Autostereoscopic P viewpoint display screen for displaying autostereoscopic I viewpoint images and display device including such screen

Abstract

The present invention relates to a display screen with P screen viewpoints, P being an integer greater than or equal to 6, and intended to display an autostereoscopic image with I image viewpoints, I being an integer greater than or equal to 2 and less than or equal to P / 3, the screen comprising: a pixel matrix (10) arranged in rows and columns; an optical array configured so that the P viewpoints of the screen can be perceived continuously in lobes, each lobe covering I times the average interpupillary distance of an observer (8), and so that the screen viewpoints of each pair of viewpoints visible to the observer are separated by at least T buffer viewpoints, T being greater than or equal to 2, so that each of the I image viewpoints can be displayed continuously for each lobe, each repeated P / I times, and each viewpoint visible to the observer can be surrounded by at least 2 buffer viewpoints, each buffer viewpoint displaying the same image viewpoint.

Description

Technical Field

[0001] The invention relates to an autostereoscopic display screen for autostereoscopic images and a display device comprising such a display screen. The invention also relates to a method for displaying autostereoscopic images on such a display screen. Background Art

[0002] The autostereoscopic technique is a technique for displaying images in relief without requiring the observer to wear special glasses. This technique itself constitutes prior art, in particular with reference to the patent documents WO2006 / 024764, WO2014 / 041504, WO2013 / 140363 and WO2014 / 016678 registered in the name of the applicant.

[0003] Typically, an autostereoscopic image consists of a plurality of nested elementary images, each elementary image corresponding to a view of the same object or the same scene according to a different viewpoint. A selector device, typically constituting an array of cylindrical lenticular lenses or a parallax barrier, is arranged in front of the display screen so as to allow a pair of elementary images corresponding to two different viewpoints of a single scene to be projected to each of the two eyes of the observer, which creates an impression of relief in the observer's mind.

[0004] The screen displaying the P-viewpoint autostereoscopic screen image usually comprises a matrix of pixels arranged in rows and columns, each pixel consisting of a number of sub-pixels of different colors. The screen is also covered with an array of identical cylindrical lenticular lenses, each of which has a focal length configured so that light from the screen is returned an infinite number of times. The spacing of the cylindrical lens array is precisely calculated so that an observer at a predetermined distance from the screen (called the flat tonal distance) sees that the image is continuously shifted at regular intervals due to the magnifying effect of the lens array.

[0005] This magnification effect is due to the fact that a lens placed at the correct distance (its focal length) magnifies the sub-pixels that are aligned with its optical center and the pupil of the observer's eye. If the lens is magnified by a factor of P, the sub-pixels seen through the lens are perceived as wider than they actually are, and obscure P-1 other sub-pixels that are not in the above alignment from the perspective of the eye receiving light through the lens.

[0006] The cylindrical microlens array thus forms a viewpoint selector device configured to allow a pair of different viewpoints corresponding to two different viewpoints of the scene to be projected respectively to the two eyes of an observer in the viewing space of the screen.

[0007] When certain elements of the two images observed by the left and right eye of the observer, respectively, do not show parallax (defined as the difference measured in pixels or sub-pixels, observable and / or measured between the left and right), these elements are perfectly superimposed and are then perceived in the plane of the screen. On the other hand, when there is parallax between the observed elements, the latter burst out of the screen or, conversely, are perceived in depth. By convention, depth corresponds to positive parallax and burst to negative parallax. The shift in absolute value between the two images is the same in both cases, but when the parallax is negative, the burst elements of the left image are to the right of the burst elements of the right image and vice versa. It is this shift that creates a burst effect (the two eyes converge in front of the screen). On the other hand, when the parallax is positive, the depth elements of the left image are to the left of the depth elements of the right image and vice versa (the two eyes converge behind the screen).

[0008] Since the offset of dots in the horizontal plane between the left and right images is significant, dot-sized objects are perceived as being further away from the plane of the screen.

[0009] Current autostereoscopic screens face limitations in depth and burst that can be achieved without loss of quality. These screens can register projected content in a viewing cube with a depth close to the diagonal of the screen. The screens are often used in such a way that one third of the visualization cube pops out of the screen and the remaining two thirds are perceived at depth behind the plane of the screen.

[0010] For example, on a 24" screen this means a standard viewing cube could have a full range of approximately 60cm, a comfortable burst of 20cm in front of the screen and a background of 40cm behind the screen.

[0011] These depth and burst limits are explained by observer physiological constraints, technical constraints, and image processing constraints.

[0012] The physiological constraint is due to each eye of the observer seeing a different image in order to be able to form a stereo pair, which the observer merges by converging his gaze at the place where the parallax appears to place the objects in space.

[0013] The parallax between the left and right images causes three different convergence modes:

[0014] -When the observer perceives an object in depth behind the screen, the left eye looks more to the left and the right eye looks more to the right. Therefore, the two optical axes intersect behind the screen and the observed virtual object is behind the screen,

[0015] -When the observer perceives the object in the same plane of the screen, both eyes look at the same place on the screen,

[0016] -When the observer perceives the object bursting in front of the screen, the left eye looks more to the right and the right eye looks more to the left. Therefore, the two optical axes intersect in front of the screen and the observed virtual object is located in front of the screen.

[0017] When objects are perceived in depth or in burst, fixations converge at different distances from the plane of the screen. This necessarily leads to the above-mentioned separation between different convergences and accommodations, which must correspond to the effort of each eye to see a clear image at a certain distance from the screen.

[0018] The farther the object is from the plane of the screen, the greater the effort required to separate the plane of convergence and the physical plane of the screen where the eye accommodates. However, all observers are not equal when it comes to the ocular gymnastics necessary to operate this separation. Only experience and training allow for effortless separation of vergence and accommodation. If you are not used to it, objects may appear blurry or even split when you converge from the screen surface, and binocular fusion becomes difficult. As in the physical world, the eye seeks clarity at the distance at which they converge and at the location of the virtual object, even if the two images never leave the physical surface of the screen.

[0019] The technical constraints stem from the fact that it is technically complex to display several images simultaneously on an autostereoscopic screen and to separate them perfectly for each eye.

[0020] In fact, and as mentioned above, an autostereoscopic screen consists of a screen and an optical system placed on its surface. This optical system makes it possible, by a magnifying effect, to subdivide the viewing area of ​​the screen into successive zones, each reserved exclusively for a different image. To see the relief, these images must at least form a stereoscopic pair. It is usually not enough to display only a single pair of two images, and most of the screens proposed by the applicant display a series of eight images simultaneously, two by two stereoscopically. The space formed by the eight successive zones occupied by each of these eight images is designated by the term lobe, which the optical system enables to be repeated periodically. The succession of viewpoints is always in the same order. This repeated display allows the lobes to be repeated over an angle of about 100° without the lens array becoming too out of focus.

[0021] The perfect division of the information displayed in each consecutive area of ​​the lobe remains a challenge. In fact, the light coming from the screen backlight passes through many materials before reaching the observer's eyes. Some of the light that passes through each surface of these different materials deviates slightly from its ideal trajectory. In addition, in order to limit the diffusion of the emitted light, the surfaces of the screen and the lens array must be perfectly polished glass and free from any internal inhomogeneities, such as frosting of the material itself, to often obtain an anti-reflective surface. Each tiny imperfection can deviate the light and interfere with the refractive effect of the microlenses used to separate the viewpoints. The shape of the pixels and the fact that the optical axis of the lenses can simultaneously intersect the sub-pixels assigned to different viewpoints prevent this division.

[0022] Image processing constraints stem from the fact that computer processing options depend on a certain number of parameters, including the number of viewpoints, their repetition, the width of the lobes, the viewing distance and the number of simultaneous observers. The electronic devices of the screen or computer can apply modifications that can be detected in the content of the image to be displayed, which have the effect of modifying the strictly necessary positioning. For example, by modifying the intensity of the entire pixel, its three sub-pixels are affected simultaneously, i.e., three viewpoints are affected simultaneously (in the case of using a single sub-pixel per viewpoint picture).

[0023] The applicant has proposed a system equipped with a device for tracking the head of an observer to enable real-time display of the viewpoint to be sent to each eye of the observer. The farther the object is from the plane of the screen, the more critical the tracking speed and accuracy. Small movements of the head then lead to noticeable displacements of the object, especially when the object is very deep, which is one of the purposes of the invention.

[0024] The inventors therefore sought a solution that would enable at least some of the above limitations to be overcome. Purpose of the Invention

[0025] The present invention aims to provide an autostereoscopic display screen which makes it possible to overcome the limitations of burst and depth achievable with known autostereoscopic screens.

[0026] The invention is particularly intended to provide a screen with almost perfect resolving power, which makes it possible for the observer to perceive burst volumes up to half the flat tonal distance and depth volumes up to several meters behind the plane of the screen, without any practical limitations, while maintaining optimal display clarity for each eye, although significant parallax must be registered in the content to achieve this.

[0027] The invention aims in particular at providing a display screen making it possible to enhance the relief properties of known screens while maintaining or even improving the quality of the image observed.

[0028] The invention is particularly intended to provide a screen for displaying autostereoscopic images which has a greater resolution capability than known screens.

[0029] The invention also aims to provide a display screen which makes it possible to limit interference between viewpoints visible to each eye of an observer.

[0030] The invention also aims to provide an autostereoscopic display device comprising a display screen according to the invention.

[0031] The present invention finally aims to provide a method according to the invention for displaying autostereoscopic images on an autostereoscopic display screen. Invention Disclosure

[0032] To this end, the present invention relates to an autostereoscopic display screen with P viewpoints (called screen viewpoints), P being an integer greater than or equal to 6, intended to display autostereoscopic images with I viewpoints (called image viewpoints), I being an integer greater than or equal to 2 and less than or equal to P / 3, preferably equal to 2, said screen comprising:

[0033] - a matrix of pixels arranged in rows and columns, each pixel consisting of a number of sub-pixels of different colors, each of which is intended to display a sub-pixel of one of the image viewpoints,

[0034] - An array of cylindrical microlenses or parallax barriers (called optical arrays) is configured to allow a predetermined viewpoint pair of the screen to be projected towards the eyes of an observer at a nominal distance from the screen (the so-called flat tonal distance).

[0035] The screen according to the invention is characterized in that the optical array is configured so that P viewpoints of the screen can be continuously perceived by the observer in a direction called the horizontal direction in a space (called a lobe) in front of the screen at the flat tone distance, each lobe covering I times the average interpupillary distance of the observer, and so that the screen viewpoints of each pair of viewpoints visible to the observer at the flat tone distance are separated by at least T screen viewpoints (called buffer viewpoints), T being greater than or equal to 2, so that each of the I image viewpoints can be displayed continuously for each lobe, each repeated P / I times, and each viewpoint visible to the observer at the flat tone distance can be framed by at least 2 viewpoint buffers, each viewpoint buffer displaying the same image viewpoint.

[0036] Therefore, the display screen according to the invention has the particularity of being provided with an optical array, such as a cylindrical microlens array (also denoted by the term optics) configured to display P viewpoints, for example 10 viewpoints (where P equals 10).

[0037] When the present invention uses a single sub-pixel per lens and per viewpoint per horizontal line, each lens of the lens array covers P sub-pixels on each horizontal line. When the present invention uses a single sub-pixel per viewpoint per lens on L horizontal lines, each lens of the lens array covers P / L sub-pixels on each horizontal line.

[0038] The screen according to the invention makes it possible to obtain almost perfect resolving power, thanks to the creation of a buffer zone formed by duplicating the image viewpoints and isolating the two viewpoints perceived by each of the two eyes from each other. I image viewpoints form I-1 consecutive stereo pairs, and these different viewpoints are separated from each other by the buffer zone created by duplicating the image viewpoints. In other words, each of the I screen viewpoints visible at the observer's flat tonal distance and each displaying an image viewpoint is surrounded by at least 2 buffer viewpoints, each displaying the same image viewpoint.

[0039] Furthermore, each lobe covers I times the average interpupillary distance of the observer, and each of the I image viewpoints benefits from the space corresponding to the interpupillary distance to display the viewpoint perceived there and its buffered viewpoint.

[0040] The present invention therefore goes against the prejudice of those skilled in the art, who generally believe that improvements in autostereoscopic systems should be accomplished by increasing the number of image viewpoints to increase the width of the lobes, the parallax and the front-to-back viewing distance of the flat tonal distance, thereby giving the viewer greater positioning freedom. This may be at the expense of perceived resolution if the screen resolution is not increased proportionally.

[0041] The invention does not seek to give the viewer greater freedom of positioning and thus free up the volume they perceive. Instead, it tends to fix their position in order to limit as much as possible the number of image viewpoints required, only two being enough, in this way obtaining an almost perfect resolving power and making possible the perception of exceptionally deep volumes.

[0042] The present invention makes it possible to create a monocular sub-lobe for each image viewpoint with a width equal to the reference interpupillary distance (approximately 6.5 cm), and to produce a device for displaying the same image multiple times in the monocular sub-lobe, so that each instance of the image is visible over a width equal to the monocular sub-lobe divided by the number of times the image is replicated.

[0043] Without the present invention, and when the content is pushed far in front of or behind the plane of the screen, parallax is very significant and the problem of ghosting is particularly severe. The image seen by each eye is likely to retain an afterimage of the image intended for the other eye. From then on, the left eye not only sees the left image prepared for it, but also sees a ghost of the right image, and vice versa, the right eye not only sees the right image prepared for it, but also sees a ghost of the left image. Now, the phantom of the right image seen in the left image is stereoscopically matched to the right image itself, and the phantom of the left image seen in the right image is stereoscopically matched to the left image itself, which locates the ghost on the front plane of the screen, rather than at the outline of the depth element.

[0044] According to the present invention, the viewpoints observed by the observer's eyes are close to being from the same image, which makes the crosstalk between them imperceptible.

[0045] As far as the images dedicated to the observer's eyes are concerned, each image is replicated several times (at least 2 times to form at least 3 identical consecutive viewpoints, counting the viewpoints observed by the observer's eyes), and each sub-pixel magnified by the lens for one eye is surrounded by sub-pixels belonging to the same image. Therefore, a sub-pixel framed by its peers can no longer interfere with the sub-pixels of the other eye. If it interferes with its neighbors, it cannot be seen.

[0046] The display screen according to the invention therefore has the particularity of allowing the display of T buffered viewpoints between the viewpoints dedicated respectively to the left and right eye of the observer.

[0047] The screen according to the invention not only makes it possible to benefit from an almost perfect resolution capability, but also presents the advantages of conventional multi-view content, namely:

[0048] - Possibility of moving away from flat tonal distance due to the re-combination of viewpoints;

[0049] - a proportional increase in the lobes, and therefore in the space in which the viewer can place his eyes;

[0050] - Parallax effect when moving horizontally along the screen;

[0051] - Ensures that in cases of very strong contrast and extreme differences, for example, any remaining ghosting is perceived at the edge of the object rather than in the collimated plane of the image. This is an undeniable advantage for applications that need to implement rendering that facilitates the perception of ghosting.

[0052] Preferably, the optical array of the screen according to the invention is formed by cylindrical lenses, each cylindrical lens having a major axis forming an angle α with the direction of the columns.

[0053] Various tilts of the optical array (between perpendicular and 45° arrays) can be used as long as a suitable viewpoint distribution grid is defined. For example, an array with lenses tilted at an angle α of 9.46°, 18.43°, 26.56°, or 33.69° can be used, as shown in the figures discussed later.

[0054] According to a particularly advantageous variant of the invention, I is equal to 2 and the optical array is configured to be able to display in each lobe M times the image viewpoints dedicated to the left eye of the observer and N times the image viewpoints dedicated to the right eye of the observer, M and N are both greater than or equal to 3 and their sum is equal to P, and by forming T buffer viewpoints between the viewpoint dedicated to the left eye and the viewpoint dedicated to the right eye.

[0055] This advantageous variant concerns a screen intended to display an autostereoscopic image with 2 viewpoints, one for the right eye and one for the left eye of the observer.

[0056] In this preferred case of displaying autostereoscopic images with 2 viewpoints (I=2), the screen is controlled to display only two different images for the left and right eye of the observer, respectively. In other words, each image is repeated several times for each eye, in this case M times for the left eye and N times for the right eye, M and N being each an integer greater than or equal to 3, and their sum being equal to P.

[0057] Furthermore, the optical parameters of the optical components are chosen so that the P viewpoints (M for the left eye and N for the right eye) cover a lobe extending over a distance equal to twice the average interpupillary distance of the observer, that is to say in practice a distance of approximately 13 cm (the average interpupillary distance of an adult observer is 6.5 cm).

[0058] Therefore, and with P equal to 10 and I equal to 2, at the flat tone distance, a screen viewpoint change occurs every 1.3 cm.

[0059] The display screen according to this variation can be designed so that the number of screen viewpoints intended to display image viewpoints dedicated to the left eye of an observer located at a flat tonal distance is equal to or different from the number of screen viewpoints intended to display image viewpoints dedicated to the right eye of the observer. In other words, the screen can be designed in such a way as to obtain a symmetrical (M and N are equal) or asymmetrical (M and N are different from each other) arrangement of viewpoints dedicated to each of the two eyes of the observer.

[0060] Preferably, M and N are equal and the screen allows a symmetrical display of viewpoints dedicated respectively to the left and right eye of the observer.

[0061] However, it is also possible to exploit an asymmetric arrangement and minimize its disadvantages by positioning the maximum number of buffered viewpoints in the region of the lobe to which the eye is directed, taking into account the direction of movement of the observer's head, and by dynamically optimizing the allocation of viewpoints in a predictive manner, by manipulating the arrangement in the part of the lobe that is not perceived by the observer's eye. This requires the use of a device for detecting the position of the observer's head, as discussed later in conjunction with the device according to the invention.

[0062] Preferably, and according to this variant, the screen is also designed so that the sum of the number of viewpoints to the left of the left eye and to the right of the right eye is equal to the number of buffer viewpoints T separating the viewpoints perceived by the two eyes of the observer.

[0063] This makes it possible to have the same number of consecutive buffered viewpoints T on each side for both eyes.

[0064] According to a particular embodiment of a variant of the invention with 2 image viewpoints (I equals 2), P equals 10, so that the screen has 10 screen viewpoints, and the array optics is configured so that the pair visible to the observer at the flat tonal distance is the viewpoint Figure 1-6 , 2-7, 3-8, 4-9 and 5-10 are used for screen viewpoints numbered consecutively from 1 to 10, so that each sub-pixel perceived by each eye of the observer can be surrounded by 2 buffer viewpoints on each side.

[0065] Therefore, and with P equal to 10 and M and N each equal to 5, the viewpoint perceived by each eye is always separated by 4 other viewpoints, which act as buffers and avoid interference.

[0066] Thus, when the right eye perceives viewpoint No. 3, the left eye perceives viewpoint No. 8. Viewpoint No. 3 is framed on its left by viewpoints No. 1 and No. 2, and on its right by viewpoints No. 4 and No. 5n, while viewpoint No. 8 is framed on its left by viewpoints No. 6 and No. 7, and on its right by viewpoints No. 9 and No. 10. In this case, the 2 viewpoints perceived by the observer are isolated from each other by 4 buffer viewpoints, which makes it possible to avoid interference. Therefore, for the screen according to this preferred embodiment of the invention, the resolution is optimal.

[0067] According to a particular embodiment of a variant of the invention with 2 image viewpoints (I equals 2), M and N are odd numbers so that each image viewpoint dedicated to each eye of the observer can be surrounded by the same number of buffer viewpoints in each lobe.

[0068] For example, and if M and N are each equal to 5 (forming a screen with 10 viewpoints), the encoding of the content of the autostereoscopic image is based on packing the stereo pair in a 10 viewpoint image format. Each sub-pixel perceived by the eye is framed by four buffered sub-pixels, 2 to its left and 2 to the right, which display the same image. Interference of the perceived viewpoint by neighboring sub-pixels is not visible because all sub-pixels display the same image.

[0069] The image is decoded by a lens array whose innovative structure has 10 viewpoints, making it possible to change the viewpoint every 1.3 cm. The average interpupillary distance is 6.5 cm, which makes it possible to insert 4 buffer viewpoints between the left and right viewpoints as required by the content. At the flat shadow distance (twice the interpupillary distance), the lobe of this array is 13 cm. This also makes it possible to cater for pupil distances different from the chosen average of 6.5 cm, which in this case is the result of a modification of the ideal symmetry.

[0070] The invention can be implemented with different pixel arrays. For example, a pixel block with horizontal sub-pixels (i.e., vertically overlapping sub-pixels) or a pixel block with vertical sub-pixels (i.e., horizontally juxtaposed sub-pixels) can be used, or even a panel with organic light emitting diodes (better known as OLED) or an active matrix with organic light emitting LEDs (better known as AMOLED) can be used.

[0071] In the particular case of a panel formed of horizontal sub-pixels, each pixel of the pixel matrix consists of a plurality of sub-pixels of different colors superimposed on each other in the direction of the columns.

[0072] For 2D displays, the orientation of the subpixels in vertical or horizontal bands has no effect on the user, who will not perceive any difference in the display depending on the screen orientation. Information is always encoded at the pixel level, and the arrangement of its substructure has no effect on the quality of the display.

[0073] For 3D displays, on the other hand, when a lens array that works by a magnification effect is adhered to the screen surface, the orientation of the sub-pixels and the regularity of their geometry become decisive.

[0074] When using a screen in landscape mode where the sub-pixels are aligned vertically in portrait mode, or when using pixel blocks with anisotropic pixel structures, the cylindrical microlenses of the lens array can no longer distinguish colors individually and must be aligned to the entire pixel. The entire pixel then becomes the smallest entity that the lens can observe individually through the magnification effect.

[0075] The invention also relates to a device for displaying an autostereoscopic image with I viewpoints, called image viewpoints, comprising:

[0076] - a display screen according to the invention,

[0077] - a display module configured to display each of I image viewpoints for each lobe, each repeated P / I times, each viewpoint visible to an observer at a flat tonal distance being framed by at least 2 buffer viewpoints, each buffer viewpoint displaying the same image viewpoint.

[0078] The technical advantages and effects of the display screen according to the present invention apply mutatis mutandis to the display device according to the present invention.

[0079] According to the invention, the display module is configured to assign to each sub-pixel of the pixel matrix of the display screen a sub-pixel of one of the I images intended for the eye of the observer. The display module is preferably formed by a computer device for controlling the pixel matrix.

[0080] Throughout the text, the term "module" means a software component, ie a subset of a software program that can be compiled separately for independent use or assembled with other modules of the program, or a hardware component, or a combination of a hardware component and a software subroutine.

[0081] Preferably, the display module of the device according to the invention is a subset of a software program intended to be executed by a computer or microprocessor connected to the display screen.

[0082] According to a particularly advantageous variant, I is equal to 2 and the display module is configured to display, in each lobe formed by the display screen, M times as many image viewpoints dedicated to the left eye of the observer and N times as many image viewpoints dedicated to the right eye of the observer, and by forming T buffer viewpoints between the image viewpoints dedicated to the left eye and the image viewpoints dedicated to the right eye.

[0083] In the preferred case where I is equal to 2, these two viewpoints are used for the left and right eye of the observer, respectively. If I is greater than 2, the central I-2 viewpoints can be seen by the left or right eye of the observer, depending on their positions.

[0084] Advantageously and according to the invention, the device also comprises means for detecting at any time the position of the observer's head relative to said horizontal and / or vertical directions, thereby allowing said display module to drag the image viewpoints in each lobe in such a way that said screen viewpoint visible to the observer is permanently framed by the buffered viewpoints of the image viewpoints visible to that eye.

[0085] The display device according to this variant makes it possible to keep the observer permanently in the center of the lobe, so that they perceive (if I=2 and N=M=5 to form 10 screen viewpoints, P=10) viewpoints 3 and 8. A lobe of twice the interpupillary distance (that is to say about 13 cm) provides a limited range of movement. Thanks to a device that tracks the observer's head, the invention makes it possible to dynamically calibrate the lobe so that it is centered on the observer's position, without forcing the observer to place himself in the center of the lobe.

[0086] Thus, the present invention makes it possible to identify the position of the observer's head relative to the screen in the horizontal and / or vertical direction (that is, to detect the lateral displacement of the observer's head relative to the screen in the case of horizontal detection), and to drag the viewpoints in the lobe so that viewpoints No. 3 and No. 8 are presented to the observer. For purposes, in this embodiment, only the position of the observer's face relative to the horizontal and / or vertical direction is identified, and a simple 2D camera is sufficient to ensure tracking of the observer's head.

[0087] According to a variant embodiment of the present invention, the detection device is configured to detect the position of the observer's head - in particular, each eye of the observer - relative to a predetermined point of the display screen at each moment, so that the coordinates X, Y, Z of each eye of the observer can be defined with a predetermined accuracy, in an orthogonal reference system in which the predetermined point of the screen is the origin of the system, the screen defines the X-axis and Y-axis of the system, and the direction perpendicular to the screen defines the Z-axis of the system.

[0088] According to this variant of the invention, the position of the observer's head is determined at each moment in three dimensions, which makes it possible to use the device according to this variant in augmented reality applications.

[0089] In particular, when the screen brightness allows, the screen can be used, not in direct view, but reflected on a half-mirror, creating an augmented reality experience of "Pepper's ghost".

[0090] The 3D volume displayed on the screen then materializes in the room and offers the possibility to create new immersive experiences, as long as we take care not to create conflicts in the relief. In particular, care must be taken that deep virtual objects do not overlap scene elements located in front of them.

[0091] The convergence / accommodation separation is no longer an issue, as the gaze relies on the physical world to converge on the virtual elements portrayed there.

[0092] When the observer is not too close to the screen, the diopter difference is small enough that clarity is perceived as good and eyestrain is minimal.

[0093] However, to be believable, an augmented reality experience must provide a perfect balance between the physical and virtual worlds. In addition to relief conflicts, which must be absolutely avoided, virtual objects superimposed on the real world must obey the same perspective rules and react to the movement of the observer in the same way as objects in the room. When the observer moves their head, the virtual cube superimposed on the material cube must look like the real object in all respects. The parallax between virtual objects perceived by the observer must also be consistent with the position of their eyes. For this purpose, it is crucial to measure the position of each pupil of the observer in three dimensions in real time with low latency and very high accuracy.

[0094] In this case, the Z measurement is particularly important. In fact, given the good resolving power of the screen according to the invention and the large depth that it makes possible to simulate, the parallax displayed produces a very different sense of volume, depending on the distance at which the content is collimated, but also on the distance of the viewer from the screen. Therefore, in order to generate an image faithful to the physical world, the real-time image rendering engine must know precisely the position of the observer's pupil on the Z axis in order to adjust the stereoscopic base and the focal length accordingly, as well as on the X and Y axes to adjust the parallax.

[0095] Therefore, the invention makes it possible to know the relative position of the observer with respect to the environment in order to adjust the virtual scene accordingly. In particular, the invention according to this variant makes it possible to know the distance of the observer's pupil from the screen in order to adjust the rendering of the virtual scene and make it consistent with the physical world.

[0096] For example, such a device could be used in flight simulators, driving construction machinery, teleoperation, or any other simulator designed to put the user in hyper-realistic conditions without the need to wear an augmented reality headset.

[0097] In this specific application context, the room may be free of objects and maintaining consistency between the physical and virtual worlds is no longer necessary. However, measurement of the pupil position on the Z axis is still necessary to adjust the stereo base and focus, just as it is necessary to adjust parallax on the X and Y axes.

[0098] The present invention also relates to a method for displaying an autostereoscopic image at I viewpoints (I is an integer greater than or equal to 2) with P viewpoints (called screen viewpoints, P is an integer greater than or equal to 6 and greater than or equal to 3I) on a display screen, comprising a matrix of pixels arranged in rows and columns, each pixel consisting of a plurality of sub-pixels of different colors, which are intended to each display a sub-pixel from one of the image viewpoints, and an array of cylindrical microlenses called an optical array or a parallax barrier, which is configured to allow pairs of viewpoints of a predetermined screen to be projected towards the eyes of an observer located at a nominal distance from the screen (called a flat tone distance), and so that the P viewpoints of the screen can be continuously perceived by the observer in one direction (called the horizontal direction) in a space (called a lobe) in front of the screen at the flat tone distance, each lobe covering I times the average interpupillary distance of the observer.

[0099] The method according to the invention is characterized in that it comprises, for each lobe, assigning a copy of this image viewpoint to each adjacent screen viewpoint of each image viewpoint visible to an observer at a flat tonal distance, so that in each lobe each of the I image viewpoints visible to an observer at a flat tonal distance is framed by at least 2 buffered viewpoints showing this same image viewpoint and because it consists of consecutive I image viewpoints each repeated P / I times.

[0100] The technical advantages and effects of the display screen according to the present invention apply mutatis mutandis to the display method according to the present invention.

[0101] According to a particularly advantageous variant of the invention, I is equal to 2 and, for each lobe, the method comprises:

[0102] - assigning image viewpoints dedicated to the observer's left eye to the first M screen viewpoints,

[0103] - assigning the image viewpoint dedicated to the observer's right eye to the subsequent N screen viewpoints,

[0104] M and N are each greater than or equal to 3 and their sum is equal to P.

[0105] The invention also relates to a display method and a display system, which are characterized by combining some or all of the characteristics mentioned above or below. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] Further objects, features and advantages of the present invention may be found in the following description, which is provided by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0107] -[ Figure 1 ] is a schematic diagram of an aircraft according to an embodiment of the present invention,

[0108] -[ Figure 2 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image at 2 viewpoints, comprising a pixel block formed of sub-vertical pixels, covered by an optical array having an inclination of 18.43° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=18.43°),

[0109] -[ Figure 3 ] is a schematic diagram of an arrangement principle of a left image and a right image on a screen according to an embodiment of the present invention,

[0110] -[ Figure 4 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 9 screen viewpoints, displaying an image with 2 viewpoints, comprising a pixel block formed by sub-vertical pixels, covered by an optical array having an inclination of 18.43° relative to the vertical direction (in other words, I=2; P=9; N=5; M=4; α=18.43°),

[0111] -[ Figure 5 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 8 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-vertical pixels and covered by an optical array having an inclination of 18.43° relative to the vertical direction (in other words, I=2; P=8; N=4; M=4; α=18.43°),

[0112] -[ Figure 6 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-vertical pixels and covered by an optical array having an inclination of 9.46° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=9.46°),

[0113] -[ Figure 7 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-vertical pixels and covered by an optical array having an inclination of 26.56° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=26.56°),

[0114] -[ Figure 8] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-vertical pixels and covered by an optical array having an inclination of 33.69° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=33.69°),

[0115] -[ Fig. 9 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-horizontal pixels and covered by an optical array having an inclination of 18.43° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=18.43°),

[0116] -[ Fig.10 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 6 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-horizontal pixels and covered by an optical array having an inclination of 26.56° relative to the vertical direction (in other words, I=2; P=6; N=3; M=3; α=26.56°),

[0117] -[ Fig.11 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 10 screen viewpoints, displaying an image with 2 viewpoints, comprising pixel blocks formed by sub-horizontal pixels and covered by an optical array exhibiting a 33.69° inclination relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=33.69°),

[0118] -[ Fig.12 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 20 screen viewpoints, displaying an image with 4 viewpoints, comprising pixel blocks formed by sub-horizontal pixels and covered by an optical array having an inclination of 9.46° relative to the vertical direction (in other words, I=4; P=20; α=9.46°),

[0119] -[ Fig.13 ] is a schematic diagram of a display screen according to an embodiment of the present invention, the display screen having 20 screen viewpoints, displaying an image with 4 viewpoints, comprising pixel blocks formed by sub-horizontal pixels and covered by an optical array having an inclination of 18.43° relative to the vertical direction (in other words, I=4; P=20; α=18.43°),

[0120] -[ Fig.14] is a schematic diagram of a display device according to an embodiment of the present invention, including a screen, a tracking device and a display module according to the present invention. Specific embodiments of the invention

[0121] For purposes of illustration and clarity, the drawings are not strictly to scale or proportion.

[0122] Figure 1 is a partial schematic diagram of an autostereoscopic display screen according to the invention, comprising a matrix of pixels 10 (also indicated by the term pixel blocks) arranged in rows and columns, which are covered with an optical array 11 of cylindrical microlenses. The optical array 11 is partially shown, but it is clear that it extends in practice over the entire pixel panel or, where appropriate, over the portion of the screen dedicated to the autostereoscopic technique.

[0123] The particularity of the screen according to the invention is that the optical array 11 is configured to allow the display of P viewpoints, and the solid angle spread by these P viewpoints is I times the interpupillary distance, where I represents the number of viewpoints of the autostereoscopic image to be displayed by the screen.

[0124] For example, for a screen with 10 viewpoints (P=10), displaying an image at 2 viewpoints (I=2), the solid angle spread out by these 10 viewpoints is 13 cm, i.e., twice the average interpupillary distance of 6.5 cm at the flat tonal distance of the screen.

[0125] In other words, the particular screen proposed by the inventors is equipped with an optical array 11 for displaying P viewpoints. The innovation is that only I different images are displayed on this screen, each replicated a certain number of times. On either side of each sub-pixel magnified by the eye lens are multiple sub-pixels belonging to the same image. Therefore, a sub-pixel, framed by its peer, no longer interferes with the sub-pixel of the other eye. If it interferes with its neighbors, it cannot be seen.

[0126] In the specific case of a screen with 10 viewpoints intended to display autostereoscopic images in 2 viewpoints, as already proposed by the applicant, the manufacture of an optical array with 10 viewpoints continuously visible in a lobe of 13 cm requires a focal length of microlenses 5 times longer than that required for a lobe of 65 cm (65 cm / 13 cm=5). Long focal length lenses have a proportionally larger radius of curvature and are easier to process.

[0127] The processing of long focal length optical components enables an almost perfect surface state to be obtained after processing and bonding of the front side with optical silicone. Furthermore, the defects inherent in the screens of the prior art are greatly reduced by the screens according to the invention.

[0128] A person skilled in the art will be able to determine the parameters of the optical array required to allow the P viewpoint to be displayed with a lobe of I x 6.5 cm, depending on the target flat tone distance and the characteristics of the screen.

[0129] For example, for a 15.6-inch 4K panel, the display area is about 345mm×194mm, and each pixel is 0.09mm, the array pitch is about 0.299mm, and the focal length of the lens array depends on the usage conditions, and for a flat tone of 1.30m (in the case of 10 viewpoints, the image is displayed at 2 viewpoints), the focal length can be 4mm

[0130] 6.1. Example I=2; P=10; N=5; M=5; α=18.43°; vertical sub-pixel

[0131] Figure 2 An embodiment of the present invention is shown, representing a 10-viewpoint screen for displaying a 2-viewpoint autostereoscopic image. The pixel block consists of vertical sub-pixels, and the optical array has a tilt of 18.43° relative to the vertical direction (in other words, I=2; P=10; N=5; M=5; α=18.43°).

[0132] The screen is designed to display 5 times as many image viewpoints in each lobe as are dedicated to the viewer's left eye and 5 times as many image viewpoints as are dedicated to the viewer's right eye. In this figure and all figures involving 2-viewpoint autostereoscopic images, the sub-pixels allocated to the right eye are represented in grey, and the sub-pixels allocated to the left eye are represented in white.

[0133] Furthermore, the black frame implements the minimum "modulus", that is, the smallest block of necessary and sufficient data, which makes it possible to fill the entire screen by periodic repetition, with or without vertical and / or horizontal phase shift. The "modulus" usually applies to a single lens, but this is not always the case, depending on the angle of the array and the number of viewpoints.

[0134] Each pixel of the pixel block consists of sub-pixels of different colors, identified in the figure by the letters R, G and B (for red, green and blue). Each sub-pixel displays a sub-pixel from the left image perspective (white sub-pixel) or from the right image perspective (gray sub-pixel).

[0135] Each pixel consists of an RGB triplet, Figure 3 Different gray levels and the letters R, G and B are used to represent schematically. Figure 3 In FIG. 8 , the sub-pixel dedicated to the left eye is covered by the letter G, and the sub-pixel dedicated to the right eye is covered by the letter D.

[0136] In this embodiment, the angle of the optical array is 18.43°, its tangent is 1 / 3, and the pixels are square, and the optical axis of the lens will shift by one-third of a pixel for each new row of pixels on the screen. At 10 viewpoints, the spacing of the array is about 10 / 3 pixels.

[0137] Viewpoints 1 to 5 are dedicated to the right image, and viewpoints 6 to 10 are dedicated to the left image. Due to this particular arrangement, viewpoints 3 and 8 have 2 buffered viewpoints on each side that show the same image and there is no visible change to the perceived image through them.

[0138] Preferably, the screen is used with a device for tracking the user's head so that it can be ensured that viewpoints 3 and 8 are addressed to the viewer's viewpoints.

[0139] Therefore, the viewpoint perceived by each eye ( Figure 3 Indicated by circles, and Figure 2 The 4 viewpoints are separated by 4 other viewpoints (which act as a buffer for the 6.5 cm interpupillary distance), or by 3 or 5 other viewpoints when the interpupillary distance is lower or higher.

[0140] 6.2. Example I=2; P=9; N=5; M=5; α=18.43°; vertical sub-pixel

[0141] Figure 4 Another embodiment of the invention is shown, representing a screen with 9 viewpoints for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of vertical sub-pixels and the optical array has a tilt of 18.43° relative to the vertical (in other words, I=2; P=9; N=5; M=4; α=18.43°).

[0142] In this embodiment, in the case where an odd number of screen viewpoints are available, the distribution of viewpoints is unbalanced. In the example shown, we choose to allocate 5 viewpoints to the left eye (given by Figure 4 ), and assigns 4 viewpoints to the right eye (represented by the white sub-pixels in Figure 4 ). Of course, another viewpoint distribution could be chosen for essentially the same result. Depending on the direction the user is moving, the distribution could be rebalanced. We prefer eyes that move towards the center of the lobe to have more viewpoints between the two eyes.

[0143] In this embodiment, viewpoints 1 to 5 are dedicated to the right image, and viewpoints 6 to 9 are dedicated to the left image. Viewpoints 3 and 7 are screen viewpoints projected toward the viewer's eyes, with 3 buffered viewpoints between the viewer's eyes.

[0144] 6.3. Example I=2; P=8; N=5; M=5; α=18.43°; vertical sub-pixel

[0145] Figure 5 Another embodiment of the invention is shown, representing an 8-viewpoint screen for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of vertical sub-pixels, and the optical array has a tilt of 18.43° relative to the vertical direction (in other words, I=2; P=8; N=4; M=4; α=18.43°).

[0146] In this embodiment, viewpoints 1 to 4 are dedicated to the right image (in grey), and viewpoints 5 to 8 are dedicated to the left image (in white). Viewpoints 3 and 7 are the screen viewpoints projected towards the viewer's eyes, with 3 buffered viewpoints between the viewer's eyes.

[0147] Of course, other configurations than those shown are possible in terms of the number of screen viewpoints and the inclination of the lens array.

[0148] 6.4. Example I=2; P=10; N=5; M=5; α=9.46°; vertical sub-pixel

[0149] Figure 6 Another embodiment of the invention is shown, representing a screen with 10 viewpoints for displaying autostereoscopic images with 2 viewpoints thereon. The pixel blocks consist of vertical sub-pixels and the optical array has a tilt of 9.46° relative to the vertical (in other words, I=2; P=10; N=5; M=5; α=9.46°).

[0150] It is related to Figure 2 The difference in the embodiment in is the angle of the optical array, which means that the fill grid of the viewpoints is adapted to this particular arrangement, and the spacing of the lenses is twice as fine. The viewpoints are inverted, which has the effect of spreading the "module" out over 6 lines instead of 2.

[0151] 6.5. Example I=2; P=10; N=5; M=5; α=26.56°; vertical sub-pixel

[0152] Figure 7 Another embodiment of the invention is shown, representing a screen with 10 viewpoints for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of vertical sub-pixels and the optical array has an inclination of 26.56° to the vertical (in other words, I=2; P=10; N=5; M=5; α=26.56°).

[0153] Due to the different angles of the optical array, it is Figure 2 Unlike the embodiment in FIG. 1 , the optical array involves a viewpoint-filling grid adapted to this particular arrangement, but the spacing of the lenses is the same. On the other hand, the "module" is spread over three lenses instead of just one. Therefore, Figure 7 The three lenses are shown.

[0154] 6.6. Example I=2; P=10; N=5; M=5; α=33.69°; vertical sub-pixel

[0155] Figure 8 Another embodiment of the invention is shown, representing a screen with 10 viewpoints for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of vertical sub-pixels and the optical array has an inclination of 33.69° to the vertical (in other words, I=2; P=10; N=5; M=5; α=33.69°).

[0156] In addition, relative to Figure 4 In the embodiments shown, the only difference is the angle of the optical array, which means that the viewpoint filling grid is applicable to this particular arrangement.

[0157] 6.7. Example I=2; P=10; N=5; M=5; α=18.43°; horizontal sub-pixel

[0158] The present invention is also applicable to a pixel block formed by horizontal sub-pixels.

[0159] therefore, Fig. 9 An embodiment of the invention is shown, representing a screen with 10 viewpoints for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of horizontal sub-pixels and the optical array has an inclination of 18.43° with respect to the vertical (in other words, I=2; P=10; N=5; M=5; α=18.43°).

[0160] In this screen, each pixel of the pixel matrix consists of a plurality of sub-pixels of different colors superimposed on each other in the direction of the column and is associated with an optical array formed by cylindrical lenses, the main axis of each cylindrical lens forming an angle of 18.43° with the direction of the column.

[0161] The cylindrical microlenses of the lens array can no longer distinguish colors individually, and they simultaneously amplify the three RGB components of each pixel. The entire pixel then becomes the smallest entity that the lens can observe individually through the magnification effect.

[0162] Furthermore, the three color dots that make up each pixel are assembled to form a square. In other words, according to this variant, the color dots fit into three juxtaposed and superimposed small rectangles whose width is three times the height to form a square, i.e., a pixel.

[0163] exist Fig. 9 It can be clearly observed in FIG. 1 that the horizontal sub-pixels are divided into three blocks, each block showing the same viewpoint of the image dedicated to the left eye (shown in white) or dedicated to the right eye (shown in gray).

[0164] For the version with horizontal sub-pixels, views 1 to 5 are dedicated to the right image, and views 6 to 10 are dedicated to the left image.

[0165] 6.8. Example I=2; P=6; N=3; M=3; α=26.56°; horizontal sub-pixel

[0166] Fig.10 An embodiment of the invention is shown, representing a 6-viewpoint screen for displaying autostereoscopic images with 2 viewpoints. The pixel blocks consist of horizontal sub-pixels, and the optical array has a tilt of 26.56° relative to the vertical direction (in other words, I=2; P=6; N=3; M=3; α=26.56°).

[0167] In this embodiment, each viewpoint addressed to each eye of the observer is composed of 2 buffered viewpoints on either side of the viewpoint.

[0168] 6.9. Example I=2; P=10; N=5; M=5; α=33.69°; horizontal sub-pixel

[0169] Fig.11 An embodiment of the present invention is shown, representing a 10-viewpoint screen for displaying a 2-viewpoint autostereoscopic image. The pixel block consists of horizontal sub-pixels, and the optical array has a 33.69° tilt to the vertical (in other words, I=2; P=10; N=5; M=5; α=33.69°).

[0170] In addition, relative to Fig. 9 In the embodiments shown, the only difference is the angle of the optical array, which means that the viewpoint filling grid is applicable to this particular arrangement.

[0171] Of course, other configurations than those shown are possible in terms of the number of screen viewpoints and the inclination of the lens array.

[0172] Please note, Fig. 9 , Fig.10 and Fig.11 The embodiments in can also be applied to IPS panels (acronym for “In-Plane Switching”), organic light-emitting diode panels (OLED) or active-matrix panels with organic light-emitting diodes (AMOLED).

[0173] Indeed, panels with anisotropic pixels, like screens whose pixels consist of a plurality of sub-pixels of different colors superimposed on each other in the direction of the columns, can benefit from the invention to obtain near-perfect resolving power, preventing the optical axis of the lens from intersecting adjacent pixels and generating ghost images.

[0174] 6.10. Example I=4; P=20; α=9.46°; vertical sub-pixel

[0175] Fig.12 Another embodiment of the invention is shown, representing a 20-viewpoint screen for displaying a 4-viewpoint autostereoscopic image. The pixel blocks are formed of vertical sub-pixels, and the optical array has a tilt of 9.46° relative to the vertical direction (in other words, I=4; P=20; α=9.46°).

[0176] It is related to Figure 6 The embodiment in is fundamentally different, because the number of image viewpoints here is equal to 4 instead of 2, which means a suitable grid for filling the viewpoints. In this case, the spacing of the lenses is twice as large.

[0177] In this figure and Fig.13 In the figure, the four image viewpoints are represented by white sub-pixels, gray sub-pixels, vertical shadow sub-pixels and black sub-pixels respectively.

[0178] exist Fig.12 In the embodiment, screen viewpoints 1 to 5 display a first image viewpoint (gray sub-pixels), screen viewpoints 6 to 10 display image viewpoints (shadow sub-pixels), screen viewpoints 11 to 15 display a third image viewpoint (black sub-pixels), and screen viewpoints 16 to 20 display a fourth image viewpoint (white sub-pixels).

[0179] The lenses shown in the figure make it possible to project a stereoscopic viewpoint pair 3-8; 8-13 or 13-18 towards the observer depending on his position, the viewpoints visible to the observer being separated from each other by 4 buffered viewpoints. Each viewpoint visible to the observer is well framed by at least 2 screen viewpoints showing the same image viewpoint.

[0180] Regardless of the number of image viewpoints, the number of screen viewpoints is such that 2 buffered viewpoints can be maintained on either side of each viewpoint addressed to the viewer's eyes. In other words, each image viewpoint extends over 5 consecutive sub-pixels. Therefore, it can be considered that for each image viewpoint, M=5 and N=5.

[0181] 6.11. Example I=4; P=20; N=5; M=5; α=18.43°; vertical sub-pixel

[0182] Fig.13 Another embodiment of the present invention is shown, showing a 20-viewpoint screen for displaying a 4-viewpoint autostereoscopic image. The pixel block is composed of vertical sub-pixels, and the optical array has an inclination of 18.43° relative to the vertical direction (in other words, I=4; P=20; N=5; M=5; α=18.43°).

[0183] It is related to Figure 2 The embodiment in is fundamentally different, because the number of image viewpoints here is equal to 4 instead of 2, which means that the appropriate viewpoints fill the grid. In this case, the spacing of the lenses is twice as large.

[0184] Fig.14 is a schematic diagram of a device for displaying an autostereoscopic image with two viewpoints according to an embodiment of the present invention.

[0185] Such a device is formed by a display screen 12 according to the invention, a display module 13 configured to display right and left images according to the configuration described previously, and a detection device 14 for detecting at each moment the position of the head of the observer 8 relative to the horizontal direction, so as to allow the display module to drag the image viewpoints in each lobe in such a way that the viewpoint screen view visible to the observer is permanently framed by the buffered viewpoints of the image viewpoints visible to that eye.

[0186] The tracking device 14 may be of any known type. For example, it may be an Intel SR300" (SDK1 Gold). This is a time-of-flight RGBD camera with an optimized face tracking library.

[0187] According to one variant, the detection device is configured to detect at each instant the position of the observer's head relative to a predetermined point of the display screen, so that the observer's coordinates X, Y, Z can be defined with a predetermined accuracy in an orthogonal reference system, the predetermined point of the screen of the orthogonal reference system being the origin of the system, the screen defining the X-axis and Y-axis of the system, and the direction perpendicular to the screen defining the Z-axis of the system.

[0188] As mentioned previously, this variant makes it possible in particular to use the screen according to the invention in augmented reality applications, for example for simulation or head-up display applications in cars. In fact, augmented reality requires a significant contrast. Black elements are transparent, while white elements are the most material. If it is desired to display a white square on a transparent background, all possible causes of ghost images that would interfere with the perceived image must be eliminated.

[0189] However, the device according to the invention combining a screen according to the invention and a face tracking device makes it possible to obtain almost perfect resolution capabilities and can therefore be applied in augmented reality applications.

[0190] The invention is not limited to the described embodiments. In particular, and as specified, various screens can be made to obtain an autostereoscopic device with almost perfect resolution. The invention makes it possible to overturn the relief experience as we know it. The usual rules of relief scene composition are obsolete, and all stereoscopic content can be displayed with an unparalleled sense of relief.

[0191] Although the convergence / accommodation separation persists, it's easier to get used to the degradation in brightness and color without any optical noise in the stereo pair, and without the clutter of 3D glasses or headphones.

[0192] Due to its unparalleled resolving power and the superior amplitude of relief that can be exploited, the screen of the invention makes it possible to respond to a very large number of usage requirements that existing equipment can rarely or not meet at all.

[0193] The invention opens up countless market prospects for personal autostereoscopic applications in a large number of technical fields, including: medical imaging, surgical robots, video conferencing, automotive, education, vending machines, remote monitoring, remote operation, drone piloting, aeronautics, cartography, seismology and geological exploration, mining and petroleum, scientific research at all scales from microscopes to satellites, simulation, relief film production lines, CAD, design, machinery, architecture, virtual tourism, museums, games, phones / tablets, entertainment, etc.

[0194] A particularly interesting use case of augmented reality involves specific application environments where the background of the scene does not consist of physical decorations, but rather a display on a screen or through a projector of a 2D image, which is synchronized with the scene and represents the background.

[0195] The autostereoscopic screen according to the invention makes it possible to display very large autostereoscopic images, for example 20 meters deep, which occupy all the physical space separating the screen according to the invention from the background 2D image. Beyond about 20 meters, the eye can hardly perceive the parallax, and monocular cues (such as perspective) become dominant. The 2D background, if it incorporates strong visual cues such as perspective, can therefore perfectly complement the illusion and help to increase the audience's sense of immersion.

[0196] Such a device is primarily single user (especially when using autostereoscopic images with 2 viewpoints), but can be used by multiple users positioned at flat tonal distances due to the superior quality of the filling of the two sub-parts of the lobe.

Claims

1. An autostereoscopic display screen having P viewpoints called screen viewpoints, P being an integer greater than or equal to 6, intended to display autostereoscopic images at I viewpoints called image viewpoints, I being an integer greater than or equal to 2 and less than or equal to P / 3, the screen comprising: A matrix of pixels arranged in rows and columns, each pixel is composed of multiple sub-pixels of different colors, each sub-pixel is used to display a sub-pixel of one of the image viewpoints, An array of cylindrical microlenses, called an optical array, or parallax barrier, is configured to allow a predetermined pair of viewpoints of the screen to be projected toward the eyes of an observer located at a nominal distance from the screen, called the flat tonal distance, The screen is characterized in that the optical array is configured so that P viewpoints of the screen can be perceived continuously by the observer in a direction called the horizontal direction in the space in front of the screen called lobes at the flat tone distance, each lobe covering I times the average interpupillary distance of the observer, and so that the screen viewpoints of each pair of visible viewpoints of the observer at the flat tone distance are separated by at least T viewpoints called buffer viewpoints, T being greater than or equal to 2, so that each of the I image viewpoints can be displayed continuously for each lobe, each repeated P / I times, and each viewpoint visible to the observer at the flat tone distance can be surrounded by at least 2 buffer viewpoints, each buffer viewpoint displaying such an identical image viewpoint.

2. The display screen according to claim 1, characterized in that: I is equal to 2, and the optical array is configured to be able to display M times the image viewpoint dedicated to the left eye of the observer and N times the image viewpoint dedicated to the right eye of the observer in each lobe, M and N are each greater than or equal to 3, and their sum is equal to P, and by forming T buffer viewpoints between the viewpoint dedicated to the left eye and the viewpoint dedicated to the right eye.

3. The display screen according to claim 2, characterized in that: M and N are odd numbers so that each image viewpoint dedicated to each eye of the observer can be surrounded by the same number of buffered viewpoints in each lobe.

4. The display screen according to claim 2, characterized in that: M and N are equal so that the screen allows a symmetrical display of viewpoints dedicated respectively to the left eye and to the right eye of the observer.

5. The display screen according to claim 2, characterized in that: P is equal to 10, so that the screen has 10 viewpoints, and the optical array is configured so that the pairs visible to the observer at the flat tonal distance are views 1-6, 2-7, 3-8, 4-9, 5-10 numbered consecutively from 1 to 10 for viewpoints, so that each sub-pixel perceived by each eye of the observer can be surrounded by 2 buffered viewpoints on each side.

6. The display screen according to claim 1, characterized in that: The optical array is formed by cylindrical lenses, each cylindrical lens having a major axis forming an angle α with the direction of the columns.

7. The display screen according to claim 6, characterized in that: The angle α is between 0° and 45°.

8. The display screen according to claim 7, characterized in that: The angle α is selected from the group consisting of angles of 9.46°, 18.43°, 26.56° and 33.69°.

9. The display screen according to claim 1, characterized in that: Each pixel of the pixel matrix is ​​composed of a plurality of horizontal sub-pixels of different colors superimposed on each other in a column direction.

10. The display screen according to claim 1, characterized in that: Each pixel of the pixel matrix is ​​composed of a plurality of vertical sub-pixels of different colors arranged side by side on a direction line.

11. An apparatus for displaying an autostereoscopic image at I viewpoints, called image viewpoints, comprising: The display screen includes: A matrix of pixels arranged in rows and columns, each pixel is composed of multiple sub-pixels of different colors, each sub-pixel is used to display a sub-pixel of one of the image viewpoints, An array of cylindrical microlenses, called an optical array, or parallax barrier, is configured to allow a predetermined pair of viewpoints of the screen to be projected toward the eyes of an observer located at a nominal distance from the screen, called the flat tonal distance, The screen is characterized in that the optical array is configured so that P viewpoints of the screen can be perceived by the observer continuously in a direction called the horizontal direction in a space in front of the screen called lobes at the flat tonal distance, each lobe covering I times the average interpupillary distance of the observer, and so that the screen viewpoints of each pair of viewpoints visible to the observer at the flat tonal distance are separated by at least T viewpoints called buffer viewpoints, T being greater than or equal to 2, so that each of the I image viewpoints can be displayed continuously for each lobe, each repeated P / I times, and each viewpoint visible to the observer at the flat tonal distance can be surrounded by at least 2 buffer viewpoints, each buffer viewpoint displaying such an identical image viewpoint, and A display module configured to display each of the I image viewpoints for each lobe, each repeated P / I times, each viewpoint visible to the observer at the flat tone distance being framed into at least 2 buffer viewpoints, each buffer viewpoint displaying such same image viewpoint.

12. The display device according to claim 11, characterized in that I is equal to 2, and the display module is configured to display M-fold image viewpoints dedicated to the observer's left eye and N-fold viewpoint images dedicated to the observer's right eye in each lobe formed by the display screen, and form T viewpoints called buffer viewpoints between the image viewpoint dedicated to the left eye and the image viewpoint dedicated to the right eye.

13. The display device according to claim 12, characterized in that Also included is a detection device for detecting the position of the observer's head relative to the horizontal and / or vertical directions at any moment in time so as to allow the display module to slide the image viewpoint in each lobe so that the screen viewpoint visible to the observer is permanently framed by the buffered viewpoint from the image viewpoint visible to the eye.

14. The display device according to claim 13, characterized in that The detection device is configured to detect the position of the observer's head relative to a predetermined point of the display screen at each moment, so that the observer's coordinates X, Y, and Z can be defined with a predetermined accuracy. In the orthogonal reference system in which the predetermined point of the screen is the origin of the orthogonal reference system, the screen defines the X-axis and Y-axis of the system, and the direction perpendicular to the screen defines the Z-axis of the system.

15. A method for displaying autostereoscopic images at I viewpoints at P viewpoints called screen viewpoints on a display screen, P being an integer greater than or equal to 6 and greater than or equal to 3I, I being an integer greater than or equal to 2, the display screen comprising: A matrix of pixels arranged in rows and in columns, each pixel consisting of a plurality of sub-pixels of different colors, each sub-pixel intended to display a sub-pixel of one of the image viewpoints, and an array of cylindrical micro-lenses or parallax barriers, the array being configured to allow the projection of a pair of viewpoints of the display screen towards the eyes of an observer located at a nominal distance from the screen called the flat tonal distance, and to enable P viewpoints of the screen to be perceived successively by the observer in a direction called the horizontal direction at the flat tonal distance in a space in front of the screen called a lobe, each lobe covering I times the average interpupillary distance of the observer, characterised in that it comprises, for each lobe, allocating a copy of the image viewpoint to each adjacent screen viewpoint of each image viewpoint visible to the observer at the flat tonal distance, so that in each lobe, each of the I image viewpoints visible to the observer at the flat tonal distance is flanked by at least 2 buffer viewpoints, each buffer viewpoint displaying the same image viewpoint and consisting of I consecutive image viewpoints each repeated P / I times.

16. The display method according to claim 15, characterized in that: I is equal to 2, and for each lobe, the method comprises: - assigning image viewpoints dedicated to the left eye of the observer to the first M screen viewpoints, - assigning the image viewpoint dedicated to the right eye of the observer to the subsequent N screen viewpoints, M and N are each greater than or equal to 3 and their sum is equal to P.

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