one motion picture displayed on at least one display surface, the device comprising first means for increasing a ratio of an illumination entering the right eye of a viewer compared to an illumination entering the left eye (optionally without reducing the illumination entering the left eye) dependent upon a horizontal movement of an object on the third display surface (optionally when at least one object in images displayed on the third display surface is moving generally in a horizontal direction from right to left from the viewer’s point of view, or vice versa), second means for increasing a ratio of an illumination entering the left eye of the viewer compared to an illumination entering the right eye (optionally, without reducing the illumination entering the right eye) dependent upon horizontal movement of an object on the third display surface, (optionally when at least one object in images displayed on the third display surface is moving generally in a horizontal direction from left to right from the viewer’s point of view, or vice versa), and a control unit for switching between the first and second ratio so as to create 3D images according to the Pulfrich effect. It is preferred if the switching is done with a ramp up of the signal so that the change is not sudden in preparation of a 3D scene.

Which of the first and second means for increasing the first and second ratio are employed depends on whether the object with the horizontal movement is to be pushed back and should appear further away from the viewer or whether the object should appear closer to the viewer.

The first and second means for increasing the first and second ratio comprise at least one light source.

An advantage associated with the device according to these embodiments of the present invention is that the user may move his head without influencing the three dimensional effects created.

In a preferred embodiment, the command signals are invisible light signals such as infrared signals, and the control unit comprises therefore an infrared detector.

In another embodiment, the command signals are signals at radio frequency wavelengths such as provided by Wifi, Bluetooth, 3G, 4G, etc.

In another embodiment, the command signals are sonic signals that cannot be detected by humans such as ultrasonic or infrasonic sound and can be emitted in parallel to the audio soundtrack of the moving pictures. However, the viewer doesn’t hear the command signals. In this embodiment, the control unit comprises an ultrasound or infrasound detector accordingly.

In a preferred embodiment, the first and second means for increasing the first and second ratio are to be positioned in a monocular field of view of the left and/or right eye such that the means for increasing the illumination of the left eye do not disturb the right eye and inversely.

It is an advantage of this further aspect of the invention that the device does not interfere with the field of view of the binocular vision, which increases strongly the comfort and the image quality provided by the device.

In a another aspect of the invention, an apparatus to induce the Pulfrich effect comprises at least one source of light with a light exit and a support structure to maintain the source of light in a position relative to the head of a viewer; wherein the light exit of the source of light is positioned close to one eye of the viewer so as to illuminate said one eye.

It is an advantage of this aspect of the invention that the Pulfrich effect can be induced at will regardless of the position of the head of the viewer.

In a further aspect of the invention, the light exit is positioned adjacent to the lateral cantus of the at least one eye and at the level of or below the lateral hooding area of that eye.

It is an advantage of this aspect of the invention that it will disturb the viewer as little as possible while allowing an adequate illumination of the eye on the same side of the head as the light exit. It is a further advantage of this aspect of the invention that when the light exiting the light exit has a color similar to a color of the visual environment of the viewer, the disturbance to the viewer will be even more reduced.

Alternatively, the light exit is positioned at the level of or below the lower eyelid. Alternatively, the light exit is positioned close to the medial canthus.

In all cases, it is an advantage if the position of the light exit is such that it is blocked by the root and dorsum of the nose and does not reach the other eye.

In another aspect of the invention, the support structure also maintains a louver close to the root and/or dorsum of the nose to shield each eye of the viewer from stray light. The louver shields thus the left eye from light coming from the right of the viewer and the louver shields the right eye from light coming from the left side of the viewer.

It is an advantage of this aspect of the invention that by reducing the amount of stray light reaching the other eye, the Pulfrich effect will be more pronounced.

In a further aspect of the invention, the apparatus comprises a receiver to receive command signals and control electronics to activate the source of light and illuminate the corresponding eye of the viewer at a well determined moment e.g. in order the induce the Pulfrich effect at one or more time during a motion picture.

In a further aspect, a mobile phone is used to receive the command signals and control the activation of the at least one source of light.

In a further aspect of the invention, the apparatus has a source of light with a light exit for each eye of the viewer.

In a further aspect of the invention, the apparatus is used in conjunction with a Barco Escape™ projection system.

When used with a Barco Escape™ projection system, the light source collects light emitted by one of the lateral screens. The light can be collected by a light funnel, whether hollow or full. The advantage of that aspect of the invention is that the apparatus does not have to be powered. Furthermore, no electronics is required to activate the light source at the opportune moment when the viewer looks at a motion picture. A reflecting surface fastened to the support structure of the apparatus can be positioned adjacent to the root and dorsum of the nose to reflect light into the eye. The reflecting surface can be used alone or in conjunction with a light funnel. The reflecting surface can be an integral part of a louver on the dorsum of the nose of the viewer.

Alternatively, the apparatus is powered and command signals are transmitted by light projected on the lateral screens. (For instance: right left light imbalance + photosensor).

The light projected can be infra-red light projected by one of the projectors or by a dedicated infra-red projector. In a further aspect of the invention, the apparatus is used in conjunction with an emissive display.

In a further aspect of the invention, the apparatus is used for phototherapy. An advantage of the apparatus according to this invention is that it allows the person wearing the apparatus to carry on with normal activity instead of being immobilized for 30 minutes or more a day as is the case with the existing “light boxes” used to treat seasonal affective disorder, (http://www.psfk.com/2014/05/light-therapy-glasses.html)

The present invention also includes a sensor to evaluate dark adaptation / light adaptation locally.

In accordance with another aspect, when used with a Barco Escape™ projection system, a light source on a head mounted device collects light emitted by one of the lateral screens. The light can be collected by a light funnel, whether hollow or full. The advantage of that aspect of the invention is that the apparatus does not have to be powered. Furthermore, no electronics is required to activate the light source at the opportune moment when the viewer looks at a motion picture. A reflecting surface fastened to the support structure of the apparatus can be positioned adjacent to the root and dorsum of the nose to reflect light into the eye. The reflecting surface can be used alone or in conjunction with a light funnel. The reflecting surface can be an integral part of a louver on the dorsum of the nose of the viewer.

Alternatively, the head mounted device is powered and command signals are transmitted by light projected on the lateral screens. (For instance: right left light imbalance + photosensor). The light projected can be infra red light projected by one of the projectors or by a dedicated infra red projector. In a further aspect of the invention, the device is used in conjunction with an emissive display.

In a further aspect of the invention, the apparatus is used for phototherapy. An advantage of the apparatus according to this invention is that it allows the person wearing the apparatus to carry on with normal activity instead of being immobilized for 30 minutes or more a day as is the case with the existing “light boxes” used to treat seasonal affective disorder.

Brief description of the figures.

Figurel is an arrangement of a main projection screen and a lateral projection screen for use with embodiments of the present invention.

Figure 2 is schematic top view of an arrangement of two screens for use with embodiments of the present invention, indicating the orientation and the distances of the screens and a main viewer.

Figure 3 is a main screen displaying a motion picture of a merry go round

Figure 4 shows a louver according to an embodiment of the present invention.

Figure 5 shows a louver according to an embodiment of the present invention worn by a viewer.

Figure 6 is a device for viewing three dimensional effects according to an embodiment of the present invention

Figure 7 is a schematic representation of a front projection display comprising three front projection screens and three projectors for use with embodiments of the present invention

Figure 8 is schematic representation of three positions (a) adjacent to the lateral cantus and at the level of or below the lateral hooding area of that eye (b) at the level of or below the lower eyelid and (c) close to the medial canthus according to embodiments of the present invention.

Figure 9 illustrates a headset according to an embodiment of the present invention.

Figure 10 is a schematic representation of a viewer wearing the headset of figure 9

Figure 11 is a schematic representation of a cavity wherein a plurality of LEDs are fixed according to an embodiment of the present invention.

Figure 12 is a schematic layout of a circuit according to an embodiment of the present invention

Figure 13 is a schematic representation of a viewer in a Barco Escape™ setting, with one projector, two lateral displays and a main screen for use with embodiments of the present invention.

Figure 14 is a checkerboard pattern image wherein the pads are black and white.

Figure 15 is the negative of the checkerboard pattern image of figure 14.

Figure 16 is an image of alternating narrow black and white stripes.

Figure 17 is the negative image of figure 16.

Figure 18 is an image of alternating wide black and white stripes.

Figure 19 is the negative image of figure 18.

Figure 20 is an image which is half black and half white.

Figure 21 is the negative image of figure 20.

Figure 22 is a black image,

Figure 23 is a white image, the negative of figure 22.

Definitions “Motion picture”. 1. A sequence of filmed images viewed in rapid succession so that the illusion of continuity and motion is created. 2. The complete thematically related content of such images. Also known as cinema; movie; moving picture, (according to McGraw-Hill Dictionary of Scientific and Technical terms, Sixth Edition. )

Throughout the description, the following terms relate to display surfaces: display, front projector display, display surface, display screen, lateral display, display surface, front projection screen. However, lateral refers to screens positioned laterally with respect to a viewer and front or main refers to a screen positioned in front of a viewer. A “display screen” can be a projection screen, a LCD screen, an LED screen, a plasma screen, or any other fixed format display.

Barco Escape™ is an arrangement of three display surfaces one immediately in front of a viewer and one on each side. Projectors are provided for projecting motion pictures onto the three display surfaces. The display surfaces may also be emitting screens such as LED walls.

Detailed description of embodiments.

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

Moreover, the terms top, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions unless it is specifically stated as such. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

First embodiment

It is a first aspect of the present invention to provide a method, an arrangement, and/or devices with first, second and third display surfaces on which moving images are to be displayed for viewing by a viewer with a left and a right eye, the third display surface being positioned in front of the viewer, the first display surface being positioned so that the viewer has the first display surface on a right side, the second display surface being positioned so that the viewer has the second display surface on a left side; a first means for increasing a first ratio of an illumination entering the right eye of the viewer compared to an illumination entering the left eye (optionally without reducing the illumination entering the left eye) dependent upon horizontal movement in the images on the third display surface (optionally when at least one object in images on the third display surface is moving generally in a horizontal direction from right to left or vice versa), and a second means for increasing a second ratio of an illumination entering the left eye of the viewer compared to an illumination entering the right eye (optionally, while not decreasing the illumination entering the right eye) dependent upon horizontal movement in images on the third display surface (optionally when at least one object in images on the third display surface is moving generally in a horizontal direction from left to right or vice versa), and a control unit for switching between the first and second ratio so as to create 3D images according to the Pulfrich effect.

The control unit controls the light output from the display surfaces. The lateral screens are controlled to change the amount of light entering the eye closest to the relevant lateral screen, and this will control the generation of the Pullfrich 3D experience.

Which of the first and second means for increasing the first and second ratio are employed depends on whether the object with the horizontal movement is to be pushed back and should appear further away from the viewer or whether the object should appear closer to the viewer. Pulfrich effect is not limited to having the image perceived in front of the screen but also behind the screen (i.e. creates depth), for a given illumination ratio, an object moving left to right will appear in front of the screen while an object moving right to left will appear deeper into / behind the screen. The same ratios / illumination on left and right may have a desirable effect depending on what one wants to achieve (object in front, object behind an even the two at the same time: one object moving in one direction will appear in front while an object moving in the other direction will appear behind).

Such an arrangement of display surfaces can provide a 3D display without glasses, i.e. can provide an autostereoscopic viewing experience. The first and/or second ratio is preferably five or more, more preferably 9 or more. It is preferred if the switching is done with a ramp up of the signal so that the change is not sudden in preparation of a 3D scene.

The embodiment provides a method to induce the Pulfrich effect using at least a first display and a second display; the first display illuminating both the left and right eye of a viewer and the second screen being (predominantly) in the monocular field of view of the right eye or the left eye in order to illuminate one eye more than the other ....

For example the ratio can be generated by the central display in combination with light from one lateral display on the left of the viewer displaying darker images than the images on the central display in combination with light from the lateral display on the right of the viewer which must display a brighter image than the image displayed on the central display 1 and the display on the left of the viewer. The intensity of the light illuminating the retina of the left eye (to which light emitted by the display on the left of the viewer and light emitted by the central screen contributes) will be less than the intensity of the light illuminating the retina of the right eye (to which light emitted by the display on the left of the viewer and light emitted by the central screen contributes).

This first aspect will be illustrated by the embodiment shown in figures 1 and 2. The 3D display according to the invention comprises at least two display surfaces, in the current example LCD displays. A first display 1 and a second display 2. A third display surface (given the reference number 6), or LCD display can be positioned on the left side as well but has been omitted for the sake of simplifying the description. A viewer 3 faces the first display 1 at a distance D1 as seen on figure 2. A second display 2 makes an angle (a) with the first display 1. In this example, the second display 2 is on the right side of the viewer 3 as indicated on figure 2.

The second display 2 is at a distance D2 from the first display 1, the distance D2 is measured as indicated on figure 2. The second display can also be shifted closer to the viewer; this shift is characterized by the distance D3 as indicated on figure 2.

The angle β is the angle beyond which objects on the right side will disappear from the monocular field of view of the left eye. The angle β is the angle beyond which objects on the right side will disappear from the monocular field of view of the left eye. The angle β may vary from individual to individual. For the test subjects who evaluated the display, β was in the interval 15 to 30 degrees. The angle β may vary from individual to individual and from the position of the viewer. While not necessary, it may be advantageous to position the viewer with respect to the second display 2 so that it will be outside of the (left) monocular field of view of viewer 3 in order not to illuminate the left eye directly (i.e. ray of lights emitted by the second display 2 do not reach the left eye in a straight line).

Means for increasing the illumination entering one eye of the viewer is, in the current example, provided by display 2 itself.

The average luminance of display 1 was modified in three ways: - By varying the image content (e.g. an entirely black image is less bright than an entirely white image) that determines the state in which the spatial light modulator is. - By varying the luminance of the backlight (on most laptop computers, the brightness can be increased or decreased by using keyboard shortcut like e.g. Fn [ or Fn | on a DELL Latitude E6420). - By adding a filter covering part or whole of the screen.

Display 1 was the screen of a DELL LATITUDE E6420 with a diagonal of 14 inches (the active display area being 310 mm X 175 mm), a 16:9 aspect ratio and a maximum average luminance of +/- 277 cd/m2.

Display 2 was an Acer AL718 with a diagonal of 17 inches (the active display area being 340 mm X 270 mm) and a maximum average luminance of +/- 200 cd/ m .

The moving pictures used on display 1 to evaluate the Pulfrich effect were those of a merry-go-round (also known as carousel): the merry-go-round is seen from a lateral view (as seen on figure 3) and rotates at an apparent angular speed ω of Π/2 s'1 (or 90 degrees of angle per second) which amounts to say that the moving pictures have a period T of 4 s. The direction of the movement in the plane of display 1 is from the right to the left from the viewer’s perspective, the maximum amplitude A of the apparent movement in the plane of display 1 being 200 mm (that is, the position of given point of the image of the merry-go-round will vary between two extremes El and E2 on the screen of display 1, the maximum difference A between these two extremes for an outermost point of the merry-go-round being 200 mm or 2/3 of the width of the active display area). In the example of figure Y, El and E2 corresponds to the tip of the left wing of an airplaneshaped nacelle 4.

The tests were carried-out in a closed room approximately 7 m X 5 m and 2.5 meter high. The only light sources during the test were the screens of display 1 and display 2 to emulate the situation in a cinema. The closest wall on the left side of the viewer was at approximately 2 meters from the viewer. The closest wall behind the viewer was at approximately 1.5 meters from the viewer.

The table on which display 1 and 2 stood was covered by a dark, matte tablecloth to limit reflection of light from display 2 onto the left eye of the viewer.

Tests were carried out with different configurations. In a first configuration, D1 = 1 m, D2 = 0 m, D3 = 0 m and a = 155 degrees of angle. In a second configuration, D1 = 0.8 m (“.” Is used as decimal separator e.g. 0.1 is one tenth), D2 = 0.1, D3 = 0.3 m and a = 120 degrees of angle. In a third configuration D1 = 0.6 m, D2 = 0.2, D3 = 0.4 m and a = 100 degrees.

The contrast setting of display 1 was left at factory settings.

The image displayed on display 2 during the tests were a white field (i.e. entire image is white), a black field (i.e. entire image is black), a light gray field and a dark gray field. The luminance of display 2 for these 4 images was evaluated: a white field corresponded to an average luminance of approximately 200 cd/m , a black field corresponded to an average luminance of less than 5 cd/m , a light gray field corresponded to an average luminance of approximately 75 cd/m and a dark gray field corresponded to an average 2 luminance of approximately 50 cd/m .

The luminance of display 1 was evaluated on randomly selected still images in the moving pictures used to evaluate the Pulfrich effect. With a first filter positioned on the entire screen, the average luminance of the screen of display 1 appeared to be approximately 10 cd/m2. With a second filter (superposed to the first), the luminance of the screen appeared to be less than 1 cd/ m .

There was no systematic dark adaptation before the tests. A 200W halogen lamp was used between tests on the different configurations to allow the configuration to be changed.

In spite of reflection of the light emitted by Display 2 on the walls, the viewer, the desk and reaching the left eye and cross talk between display 2 and display 1 (i.e. light emitted by display 2 impinged on display 1 either directly or by reflection on walls, desk and viewer), the Pulfrich effected was perceived when the luminance of the light from display 2 entering one eye was 10 times higher or lower than the luminance of the light entering the other eye from display 1 and this for all configurations (in the first configuration, part of display 2 was still in the monocular field of view of the left eye and a louver positioned on the dorsum of the viewer’s nose was used to prevent light emitted by display 2 from reaching the left eye in a straight line. The right eye being illuminated and the apparent motion of the nacelles on the screen of display 1 being directed from the right to the left, the nacelles (see figure 3) appeared in 3D, i.e. came out of the screen on the right and to re-enter on the screen on the left. This was in agreement with the Pulfrich effect as described in e.gTHE MAGNITUDE OF THE PULFRICH STEREOPHENOMENON AS A FUNCTION OF BINOCULAR DIFFERENCES OF INTENSITY AT VARIOUS LEVELS OF ILLUMINATION” by Albert Lit in the American Journal of Psychology volume LXIINo. 2 of April 1949 pages 159 to 181; ’’Pulfrich autostereo display with micro-prism array” by Chien-Yue Chen et al and others who studied the effect.

The impression of a three dimensional merry-go-round disappeared when display 2 was turned off and re-appeared when display 2 was turned on again. Whether or not the effect disappeared or reappeared gradually was not evaluated. The test subject mentioned nevertheless that the effect seemed to persist for a brief instant after display 2 was turned off.

In a cinema of home theater setting with three screens, the ratio of illuminations that enter one eye includes the ratio of the light from images on a first display surface 1 directly in front of the viewer combined with light from a lateral display surface 6 and any ambient light compared with the light entering the other eye from the first display surface 1 combined with light from the other lateral display surface 2 and any ambient light entering the other eye. This ration should preferably be greater than 5, and more preferably greater than 9. The director of the film can select scenes that achieve this ratio.

The perception of the effect was sensibly improved in all configurations when a louver 5 was positioned on the dorsum of the viewer’s nose (see figure 4 and figure 5). The louver 5 further limits the amount of light emitted by a lateral display which is incident on the opposite eye while having no or little impact (e.g. by reflection) on the eye on the same side of the head as the lateral screen in question. In other words, the louver 5 further limits the amount of light emitted by the display surface or screen on the right of the viewer and that would illuminate the left eye of the viewer, this also applies to stray light reflected by surfaces on the right side of the viewer. A configuration with three display surfaces such as three fixed format such as LED or LCD or Plasma displays allows the Pulfrich effect to be induced “symmetrically” for both directions of horizontal motion on the central display surface or screen 1. With symmetrically, it is meant that it will be possible to let an object be perceived either in front of the display (that is closer to the viewer than the display is) or behind the display (that is farther from the viewer than the display) regardless of its perceived direction of motion: left to right or right to left. If the perceived motion on the central screen 1 goes from the right to the left, the display 6 on the left of the viewer in combination with light from the central display and any ambient light must display dark or darkened images (in order to decrease their luminance and as a result to decrease the intensity of the light illuminating the retina of the left eye) and the light from the display surface 2 on the right of the viewer in combination with the light from the first display surface 1 and any ambient light must display a bright image (in order to increase the luminance and as a result to increase the intensity of the light illuminating the retina of the right eye). The ratio of light intensities should be 5 or greater or more preferably 10 or greater. In this case, the object or objects in motion (from the right to the left) on display surface 1 will appear to be in front of the display 1, closer to the viewer 3 than display 1. If it is display 2 that displays a dark image while display 4 displays a bright image (brighter than the image on the screen of display 1 and display 2), the objects moving from right to left on the screen of display 1 will appear to be behind display 1, farther away from viewer 3 than display 1.

As was described earlier, a louver positioned on the nose of viewer 3 can improve the perception of the Pulfrich effect. This is certainly the case when the display 2 on the right of viewer 3 is within the monocular field of view of the left eye of viewer 3 and/or when the display 5 on the left of viewer 3 is within the monocular field of view of the right eye of viewer 3.

Alternatively, one can draw the attention of the viewer to one of the lateral screens while displaying dark moving images on that lateral screen and displaying bright images (moving or not) on the central display (or the central and/or the other lateral display). Depending on the apparent motion on the lateral screen, the moving object will appear to emerge from the lateral display (in other the words the moving object will appear to be in front of the plane of the screen of the display) or it will appear to be behind the plane of the screen of the display.

In another example of embodiments, projection screens are used instead of Liquid Crystal Displays. The projection screens can be front projection screens, rear-projection screens or a combination of both.

Figure 7 gives a schematic representation of a front projection display comprising three front projection screens (8, 9 and 10) and three projectors (11, 12 and 13), each projector projecting an image on one of the three projection screens.

Directional screens can be used to further improve the system. Examples of such screens are described in e.g. W02015036501 “Multi-screen projector settings” which is incorporated herewith in its entirety. In fact the second and third display surfaces 2 and 6 are each at angle to the first display surface 1 (see Figure 1) and can be configured so that the second and third display surfaces 2 and 6 are adapted to reflect light projected onto them predominantly or exclusively in one or more angular ranges that do not intersect with the first display surface 1. The second and or third display surfaces 2 and 6 can be lenticular screens. The thickness of the screens comprising the second or third display surfaces 2 and 6 need not be constant in at least one direction across the screen, for example the thickness of the screen comprising the second or third display surface 2 or 6 can vary in a sawtooth pattern in at least one direction across the screen.

This sawtooth pattern can be rotated away from the first screen comprising the first display surface 1 over an angle between 5° and 45°. The sawtooth pattern can have a surface with reduced reflectivity.

Indeed such directional screens decrease the cross talk between the lateral screens and the central screen as well as better direct the light of a lateral screen towards the corresponding eye of the viewer 3 (i.e. light from the lateral screen on the right of the viewer towards the right eye of the viewer and light from the lateral screen on the left of the viewer towards the left eye of the viewer).

As was the case with the Liquid Crystal displays, the difference in light intensity illuminating the right eye and the left eye should be at least a factor 5 and preferably a factor 10 to induce the Pulfrich effect significantly. A lower difference in light intensity may still induce a Pulfrich effect albeit not as pronounced. At least one test subject reported a difference in how he perceived the images and that the moving pictures appeared more lifelike with lateral illumination than without lateral illumination. This indicates that a positive impact on the viewer’s experience may be expected as long as light emitted by one of the lateral screens will illuminate preferentially one of the eyes of the viewer as described earlier. In particular, in a theater, viewers located at different positions with respect to the screens may experience the Pulfrich effect differently but they are expected to perceive it at various degree as long as the lateral screen on their left is in the monocular field of view of their left eye and/or as long as the lateral screen on their right is in the monocular field of view of their right eye. A higher difference between the light intensity illuminating the retinas of the left eye and the right eye by a factor 10 or more will induce a more pronounced effect. Such differences in light intensity are for example achievable either for very dark central images and / or for displays with high and very high dynamic ranges (with minimum luminance lower than 5 and preferably 1 cd/m2 and maximum luminance higher than 50 cd/ m2 and preferably higher than 100 cd/m2). This is expected to be the case for large LED displays used in lieu of projection screens, tiled LCD displays and new generations of HDR (High Dynamic Range) projection displays for which the maximum luminance is at least 100 cd/m2.

In another example of embodiments, different types of displays are used: the central display 1 can be a projection screen and the lateral screens can be LCD displays or LED displays.

In order to evaluate whether or not variation in luminance (to be expected with moving pictures) on the lateral screens would impact negatively the Pulfrich effect, tests were carried out with simple patterns.

In a first test, the luminance of a lateral screen was cycled by displaying a black image all over the lateral screen for a time interval T1 followed by a white image all over the lateral screen for a time interval T2. The first image is seen on figure 22 and the second image is seen on figure 23.

The flickering on the lateral screen 2 was described as irritating by one test subject, regardless of the configuration for the central display 1 and the lateral display screen 2. The Pulfrich effect was seriously affected for T1 > Is, moving objects (same test film as on Figure 3 and corresponding description) being alternatively perceived in front of the screen or within the plane of the screen. The Pulfrich effect was somewhat affected for T1 between 0.5 s and Is and the Pulfrich effect being less and less affected as T1 further decreased below 0.5 s.

Tests were also carried out where the average luminance of the image displayed on screen was more or less constant even though the image varied with time. In the tests, a first image was displayed for a time T1 and was followed by a second image for a time T2 and the sequence was repeated for up to 30 seconds. In those tests, T1 was always equal to T2.

In those tests, the test subject reported that the sequence of images displayed on the lateral screen affected the perception of the Pulfrich effect less and less as the distance between the lateral screen and the test subject (viewer 3) increased. In particular, this was true for the images seen on Figures 20 and 21 (where the left half of the screen is white and right half of the screen black for a time T and the left half of the screen turns black and the right half of the screen turns white for a time T).

The distance between lateral display and test subject had less and less impact on how the Pulfrich effect was perceived when the “patches” of images for which the luminance varied were small when compared to the area of the lateral display 2 within the monocular field of view of the viewer on the same side as lateral display 2. For instance, cycling through images seen on figure 16 and 17 had less impact than cycling through images seen on 18 and 19. A test subject reported that cycling through images seen on figure 14 and 15 had hardly any effect.

The impact of the distance between the lateral display 2 and the corresponding eye of the viewer 3 is linked to the monocular field of view of that eye. Indeed, in an extreme case, with images like those on figure 20 and 21, depending on the precise position of the viewer 3 facing the central display 1, the eye will see the white (bright) part of the image (and not the other half) for T second and will see the black (dark) part of the image for the next T seconds. As the distance between the viewer 3 and the lateral display 2 increased, the entire image displayed on the lateral display 2 was within the monocular field of view of the eye on the same side of the viewer as the lateral screen. The luminance over the entire screen of display 2 being constant, so is the intensity of the light reaching the retina of the eye. The test subject reported that in those cases, even long T had little or no impact on the perception of the Pulfrich effect, moving objects were clearly perceived in front of the screen as if the image on the lateral display 2 was not changing.

In a theater, where large screens are used, one should thus avoid large variations of luminance over large surfaces. This is to avoid that the part of the lateral screen in the field of view of at least one viewer close to the lateral screen would be predominantly filled in by a part of the screen where large variations of luminance will occur.

Assisted Pulfrich description

Another aspect of the current invention is to provide a device for viewing three-dimensional effects in at least one motion picture displayed on at least one display surface, according to the Pulfrich effect.

Such a device comprises at least one means for increasing the illumination entering a right (left) eye of a viewer compared to the illumination entering the left (right) eye and vice versa. Optionally, this can be done either with or without reducing the illumination entering the left (right) eye. At least one object in images displayed on the display surface are moved generally in a horizontal direction which corresponds to the movement of the right (left) eye to the left (right) eye, as illustrated in figure 2.

In the example illustrated in figure 2, the means for increasing the illumination are provided on the right eye of the viewer, in order to visualise the Pulfrich effect when at least one object in the displayed motion picture is moving from right to the left, as illustrated in figure 3 when viewing a video of a merry go round. Of course, for a movement going from left to right, the means for increasing the illumination are provided on the left eye.

The means for increasing the illumination are usually provided for both eyes and the light is increased according to the movement of objects in the motion picture.

Therefore, a control unit is provided for increasing the illumination of the first and/or second means according to command signals correlated to the displayed images of the displayed motion picture dependent upon horizontal movement of an object in the displayed images (optionally when at least one object is moving horizontally from left to right or right to left).

Real time motion detection algorithms may automatically detect a movement in the motion picture, and trigger the emission of command signals to the control unit, or the command signals can be pre-calibrated and emitted during the viewing of the motion picture. This embodiment is preferable as the light emitted by the means for increasing may then be increased progressively before the movement starts so as to be clearly seen by the viewer while viewing the motion pictures.

Tests were carried out with solid state, e.g. LED light sources and incandescent light sources to illuminate preferentially one of the eyes of a viewer V looking at moving images on a screen. The purpose of the tests was to determine whether or not it would be possible to induce the Pulfrich effect in a theater without using an absorbing filter in front of one of the eye of the viewers but instead to manipulate the light enetering the eyes of the viewer directly.

This problem involved solutions depending on antagonistic parameters. The solution had to be selective enough to allow illumination of one eye only (in order to induce a substantially different illumination of the retina of the left eye and the right eye) and applicable to a large audience of tens or hundreds of viewers. For application with a Barco Escape™ Display System, the solution had also to be as unobtrusive as possible, which excluded the use of filters and the associated glasses. The sought after solution had to keep the field of view of the viewer free. No discontinuity (caused by e.g. the rims of 3D glasses) was allowed in order not to spoil the immersive experience of the viewer.

It appeared from tests carried out with test subjects of European and East Asian descent that three positions to locate a light source close to the eye yielded better results. These positions are shown on figure 8 and are “A” adjacent to the lateral cantus and at the level of or below the lateral hooding area of that eye, “B” at the level of or below the lower eyelid and “C” close to the medial canthus. The three positions were also advantageous to viewers wearing prescription glasses as the glass reflected part of the light back towards the eye of the viewer and thereby enhanced the effect. In the three positions, the light emitted by the light source was emitted in the general direction of the pupil.

In a first example of an embodiment of the present invention, a headset 91 seen on Figure 9 can be positioned on the head as seen on Figure 10. In this example, the headset has two lateral arms 91a and 91b extending from the back of the head. When worn by a viewer, the extremities of the arms 91a and 91b are close to the eye of the viewer wearing the headset 91. The extremity of each the arms 91a and 91b supports a light source such as a solid state lamp of which an LED (Light emitting diode) is one example. A light source such as LED 92 is fastened to the arm 91b and a light source such as LED 93 is fastened to the arm 91a. Each light source such as an LED is connected to control electronics, e.g. on a Printed Circuit Board 95 by means of a cable such as a twisted cable pair 94 (shown only for light source, e.g. LED 92 on figure 9). The electronics can include a switch to activate either the light source such as LED 92 or the light source such as LED 93 which is controlled depending upon the horizontal motion on the screen to be viewed.

In the first version of an headset 91 that was used to evaluate the present invention, a connector 96 at the other end of the twisted cable pair 94 made it easier to connect and disconnect the light source such as the LED from the electronics, i.e. the PCB. The electronics, i.e. the PCB may accommodate a battery support 97 (to accommodate e.g. 3 AAA or AA batteries 97b) or it may itself be provided with a cable such as a twisted cable pair to connect to a power supply. The purpose of upper arm 91c is to help maintain the position of the lateral arms 91a and 91b.

In the first version of the headset 91, the electronics, i.e. PCB 95 accommodated two potentiometers 98 and 99, one for each of the light sources e.g. LED’s on arms 91a and 91b. The potentiometer was used to vary the amount of light emitted by the light source, e.g. LED 92 and 93. Test subjects were requested to change the potentiometer settings to adjust the light level illuminating their eyes so that the Pulfrich effect would be visible without causing them discomfort. The tests were carried out with the moving pictures described earlier (see figure 3 and corresponding description). The tests were carried out with different types of displays. LCD displays with a refresh rate of 48 frame per seconds or more and with dimensions 60 mm X 35 mm; 310 mm X 17,5 mm and 890 mm X 500 mm. Tests were also carried out with projection displays: a digital cinema projector DP2K-20C from Barco as well as a variety of smaller projectors used in meeting rooms.

It appeared during the tests that a test subject found the use of the headset more pleasing (less intrusive) when the light source e.g. an LED was turned ON gradually, over the course of e.g. 0.5 second to 1 second or more.

The position of the light sources LED 92 and LED 93 is adjustable. The test subject can move the light source, i.e. LED 92 forward and backward. In a first version of the headset, the light source, e.g. the LED was soldered on a small PCB and the PCB fastened to the arm 91a by a ring that could slide along the arm 91a. This is not shown on figure 9 and 10.

An alternative to a sliding mechanism to adjust the position of the light sources, e.g. LED 92 and 93 is to increase the area of the light source as shown on figure 11. One or more light sources, e.g. LEDs 92, 92a, 92b .. .are positioned in a cavity 100 and covered by a diffuser 110, light exiting the diffuser to illuminate the eye. With this alternative, the result is not as sensitive to the exact position of the headset. The bottom of the cavity can be coated with a reflective layer (e.g. silver paint, aluminum foil, etc...)

Figure 12 shows the schematic of the circuit that were used with the first version of the headset (limited to light source, e.g. LED 92, an identical circuit was used for light source, e g. LED 93).

The positions for the light sources, LED 92 and 93 that seem to be the best trade-off between the perceived amplitude of the Pulfrich effect and viewer experience (no or little negative sensation on nose etc..., no or little disturbance in the viewer’s field of view) is close to the lateral cantus and at the level of or below the lateral hooding area of the eye (the light will reach the retina from the side) or below the lower eyelid (the light emitted by the LED will reach the retina from below the eye).

Tests were carried out with green, red, blue and white light sources, e.g. LEDs. The test subject preferred the white and blue light source e.g. LED with a marked preference for the white light source, e.g. LED.

The light source, e.g. LED is for instance a “cold white” LED with a maximum light output of less than 10 Cd.

Generating any color in the visible part of the spectrum is included within the scope of the present invention. If used in conjunction with a Barco Escape™ Display System (as illustrated on figures 7 and 13) it may be advantageous to match the color of the light emitted by one of the light sources, e.g. LED 92 and 93 with a color of the images projected on the lateral screens. For instance, if a dominant color on the left side of a viewer is blue (e.g. a landscape with a blue sky is projected on the screen on the left of the viewer), the light source close to the left eye will be driven to emit a blue or bluish light). The light source can be for instance a set of red and green light sources, such as Red Green and Blue LEDS with which different colors can be generated. Those light sources, e.g. LEDs can be discrete LEDs associated to a diffuser or a multicolor LED. When used in conjunction with a Barco Escape™ display system, the light emitted by a lateral screen and the light source, e.g. LED on the same side of the viewer can be used in tandem to enhance the Pulfrich effect. The intensity of the light illuminating the retina of e.g. the right eye results from light emitted by the light source, e.g. LED on the right side of the viewer, the light from the lateral screen on the right of the viewer, the front screen and any ambient light. The total intensity being larger than the intensity caused by either source of light on its own, the perceived amplitude of the Pulfrich effect (i.e. how far behind of before display 1 on figure 2 or screen 9 on figure 7 and 13) is greater.

In another example of embodiment seen, the headset allows the positioning of other light sources below at the level of or below the lower eyelid and/or close to the medial canthus.

An extension of the arms 91a and 91b extends along the face of the viewer below the lower eyelid until the vicinity of the medial canthus. Additional sources of light can be positioned below the eyelid and/or close to the medial canthus on those extensions.

In another embodiment, the light sources, e.g. LED 92 and 93 are replaced by light funnels or light concentrators that collect the light emitted by one of the lateral screens in a Barco Escape™ display system as on figure 7 and 13 (the angle between a lateral screen 8 or 10 and the central screen 9 is 102.5 degrees). On figure 13, only the central projector 12 has been represented. The light is collected and by refraction and/or reflection, it is directed towards the corresponding eye of the viewer (i.e. light of the lateral screen on the left of the viewer is redirected towards the left eye of the viewer and light of the lateral screen on the right of the viewer is redirected towards the right eye of the viewer).

The light funnel can be a hollow and flexible light guide. It can also be an optical fiber or a bundle of optical fibers (a full light guide). The light guide can be a molded PMMA structure with a reflective coating on the outer surface.

Figure 6 illustrates another embodiment of a device 1400 according to the invention.

The device comprises a support structure, which in this embodiment has the shape of a headband 1420 which goes behind the head of the viewer. The headband has preferably two curved parts 1422 such that the headband goes around the ears, which increases the support. The headband may further comprise in-ears loud speakers 1430 designed to penetrate partially inside the ears. This feature further increases the support of the support structure when carried by a viewer. It also allows the viewer to hear the soundtrack of the moving picture via the headset device. However, the invention is not limited to in-ears loudspeakers and may comprise any type of loudspeaker used for headsets.

In a proximity of the in-ears loud speakers, around the ears when the device of figure 6 is carried, a compartment 1410, 1415 is foreseen, for example on each side of the device, for carrying a control unit, a receiver, and a power supply. The power supply could also be on one side and the control unit with the receiver on the other side.

Light sources, e.g. LEDs 92 and 93 are attached to the device 1400 by two plates 1440, 1450 respectively extending from compartments 1410, 1415.

At an extremity of each plate 1440, 1450, two movable parts 1445, 1455 are attached to the plates preferably by a sliding mechanism. The light sources, e.g. LEDs 92 and 93 are fixed to the movable parts 1445 and 1455 respectively, on the inner side such that when the device is carried, light emitted by the light sources, e.g. LEDs is going towards the viewer’s eyes.

The movable parts 1445, 1450 are preferably capable of sliding on plates 1440, 1450 in horizontal direction such as to adapt to distance of the light sources, e.g. LEDs to the eyes when the device 1400 is carried by the viewer, and in a vertical direction such as to adapt the height of the light sources, e.g. LEDs 92, 93 with respect to the viewer’s eyes. The device of figure 6 may be plugged directly in a viewer’s seat, wherein two cables are provided: one for transmitting the audio signals, and one for transmitting the command signals.

In another preferred embodiment, the device 1400 comprises a wireless connection such as a WiFi connection or Bluetooth for 3D sound. Preferably, the command signals are transmitted to the device by an invisible radiation such as infra-red or other undetectable means such as a wireless connection , e.g. Bluetooth wavelengths, or ultrasound to change the light sources e.g. LEDs from one side to the other in dependence upon the horizontal motion of objects on the observed screen.

In a preferred embodiment, the loud speakers are configured to provide soundtrack synchronized with the motion picture. In a most preferred embodiment, the sound transmitted provides three dimensional audio effects. In a preferred embodiment, the techniques to render three-dimensional audio effects comprise binaural recording, and most preferably holophonic™ recording.

In another embodiment, the means for increasing the illumination in a viewer’s eye, is incorporated directly in a viewer’s seat, or in a “U-shaped head support pillow” attached to the seat. The light source can be attached to a brass coil neck, incorporated in the seat, which is flexible and whose position can therefore be manually set by the viewer. In another embodiment, a head support could be included in the seat in order to provide additional comfort to the viewer but also to remove the disturbance generated by the light sources of neighbouring viewers. When a pillow is used, the latter could be fixed by quick fixing means, such as Velcro™.

The arrangement of display surfaces according to embodiments of the present invention, as well as the Barco Escape™ setting may be installed temporarily, to visualize motion picture which are adapted to more than one screen and adapted to the device and screen arrangement according to the current invention.

An arrangement according to embodiments of the present invention can be installed in a special theatre, a cinema with back projection, an opera, a conference room, a concert hall, in a room or for an outdoor cinema at night. The lateral screens of the Barco escape setting could be installed using the invention disclosed in the patent application US 2013-0278147 Al, or WO 2015/063116 .

Instead of using front or back projectors large size LED displays without projector can be used, e.g. LED walls. LED panels having a higher luminance would allow for a better Pulfrich effect. The two side screens can be back projection screens and the front screen can be front projection - thus allowing an old cinema to be updated with lateral back projection side screens. The back projection on the sides can be multiple back projections, e.g. with the projected images blended together. This helps to reduce the depth of the side screens.

The back projection screens could be set up temporarily - allow an add-on to existing cinemas that can be tom down after use.

Claims (49)

Claims.

1. An arrangement of a first, second and third display surfaces on which either or both of still or moving images are to be displayed for viewing by a viewer with a left and a right eye, - the third display surface being positioned in front of the viewer, - the first display surface being positioned so that the viewer has the first display surface on a right side, - the second display surface being positioned so that the viewer has the second display surface on a left side; a first means for increasing a first ratio of the illumination entering the right eye of the viewer compared to the illumination entering the left eye dependent upon at least one object in images on the third display surface moving generally in a horizontal direction, and a second means for increasing a second ratio of the illumination entering the left eye of the viewer compared to the illumination entering the right eye dependent upon at least one object in images on the third display surface moving generally in a horizontal direction, and wherein the first and second means for increasing the illumination are controlled by a control unit for automatically switching between the first and second ratios, so as to create 3D images according to the Pulfrich effect.

2. Arrangement according to claim 1, wherein the first and/or second ratio is 5 or more or at least 10.

3. An arrangement according to claim 1 or 2, wherein the control unit is adapted to receive command signals correlated to the displayed images according to the horizontal moving direction of the at least one object.

4. Arrangement according to claim 3 , wherein said command signals are transmitted by fat least one of infrared light, or radio wavelengths or ultrasonic or infrasonic sound

5. Arrangement according to any of claims 1 to 4, wherein the first and second means for increasing the illumination further comprise at least one light source positioned in a monocular field of view of respectively the left and right eye.

6. Arrangement according to any of claims 1 to 5, wherein the at least one light source is any of the first to third display surface.

7. Arrangement according to any of claims 1 to 6, wherein the display surfaces comprise at least one of an LCD, an LED, a projection screen, a back projection screen, an LED wall, a CRT or a plasma fixed format display.

8. Arrangement according to any of the preceding claims, wherein a louver is provided for positioning on the dorsum of the viewer’s nose

9. Arrangement according to any of claims 1 to 8, wherein the at least one light source is an incandescent source.

10. Arrangement according to any of claims 1 to 9, wherein the first means for increasing the first ratio and/or the second means for increasing the second ratio comprises at least one light source.

11. Arrangement according to claim 10, wherein said at least one light source emits at least one of white, red, green, blue light or any combination thereof.

12. Arrangement according to any of the previous claims; wherein the first means for increasing the first ratio and/or the second means for increasing the second ratio comprises at least one light source positioned in a proximity of respectively the left and right eye.

13. Arrangement according to claim 12, wherein the at least one light source is positioned adjacent to the lateral cantus, at the level of or below the lateral hooding area of the eye, or at the level of or below the lower eyelid or close to the medial canthus.

14. Arrangement according to any of the previous claims, wherein at least one of the display surfaces is a front projection screen.

15. Arrangement according to any of the previous claims, wherein at least one of the display surfaces is a back projection screen.

16. Arrangement according to claim 15, wherein the back projection screen comprises multiple back projectors.

17. Arrangement according to claim 16, wherein to reduce the depth of the side screens multiple back projection units are provided for projecting a multiple of images on to display surface.

18. Arrangement according to any of claims 14 to 17, wherein the back projection screens are set up for temporary use.

19. Arrangement according to any of the previous claims, wherein the arrangement is installed within a cinema, a theatre, an opera, a conference room, a concert hall, in a room or an outdoor cinema at night.

20. A method for a viewer to visualize 3D images with a left and right eye, the 3D images being displayed in an arrangement of surface displays, the method comprising the steps of - increasing a first ratio of an illumination entering the right eye of the viewer compared to an illumination entering the left eye dependent upon at least one object in images on a display surface moving generally in a horizontal direction, and - increasing a second ratio of an illumination entering the left eye of the viewer compared to an illumination entering the right eye dependent upon at least one object in images on the display surface moving generally in a horizontal direction, and controlling which of the first and second ratio is select so as to create 3D images according to the Pulfrich effect.

21. A device for viewing three-dimensional effects in at least one motion picture displayed on at least one display surface, the device comprising : first means for increasing a first ratio of an illumination entering the right eye of a viewer compared to an illumination entering the left eye when at least one object in images displayed on the at least one display surface is moving generally in a horizontal direction , second means for increasing a ratio of an illumination entering the left eye of the viewer compared to an illumination entering the right eye when at least one object in images displayed on the at least one display surface is moving generally in a horizontal direction, wherein the first and/or second ratio is five or more or at least nine and the first and second means for increasing the illumination are controlled by a control unit for automatically switching between the first and second ratios, so as to create 3D images according to the Pulfrich effect.

22. Device according to claim 21, wherein the control unit is adapted to receive command signals correlated to the displayed images of the at least one motion picture according to the horizontal moving direction of the at least one object.

23. Device according to claim 22, wherein said command signals are transmitted with an invisible light, radiofrequency waves.

24. Device according to any of claims 21 or 22, wherein said command signals are transmitted by at least one of ultrasonic sound, or infrasonic sound.

25. Device according to any of claims 21 to 24, wherein the first and second means for increasing the first and second ratio further comprise at least one light source for being positioned in a monocular field of view of respectively the right and left eye.

26. Device according to any of claims 21 to 25, wherein the first and second means for increasing the first and second ratio comprise at least one light source.

27. Device according to any of claims 21 to 26, wherein the at least one light source is a solid state light source or is an incandescent source.

28. Device according to claim 27, wherein said at least one light source emits at least one of white, red, green, blue light or any combination thereof.

29. Device according to claim 28, wherein said at least one light source is a set of discrete LEDs associated to a diffuser or a multicolor LED.

30. Device according to claims 6 to 29, wherein the at least one light source is positioned in a proximity of respectively the left and right eye.

31. Device according to claim 30, wherein the at least one light source is for positioning adjacent to the lateral cantus, at the level of or below the lateral hooding area of the eye, at the level of or below the lower eyelid or close to the medial canthus.

32. Device according to any of claims 21 to 31, wherein the first and second means for increasing the first and second ratio are mounted or attached by fixing means to a support structure adapted to maintain the first and second means for increasing the first and second ratio comprise in a position relative to the head of the viewer.

33. Device according to any of claim 32, wherein the support structure is one of a tiara, hard headband, cloth headband, plastic headband, wherein the headband goes over or behind the head, headphones, earphones, glasses, goggles, security glasses, hat, helmet, head accessory, or any type of hair accessory.

34. Device according to any of claims 32 to 33, wherein the support structure is configured to maintain a louver, which, when the support structure is placed on a viewer’s head, the louver is positioned close to the root and/or dorsum of the nose.

35. Device according to any of claims 32 to 34, wherein the control unit is configured to be attached by fixing means or is mounted to said support structure.

36. Device according to any of claims 32 to 35, wherein the fixing means can be at least one of glue, magnets, clipping mechanism, Velcro™. ...

37. Device according to any of claims 21 to 36, wherein a mobile phone is used to receive command signals and control the first and second means for increasing the first and second ratio.

38. Device according to any of claims 21 to 37, wherein said device is used in conjunction with a Barco Escape™projection system comprising a first and second lateral screens and a third main screen .

39. Device according to any of the claims 26 to 38, wherein the color of the at least one light source is selected to match a color of the images projected on the first and/or second lateral screens.

40. Device according to claim 38 or 39, wherein the first and second means for increasing the first and second ratio comprise means for collecting light emitted by the first and second lateral screens of the Barco Escape projection system.

41. Device according to claim 40, wherein the means for collecting light emitted by the first and second lateral screens comprise a hollow or full light funnel.

42. Device according to any of claims 38 to 41, wherein first and second means for increasing the first and second ratio further comprise a reflecting surface fastened to the support structure of a device positioned adjacent to the root and dorsum of the nose to reflect light into the eye.

43. Device according to claim 42, wherein the reflecting surface is an integral part of a louver for positioning on the dorsum of the nose of the viewer.

44. Device according to any of claims 38 to 43, wherein the apparatus is powered and command signals are transmitted by light projected on the lateral screens.

45. Device according to any of claims 21 to 44, wherein the device further comprises a light sensor for measuring the ambient light.

46. Device according to claim 45, wherein the control unit further comprises means to control the intensity of the illumination provided by the means for increasing the light entering an eye as a function of the ambient light provided by the sensor.

47. Device according to any of the claims 21 to 46, wherein light projected can be infra-red light projected by one of the projectors or by a dedicated infra-red projector.

48. Device according to any of the claims 21 to 47 used in conjunction with an emissive display.

49. A method of using the device according to any of the claims 21 to 48, for viewing three dimensional images according to the Pulfrich effect.