WO2012034708A1 - Methods and arrangement for optional two- or three-dimensional representation - Google Patents

Abstract

The invention relates to the field of three-dimensional representation, more specifically representation that can be perceived three-dimensionally without aids, wherein a changeover to a customary 2D mode is intended to be possible. It encompasses methods and arrangements. Methods according to the invention comprise the following steps: simultaneous and/or temporally sequential visualization of at least n=2 views A(k) where k=1,..., n of the stated scene on a grid (1) composed of pixels x(i, j) in lines i and columns j, permanent predetermination of light propagation directions for the light emitted or transmitted by the pixels x(i, j) by means of a transmissive first optical element (2a), with the result that one or more observers (3), from a multiplicity of viewing positions in front of the grid (1) composed of pixels x(i, j), permanently or/and on average over time, in each case sees or see with one eye exclusively or predominantly a first selection from the views A(k) and with the other eye exclusively or predominantly a second selection from the views A(k), with the result that a three-dimensional visual impression arises, wherein, for an optional two-dimensionally perceptible representation, a second optical element (2b), which is structurally identical to the first optical element (2a), is placed onto the first optical element (2a) in a manner rotated by 180°, as a result of which the permanent predetermination of light propagation directions is cancelled by a majority.

Description

 Method and arrangement for optionally two- or three-dimensional representation

The invention relates to the field of three-dimensional representation, in particular the three-dimensionally perceptible presentation without tools, wherein a switch to a normal 2D mode should be possible.

The prior art knows various methods of the aforementioned type. Thus, JP 08-331605 (Masutani Takeshi et al) teaches a distribution of views on the RGB Farbsubpixel, before it is a structured barrier (step barrier). The disadvantage here is the high loss of resolution, since per view only one nth of the existing pixels on the imager (with N the number of views shown) is perceived monocular. US 4,829,365 (Eichenlaub) proposes a structured backlight with light valve (shutter) and mask for 3D presentation. Again, the full (intrinsic resolution) of the imager is not achieved.

US Pat. No. 5,036,385 (Oak Leaves) describes a structured backlight with temporally offset blinking times in conjunction with a light valve (shutter). Again, the full (intrinsic) resolution of the imager is not achieved here.

In document EP 1662808 a double LCD barrier is presented. The disadvantage here is that no full resolution for the 3D representation is achieved. In addition, the 3D channel separation is not complete if the viewer is not exactly in certain positions. Furthermore, the aforementioned optical jump occurs.

Furthermore, DE 42281 11 C1 (Sombrowsky) describes a device known by the term Holotron. A component for stereoscopic reproduction with a dynamic imager is used. This system is coupled with a very fast camera, which complicates the implementation.

1

CONFIRMATION COPY DE 4123895 (Runge / Just) again proposes a system for dynamic 3D image reproduction with high resolution. Also, this system is coupled with a very fast camera to even produce 3D images.

Finally, US 2001/028356 (Balogh) teaches picture elements which radiate different picture information in different spatial directions. The implementation of this technical teaching is very complex.

US 6,985,296 (Lipton) teaches the use of an ID 2D mask for a lenticular screen for 2D-3D switching. The same is deformable and takes on the lenticular shape when pressed, so that a certain 2D representation is possible. The disadvantage here is the high pressure required to produce the most complete compensation of the lenticular effect.

Finally, WO 2007003792 teaches a 2D-3D switchable arrangement with a first lenticular for the 3D display and a second, complementarily structured lenticular, which can be varied in its distance from the first lenticular to switch between 2D and 3D. The disadvantage here is in particular the need for a complementary, that is to say inversely formed, lenticular. Thus, the same optical component can not always be produced in the manufacturing process, but two different shapes are needed. Moreover, the positioning and distance adjustment of the two optics to each other must be carried out with high precision for the 3D impression. Against this background of the prior art, the invention is based on the object of specifying method and arrangement of the type mentioned, which for 3D representations that offer a reduced in the resolution image, with simple, inexpensive means switching to a possible high-resolution 2D mode allowed.

D

This object is achieved according to the invention by a method for selectively two- or three-dimensional representation of a scene, comprising the following steps simultaneous and / or temporally sequential visualization of at least n = 2 views A (k) with k = 1, ..., n of said scene on a grid of picture elements x (i, j) in lines i and columns j,

 permanent specification of light propagation directions for the light emitted or transmitted by the 5 picture elements x (i, j) by means of a transmissive first optical element,

 so that one or more observers of a plurality of viewing positions in front of the grid of picture elements x (i, j) permanently or / and on average each with an eye exclusively or I0 predominantly a first selection from the views A (k) and with the see or see another eye exclusively or predominantly a second selection from the views A (k), so that a three-dimensional visual impression is created,

 wherein, for an optionally two-dimensionally perceptible representation, a second optical element, which is identical in construction to the first optical element, is placed rotated by 180 degrees onto the first optical element, whereby the permanent presetting of light propagation directions is canceled by a majority.

 In other words, the effect of the first optical element, which enables the 3D-0 representation, is essentially canceled out by a second optical element which is to be applied temporarily and arranged in a phase-shifted manner.

 The particular advantage of this is that both optical elements are identical in construction and thus inexpensive to produce in series. In this case, the simultaneous and / or temporally sequential arrangement of the partial image information of different views A (k) on the grid (1) of pixels x (i, j) preferably takes place in a two-dimensional periodic pattern.

The optical elements (2a, 2b) preferably include lenticular, prismatic grids, D microlens arrays and / or more preferably so-called CLD elements.

The latter are described in more detail in the unpublished documents of the applicants 10 2009 054 706.1 and 10 2009 019 762.1. The corresponding optical structures, such as cylindrical lenses, microlenses, prisms, convex / concave structures with diaphragms, can be arranged on the respective optical element in periodic or non-periodic patterns, inclined or not inclined relative to the vertical or also arranged in free form. The emergence of a spatial impression with a corresponding representation of views A (k) is well known in the art.

 5

 Further, the picture elements x (i, j) preferably correspond to color subpixels (R, G or B) or clusters of color subpixels (e.g., RG or GB) or full color pixels.

The object of the invention is also achieved by an ID arrangement according to the invention for the optional two- or three-dimensional representation of a scene, comprising

 - An image display device with pixels x (i, j) in rows i and columns j on which concurrently and / or temporally sequentially at least n = 2 views A (k) with k = 1, ..., n of said scene made visible become

15,

 a first transmissive optical element arranged in front of the image reproduction device for permanently specifying light propagation directions for the light emitted or transmitted by the picture elements x (i, j),

G - allowing one or more viewers of a variety of

 Viewing positions in front of the grid of picture elements x (i, j) permanently and / or temporally with one eye exclusively or predominantly a first selection from the views A (k) and with the other eye exclusively or predominantly a second selection from the5 views A (k) sees or sees, so that a three-dimensional visual impression is created, as well

 a second optical element, which is identical to the first optical element, and which is placed on the first optical element rotated for an optional two-dimensionally perceptible representation by 180 degrees, whereby the permanent specification of

 Lichtausbreitungsrichtungen majority is repealed.

Again, the optical elements preferably include lenticular, prismatic, microlens, and / or CLD elements. The corresponding Optical structures such as cylindrical lenses, microlenses, prisms, convex / concave structures with diaphragms can be arranged on the respective optical element in periodic or non-periodic patterns, inclined or not inclined relative to the vertical, or even in free form.

 5

 Further, the picture elements x (i, j) correspond to color subpixels (R, G or B) or clusters of color subpixels (e.g., RG or GB) or full color pixels.

The image display device (1) may be a color LCD screen, a plasma ID display, a projection screen, an LED based screen, FED screen, an SED screen, or a VFD screen. Other embodiments are possible.

A further, special embodiment of the invention comprises the arrangement for the optional two- or three-dimensional representation of a scene

 a picture display device with picture elements x (i, j) in lines i and columns j, on which simultaneously and / or temporally sequentially at least n = 2 views A (k) with k = 1, ..., n of said scene are made visible can,

0 - a first transmissive optical element disposed in front of the image display device,

 a second optical element which is identical to the first optical element and which is arranged rotated by 180 degrees in front of the first optical element,

5 - wherein the two optical elements can assume at least 2 relative positions to each other,

wherein, in a first relative position, where the vertices of the optical elements are adjacent, the combined optical action of the optical elements allows for specifying light propagation directions for the D emitted or transmitted by the pixels x (i, j) such that one or more Viewer of a plurality of viewing positions in front of the grid of picture elements x (i, j) permanently and / or in the temporal means each with an eye exclusively or predominantly a first selection from the views A (k) and with the see or see another eye exclusively or predominantly a second selection from the views A (k), so that a three-dimensional visual impression is created, and

 - In a second relative position, in which the vertices of the optical elements are each on gap, the combined optical

Effect of the optical elements for a specification of light propagation directions for the emitted or transmitted by the pixels x (i, j) light is canceled by a majority, so that an optional two-dimensional perceptible representation is made possible.

The relative position of the optical elements relative to one another is preferably changed by the displacement in the x, y, and or z direction of at least one of the optical elements (2a, 2b).

 In other words: A combination of two identical optical elements, such as with lens or lenticular components, which are positioned to each other so that the lens strips are aligned in apex position to each other, means that their optical effects just do not compensate, but overlap constructively , If the strip-shaped lenses are thus positioned in the vertex-to-vertex position without lateral offset from one another, then the two directly superposed plano-convex lenses form the light passing through them together acting in the viewer's space. They then act as a two-stage, imaging lens system. This close vertex-to-apex arrangement requires undisturbed effectiveness after a very small air gap, the thickness of which should be comparable to or less than the vertex height of the curved, optically functional surfaces. In the narrowest case, a contact between upper and lower vertices is conceivable.

The optical effect of these lens pairs is needed for the desired 3D visualization. It is based on the tight arrangement of the two plan convex lens strips, which are positioned directly above each other, and without lateral offset to each other. For the desired, optimal 3D viewing distance, therefore, this interaction of the two lens structures must be considered. The corresponding calculation of the radii of curvature or of the focal lengths must take place in such a way that the main planes of the two-stage, imaging lens system enable the required transmission properties into the SD viewer space. Switching from the 3D visualization to the (normal) 2D display is done by very little, lateral displacement of the upper optical element with respect to the underlying. (But also the displacement of the lower opposite the

5 above is conceivable.) It is important that such a transfer has to be made so that it is done just by half the local period, ie by T / 2 (or of course by an odd, integer multiple thereof, ie by nx T / 2, where n = 1, 3, 5, 7, ... is an odd, integer).

 This lateral displacement, which is necessary for the 2D representation, can be based on different

ID way: electrostrictive, magnetostrictive, by means of hydraulic or air pressure, or even purely mechanical.

 Important for all these possibilities is the low-friction and precise mounting of the optical element or the lenticular disk to be displaced, which must work so precisely that the return to the old position is ensured at all times and remains 15. This bearing and guide rail must be play-free and precisely fitting, it must not wear too quickly, and it must be insensitive to temperature changes. Their repeatability must meet the condition Δχ «T / 2 at all times.

ZD If, under special conditions or for special requirements, the air gap between the upper and lower optical filter discs is too large or interfering, then the possibility should be provided of minimizing this air gap by minimizing the distance between laterally offset discs by adjusting the height. At this height adjustability must be the same critical

Claims are made as to their thermo-mechanical structure and their repeatability, as to the lateral displacement devices. For the degree of height adjustment accordingly stricter requirements apply, because the vertex height is in any case much smaller than the lateral location period T.

 30 In this case switching from 3D to 2 D has to be done in two steps:

 Lateral displacement of a filter disk by n × T / 2, where n = 1, 3, 5, 7, ...

 - Height adjustment down to minimize the air gap

Switching from 2D to 3D must then be done in reverse order: - Height adjustment upwards to increase the air gap, until it allows:

 Lateral displacement of the filter disk by n × T / 2, where n = -1, -3, -5, -7, ...

The invention will be explained below with reference to exemplary embodiments. The drawings show:

 Fig. 1 shows the cross section through the surface of an optical element, the

 Prismatic strip is constructed,

Fig. 2 shows the arrangement of two identical optical elements with

 Prismatic strip to compensate for the refractive effect of

Prism faces,

 3 shows the cross section through a lenticular structure as an optical element, consisting of the glass substrate with thereon, strip-shaped cylindrical lenses,

 Fig. 4 shows the cross section through the arrangement of two identical optical

 Elements with lenticular structures (strip-shaped cylindrical lenses) for compensating the refraction at the curved surfaces,

 Fig. 5 shows the cross section through a compensation arrangement of two identical optical elements with strip-shaped cylindrical lenses, and

 Fig. 6 shows the schematic diagram of a further, special embodiment of the invention.

All drawings are not to scale. This applies in particular also, if present, any angular dimensions and distances.

 The following explanations apply equally to the inventive method and the arrangements. For each case, the grid 1 or the picture display device 1 with the picture elements x (i, j) is arranged in a mental manner below the optical element 2a shown at the lower edge of the picture, but has not been shown for redundancy reasons.

 For easier understanding of the inventive concept, it should first be explained on a surface of an optical element 2a, which consists of strip-shaped prisms. Such a surface can be seen in Fig. 1 as a cross section.

The optical effect through the refractive surfaces of the prism strips of the first optical element 2 a, which is used to specify light propagation directions for a three-dimensional perceptible representation is used, can be repealed by a second, identical optical element 2b reversed (that is, rotated by 180 degrees) and thus phase-shifted on the surface of the first optical element 2a directly touches. This arrangement is shown in FIG. 2. It can be seen here that the effect of the two identical optical elements 2a, 2b with prismatic strips compensates for the refractive effect of the prismatic surfaces.

This arrangement of two identical optical elements 2a, 2b to compensate for the prism effect takes into account the same optical material having the same refractive index η (λ) and substantially the same prism shape, so that the air gap resulting from each other due to the phase-shifted alignment is small against the Dimensions of the prisms. With such an arrangement as shown in Fig. 2 results from the interaction of the lower and upper prism structure a "plane-parallel plate" through which the light passing therethrough is not deflected from its direction of propagation. Since plane-parallel plates have a magnification ratio of ß _x = 1 Thus, the transmitted light bundles are neither enlarged nor reduced, the optical effect of the first prismatic lens, that is the first optical element 2a, is compensated .. A 2D representation in (compared to the pure 3D variant with only one optical element 2a) improved resolution becomes achieved what was desired.

It is completely analogous when lenticular structures are used for the two optical elements 2a, 2b. On a substrate strip-like cylindrical lenses are now arranged as optical elements, as shown in Fig. 3.

Fig. 3 shows the cross section through a lenticular structure consisting of the glass substrate with thereon strip-shaped cylindrical lenses.

The optical effect of the strip-shaped cylindrical lenses is based on the refraction of the light passing through at the curved functional surface whose curvature can first be described with a radius r ₂ . Without limiting the generality, all of the above-mentioned considerations on prisms also apply to aspheric functional surfaces (eg parabolic surfaces, or hyperbolic surfaces).

The optical effect of such a manner of arrangement, as shown schematically in FIG. 3, ensures that all the light beams passing through are refracted with the direction of the refracted rays of light depending on the particular location of the refraction on the curved surface. Only such light rays which strike the vertex plane of the curved surfaces perpendicularly, maintain their propagation direction. This mode of operation of an optical element having lenticular structures can be compensated by arranging a second, identical element 2b in reverse and phase-shifted directly over the first element 2a, as shown in FIG.

 There is an exemplary cross section through the arrangement of two identical optical elements 2a, 2b with lenticular structures (strip-shaped cylindrical lenses) to compensate for the refraction of the curved surfaces to see.

Important for the compensation of the effect of an optical element with lenticular structures is adherence to the phase shift. Irrespective of whether the elements are prismatic or cylindrical lenses with spherical or aspherical curvature, they are always periodic optical structures whose spatial frequency depends on the number of images and on the size of the pixels x (i, j). (pixel pitch) depends. In any case, one can represent the period T of such optically active structures, as shown in FIG. 5 using the example of strip-shaped cylindrical lenses. At this period T, the phase shift, which is just π, is measured. Thus, the two identical optical elements 2a, 2b are not arranged mirror-symmetrically (congruent) to each other, they must be just about half the local period, ie shifted by T / 2 each other laterally, because only then you can compensate for the effect of the refractive surfaces observe their phase shift by π. This is shown in greater detail in FIG. 5 in the form of a cross section through a compensation arrangement of two identically constructed, optical elements 2a, 2b with strip-shaped cylindrical lenses. The compensation condition is thus that the lateral displacement of the two optical elements to each other must be just half the spatial period, ie by T / 2. In this position, the refractive effects of the opposing, oppositely curved surfaces compensate each other the optical elements 2a, 2b so that the entire arrangement acts much like a plane-parallel optical disk.

A further advantage of this arrangement according to FIG. 5 is that there are virtually no adjustment problems in the positioning of the second optical element 2b in front of the first optical element 2a, because the opposite curvatures of its optical functional surfaces ensure that these convex parts are correctly positioned in the recesses between the optical structures of the first, lower element 2a "slip." The second optical element 2b centers itself, so to speak.

ID

 In summary, the invention can also be described in other words: A switchable 3D / 2D display is implemented as follows.

 Raster 1 is provided with picture elements x (i, j), e.g. an LC display, on its surface with a corresponding optical element 2a, for example. With a CLD

15 element or a lenticular, for 3D visualization. This element 2a is fixedly mounted on the panel surface (cover glass) according to rules known in the art (for example according to the teaching of PCT / DE2008 / 000925), ie fixed. If you want to suppress the 3D mode of such a screen, then you bring a second, identical optical element 2b, rotated 180 degrees directly

ZG (directly) on the already mounted, first optical element 2a so that its optical structures, in a lenticular thus the strip-shaped lenses, come straight to the lens interstices of the first element 2a. (See again figures 4 and 5). With this second optical element 2b so aligned, the panel can be used for normal 2D operation without

25 that the resolution is limited.

 This positioning of the second, identical element 2b is done safely, but not permanently, for example, by adhesion forces, gravity, magnetic or other forces. It can be taken back at any time in order to be able to perceive 3D-visualized images on the same panel again.

 SD

Fig. 6 shows a further, special embodiment of the invention. Shown is an inventive arrangement for selectively two- or three-dimensional representation of a scene comprising a picture display device 1 with picture elements x (i, j) in lines i and columns j, on which simultaneously and / or temporally sequentially at least n = 2 views A (k) with k = 1, ..., n of said scene made visible can be

 a first transmissive optical element 2a disposed in front of the image display device 1,

 a second optical element 2b, which is identical to the first optical element 2a, and which is arranged rotated 180 degrees before the first optical element 2a,

 wherein the two optical elements 2a, 2b can assume at least 2 relative positions to one another,

 wherein, in a first relative position in which the vertices of the optical elements 2a, 2b are adjacent, the combined optical effect of the optical elements 2a, 2b is a specification of light propagation directions for the light emitted or transmitted by the pixels x (i, j) allows one or more observers 3 from a plurality of viewing positions in front of the grid 1 of picture elements x (i, j) permanently and / or in time each with an eye exclusively or predominantly a first selection from the views A (k) and see or see with the other eye exclusively or predominantly a second selection from the views A (k), so that a three-dimensional visual impression is created, and

 wherein in a second relative position in which the vertices of the optical elements 2a, 2b are each in gap, the combined optical effect of the optical elements 2a, 2b for a specification of light propagation directions for the radiated from the pixels x (i, j) or transmitted light is canceled by a majority, so that an optional two-dimensional perceptible representation is made possible.

The relative position of the optical elements 2a, 2b relative to one another is preferably changed by the displacement in the x, y, and or z direction of at least one of the optical elements 2a, 2b. This can be done via suitable rails, piezoelectric elements, stepper motors and / or other suitable mechanical components. The advantages of the invention are versatile. In particular, arrangements according to the invention offer a possibility for a very inexpensive design of 2D / 3D switchable displays.

 The invention can also be realized technically with simple means. In particular, it only requires the construction of a mold for the optical elements, since they are of identical construction.

Claims

claims A method for selectively displaying a scene in two or three dimensions, comprising the following steps  simultaneous and / or temporally sequential visualization of at least n = 2 views A (k) with k = 1,... n of said scene on a grid (1) of pixels x (ij) in rows i and columns j,  permanent specification of light propagation directions for the light emitted or transmitted by the picture elements x (i, j) by means of a transmissive first optical element (2a),  - So that one or more observers (3) from a plurality of viewing positions in front of the grid (1) from pixels x (i, j) permanently or / temporally each with an eye exclusively or predominantly a first selection from the views A (k) and with the other eye sees or sees exclusively or predominantly a second selection from the views A (k), so that a three-dimensional visual impression is created,  wherein, for an optional two-dimensionally perceptible representation, a second optical element (2b) which is identical in construction to the first optical element (2a) is placed rotated by 180 degrees onto the first optical element (2a), whereby the permanent stipulation of light propagation directions is canceled by a majority , A method according to claim 1, characterized in that the simultaneous and / or temporally sequential arrangement of the image part information of different views A (k) on the grid (1) of picture elements x (i, j) takes place in a two-dimensional periodic pattern. Method according to one of the preceding claims, characterized in that the optical elements (2a, 2b) include lenticular, prismatic grids, microlens arrays and / or CLD elements. Method according to one of the preceding claims, characterized the picture elements x (i, j) correspond to color subpixels (R, G or B) or clusters of color subpixels (eg RG or GB) or full color pixels. 5. Arrangement for optionally two- or three-dimensional representation of a scene, comprising  - An image display device (1) with pixels x (i, j) in rows i and columns j, on which simultaneously and / or temporally sequentially at least n = 2 views A (k) with k = 1, ..., n of said Scene can be made visible  ID - a first transmissive optical element (2a) arranged in front of the image display device (1) for permanently specifying light propagation directions for the light emitted or transmitted by the picture elements x (i, j),  - whereby one or more observers (3) from a plurality of 15 viewing positions in front of the grid (1) of picture elements x (i, j) permanently or / and in time each with an eye exclusively or predominantly a first selection from the views A (k) and with the other eye see or see exclusively or predominantly a second selection from the views A (k), so that a Q three-dimensional visual impression arises, as well  a second optical element (2b) which is identical in construction to the first optical element (2a) and which is placed on the first optical element (2a) rotated by 180 degrees for an optionally two-dimensionally perceptible representation, whereby the permanent presetting of 5 light propagation directions is canceled by a majority becomes. 6. Arrangement according to claim 5, characterized in that the optical elements (2a, 2b) lenticular, prismatic grids, microlens arrays and / or CLD elements include. 0  7. Arrangement according to one of claims 5 or 6, characterized  the pixels x (i, j) correspond to color subpixels (R, G or B) or clusters of color subpixels (e.g., RG or GB) or full color pixels. Arrangement according to one of claims 5 - 7, characterized in that the image display device (1) is a color LCD screen, a plasma display, a projection screen, an LED-based screen, FED screen, an SED screen or a VFD screen. Arrangement for optionally two- or three-dimensional representation of a scene, comprising  a picture display device (1) with picture elements x (i, j) in lines i and columns j, on which simultaneously and / or temporally sequentially at least n = 2 views A (k) with k = 1, ..., n of said scene can be visualized  a first transmissive optical element (2a) arranged in front of the image display device (1),  a second optical element (2b) which is identical to the first optical element (2a) and which is arranged rotated 180 degrees in front of the first optical element (2a),  wherein the two optical elements (2a, 2b) can assume at least 2 relative positions to one another,  - wherein in a first relative position in which the vertices of the optical elements (2a, 2b) are adjacent, the combined optical effect of the optical elements (2a, 2b) is a default of Lichtausbreitungsrichtungen for the emitted from the pixels x (i, j) or transmits transmitted light such that one or more observers (3) from a plurality of viewing positions in front of the grid (1) of pixels x (ij) permanent or / and on average each with an eye exclusively or predominantly a first selection of the Views A (k) and with the other eye exclusively or predominantly a second selection from the views A (k) see or see, so that a three-dimensional visual impression is formed, and wherein, in a second relative position in which the vertices of the optical elements (2a, 2b) are each in gap, the combined optical effect of the optical elements (2a, 2b) for specifying light propagation directions for that of the pixels x (i, j) radiated or transmitted light is canceled by a majority, so that an optional two-dimensional perceptible representation is made possible. 10. Arrangement according to claim 9, characterized in that the relative position of the optical elements (2a, 2b) to each other by the displacement in the x-, y-, and z-direction of at least one of the optical elements (2a, 2b) is changed.