WO2007101637A1

WO2007101637A1 - Three-dimensional representation method and system

Info

Publication number: WO2007101637A1
Application number: PCT/EP2007/001861
Authority: WO
Inventors: Christian Wegwerth; Thomas BRÜGGERT; Markus Klippstein; Stephan Otte; Jürgen Schwarz; Ferenc Toma
Original assignee: Newsight Gmbh
Priority date: 2006-03-07
Filing date: 2007-03-05
Publication date: 2007-09-13
Also published as: TW200801586A; DE102006010970A1

Abstract

The invention relates to a method and a system for three-dimensionally representing a scene for one or more viewers. According to said method, a plurality of views of the scene is displayed on a direction-selective projection screen (4), every view being displayed on the direction-selective projection screen in a direction of display different from the directions of display of the other views. Depending on the directions of display, the direction-selective projection screen defines directions of propagation for the light emitted by the screen into a viewing space. This is done in such a manner that a viewer (5) is presented with different numbers of views for the left and the right eye, thereby producing a three-dimensional effect. The views are displayed on the projection screen (4) by producing one by one images of the views with the help of an image-producing array of individually controlled optical elements - for example a DMD (1) - and displaying them on the projection screen (4).

Description

Method and arrangement for spatial representation

The invention relates to a method for the spatial representation of a scene for one or more observers, in which a plurality of views of the scene are imaged onto a directionally selective projection screen, wherein each of the views in the one imaging direction, which is different from the imaging directions for the other views, on the direction-selective projection screen is mapped, and by the direction-selective projection screen for light emitted from this in a viewing space light propagation directions depending on the imaging directions are given so that a viewer with the left and right eye perceives each different sets of views, so that a spatial impression arises.

The invention further relates to an arrangement for spatially displaying a scene for one or more observers, comprising a directionally selective projection screen onto which several views of the scene are imaged, each of the views being in an imaging direction different from the imaging directions for the other views. is imaged on the directionally selective projection screen, and wherein by the directionally selective projection screen for this emitted in a viewing space light propagation directions depending on the imaging directions are given, so that a viewer with the left and right eye perceives different sets of views, so that a spatial impression arises, also comprising an image-forming array of individually controllableπ optical elements, as well as a lighting device that illuminates the array with light. The set is not empty, ie it contains at least one view; but it can also contain more than one view. It is only important that the quantities are not identical. Even views with differently perceived light intensities can be included in the quantities.

The invention relates to the problem that. In the prior art, the brightness of autostereoscopic screens is generally lower than their counterparts for two-dimensional representation. This is especially true when it comes to screens that can be switched between autostoscopic and two-dimensional display. In this case, the switching from one to the other mode leads to a clearly perceivable difference in brightness. As a rule, the autostereoscopic display is darker. Such arrangements are described, for example, in WO 2004/057878 and PCT / EP20000 / O09405, both owned by the Applicant.

The device disclosed in US 5,132,839 is also associated with a similar disadvantage. Here, an arrangement is described which uses a normal 2D screen for illumination and images its light through a lens or lenticular onto a light modulator. The 2D screen is in the focus of the lens or lenses of the lenticular. The views are sequentially generated on the light modulator, which is an LCD array. Along with this, the lighting is varied, so that for each view, the light - which leaves the lens in the form of parallel rays - comes from another direction. The light passes through the LCD array without changing its direction but is modulated by it. So not the whole 2D-Bildschlrm can be used for lighting, but only a very small part of it. In operation, when the lighting and the views are varied very rapidly to avoid flickering on the screen, this is noticeable on the one hand by a diminished brightness, on the other hand by the fact that each view uses only a small part of the screen. An observer therefore does not see a fully resolved spatial image. Again, a two-dimensional Darstellweise would be possible by a single view is shown on the screen and all elements of the 2D Bιldschirms would emit light. Brightness and resolution would be higher in this case.

Instead of producing the images with a light modulator, it is also possible to use projectors which cast the image of a view-possibly via an imaging optics-onto a direction-selective projection screen. The directionally selective projection screen then specifies the directions of propagation as a function of the angles of incidence of the light. If you use several projectors set up in a circular arc around the projection screen, each of which produces the image of another view, each image is displayed in full resolution on the projection screen. The resolution for the viewer increases considerably. Such an arrangement is described for example in WO 2004/008779 of the applicant. Due to the embodiment of the directionally selective projection screen described therein, however, switching between a 3D representation and a 2D representation is inconvenient to impossible. In addition, the design with a high number of precisely aligned projectors is very complicated and requires a lot of space

Based on this prior art, the object of the invention is therefore to provide a method and an arrangement for spatial representation, with which a high resolution and a high brightness can be achieved, in particular when switching from the 2D in the 3D rendering should not suffer losses in brightness and resolution. The arrangement should also be characterized by a compact design, the largest unit of the screen is.

This object is achieved in a method of the type described above in that the views are projected onto the projection screen by successively generating images of the views with an image-generating array of individually controllable optical elements and imaged onto the projection screen. Compared with the prior art described in WO 2004/008779, in which all images are simultaneously imaged on the projection screen, according to the invention one arrives at a projection apparatus or an image-generating array.

The imaging array itself can generate the views without being illuminated. However, this is very expensive. Preferably, therefore, the imaging array is irradiated with light. Each image is then generated by modifying the light through the optical elements. The modified light is emitted in each case by the array and imaged in the imaging direction of the respective view onto the projection screen.

In order to map the views from the different imaging directions on the Projektioπs- screen, there are now several options. A first possibility is to illuminate the array successively, preferably alternately periodically, from different illumination directions, each illumination direction defining an imaging direction. According to the illumination direction, the modified light is then emitted in a corresponding emission direction. If, for example, a transparent imaging array is used, the illumination direction and emission direction are identical. Depending on the type of imaging optics used, the illumination direction can also correspond to the imaging direction Another possibility is to illuminate the array from one direction with light and to radiate the modified light sequentially, preferably alternately periodically, in different emission directions. Each emission direction in turn provides an imaging device. For example, this can be achieved with a bi-directional array whose optical elements can be switched so that they reflect the light in different directions.

Finally, a third possibility is to illuminate the array from one direction, the modified light also being emitted in one direction only. The modified light must then be transmitted to the projection screen via imaging optics with which the imaging directions are alternated one after the other, preferably periodically be imaged. This can be achieved, for example, by dividing the light, after it has been emitted by the image-forming array, into different beam quantities, for example by means of switchable mirrors, or other switchable beam splitters on an electro- or acousto-optic basis. This split occurs synchronously with the view change. - '

In all cases care must be taken that the frequency of the presentation does not lead to a flickering perception. A complete run of all views with all the images to be generated should therefore preferably take place in a period of at most 1/16 s.

Also for the modification of the light there are different possibilities. One possibility is to generate the images of the views by the optical elements of the array to modulate the light and thus change its brightness or intensity. The optical elements are driven so that they change their transparency or reflectivity. The modulation can be carried out preferably temporally, for example by optical elements that can be switched back and forth only between fully transparent / reflective and not transparent / reflective switched at such a high frequency that different brightness levels are generated for the light to be emitted.

In particular, in such a case, it is preferable to additionally vary the color of the light in the illumination for each imaging direction. Accordingly, for example, a separate image of each view is generated for each base color. Alternatively, it is also possible to generate the images of the views by the optical elements of the array changing the spectrum of the light. For example, they can themselves be provided with color filters in the form of thin layers. Included here is also a change in the brightness between dark (no color of the spectrum) and light (all colors of the spectrum).

Finally, in a further embodiment of the method, a light modulation can take place in that the optical elements modify the polarization of the light, as is the case, for example, when using LC displays.

In a particularly preferred embodiment of the invention, identical views are used. In this way, a viewer creates a two-dimensional impression. This can optionally be done, i. It can be switched between two-dimensional and three-dimensional representation. There is no loss of brightness, and the resolution of all views remains the same. The process is also sufficiently snowy! to switch without noticeable delay.

The views of picture elements are expediently combined with picture information, wherein the optical elements of the array are assigned to picture elements of the respective view to be imaged and to modify the light as a function of the picture information of the picture element. Thus, if the views are composed of pixels, each optical element corresponds to a pixel in a view.

The object is further achieved for an arrangement of the type described above in that a Ansteuseiπrichtung is provided which controls the array and the rest of the arrangement so that successively images of the views are generated with the image-forming array by the light through the optical elements accordingly the respective current view - ie according to the view in the temporal sequence to be displayed at the respective time - is modified, and the modified light is imaged in the imaging direction of the respective view on the projection screen. The Ansteuseiπrichtung therefore ensures on the one hand that according to a predetermined view, an image is generated on or with the image-forming array; on the other hand, it ensures that the image is also displayed on the projection screen according to the imaging direction associated with the particular view. The image of the modified light can be realized in various ways. In one preferred embodiment of the invention, the illumination device has means for illuminating the array from different illumination directions. Each illumination direction is an imaging device. The control device controls the illumination device so that the array is periodically illuminated and is generated periodically are synchronized by the driving device

In a first variant of this embodiment, a stroboscopically switchable lamp is provided for each illumination direction in the illumination device for alternately periodic illumination. These lamps then emit light along the illumination direction onto the image-generating array. The light is modified by the array and either according to the respective illumination direction By means of a corresponding imaging optics is then to ensure that the emitted light from the array is imaged according to the respective, predetermined by the Beleuchtungsπchtung Abbildungsπchtung on the projection screen. Instead of stroboscopically switchable lamps, the lamps can also be provided with diaphragms that are in synchronized short distances controlled by the Ansteuerungseinπchtung open and close Furthermore, instead of lamps and fast switching, high-performance LED arrays can be used

Alternatively, a single light source can also be provided, the light of which is then divided into a separate illumination beam path for each illumination direction, the division being able to take place, for example, by means of switchable diaphragms, acousto-optic transmission filters, partially or semi-transmissive mirrors, etc.

In a second variant of this embodiment of the invention, a rotatably mounted polygon mirror is provided in the illumination device, which deflects light from a light source to a fixed Polygonhohlspiegel, the mirror surfaces of the polygon mirror light along the illumination directions to the array of optical elements reflect the polygonal surfaces are Preferably, but may also be curved The polygon mirror may be formed, for example in the form of a wheel, which is not round, but has a plurality of surfaces by the rotation of the polygon mirror light from a light source, which meets the polygon mirror on the The polygonal hollow mirror, the mirror surfaces can also be flat, is shaped so that each of its surfaces, the light along one of the Be leuchtungsπchtungen that dictate the Abbilduπgsπchtungen on d The image-generating array thus directs the light only from one direction, ie from a mirror surface the polygon hollow mirror comes, either the lamp is stroboscopically switched, or there are switchable diaphragms are used, which can be arranged either in front of the polygon mirror, between polygon mirror and Polygonhohlspiegel, or in the beam path behind the Polygonhohlspiegel and before the image-forming array.

In a further embodiment of the invention, the imaging directions are not predetermined by different illumination directions, but instead the array has means for emitting the modified light in different emission directions. Each emission direction predetermines an imaging direction. The drive device controls the array so that the array alternately radiates the modified light periodically in the different emission directions. The image-forming array itself is thus designed in this case so that it can radiate the light in different directions. This can be done for example with the help of mirrors that can be switched to multiple positions.

In a further embodiment of the invention finally a controllable imaging optics is provided, with which the imaging directions are periodically alternated. The division into the different imaging direction is thus effected here only after leaving the image-producing array. This can be done with similar means as the above-described change of Beleuchtuπgsrichtung. Compared to an array that emits light in different directions, this design is simpler in its construction.

The period should be at most 1 / 16s, to make sure that the display does not flicker for the viewer.

As an imaging array, for example, an array of micromirrors, a so-called Digital Micromirrar Device (DMD), as offered by the company Texas Instruments, Inc. is suitable. It is an array of fast switching mirrors, each of which can be switched to a on and an off state. In the on state it reflects the light, in the off state the light is not reflected. This switching between on and off state takes place so fast that up to 1 024 brightness gradations can be generated for incident light. In this way can be with a DMD alone already create a Craustufenbild a view. It is therefore expedient to provide means for varying the color of the illumination light in the illumination device. These may be, for example, color wheels or colored lamps, which are synchronized by the control device accordingly. The DMD is fast enough for each of the three basic color red, green and blue to produce a corresponding grayscale image in a correspondingly short time. In an embodiment in which the array emits the light in different directions, the micromirrors of the DMD can also be designed so that they are different angles in the on state depending on the view to be displayed - for example, the angles 1 1 ° , 1 1, 5 DEG, ..., 14.5 DEG -, so that the modified light is emitted in different emission directions.

Instead of a DMD, a ferroelectric LC display (FLCD) is provided in another embodiment of the invention as an image-forming array. According to the given imaging direction, the associated view is displayed in full resolution on the FLCD. Other fast switchable LC dispayers can also be used. Similar to the DMD, there are also on and off states. In the on state, the optical element of the FLCD is traπsmissiv in the off state, it allows no light through. In this way, a grayscale image can also be generated. Again, one or more wheels with color filters or colorful lamps can be provided as means for varying the color of the illumination light. Of course, DMDs or FLCDs are also conceivable in which the optical elements, i. the mirrors or pixels are constructed in such a way that they only reflect or transmit certain colors from the outset. In this case, for example, an optical element may comprise three likewise switchable sub-elements for an RGB display, which reflect or transmit light only in the colors red, green or blue.

Finally, instead of a DMD or a FLCD, a fast-switching LCOS chip (liquid-crystal-on-silicon chip) can also be used.

So that the light is imaged on the projection screen, a number of projection optics with projecting lenses are preferably provided corresponding to the number of imaging directions.

As a directionally selective projection screen, a holographic-optical projection screen is preferably provided. The images of the views are usually displayed in the same size on the projection screen, which is located in the image plane. The views are superimposed. Due to the directions and phases of the incident light, the projection screen specifies the propagation directions of the light. Particularly preferably, the holographic Projektioπsschirm is formed as a one-piece holographic-optical element (HOE) on the basis of diffraction gratings. The viewer therefore sees a virtual image, the real image corresponds to the diffraction image point Such integral holographic optical elements can be Such emustrous holographic optical elements can nowadays be covered over a large area and very thinly with a high-density grid network, which can also vary. Such HOE acts quasi-continuously and can represent views in a wide variety of resolutions, for example the resolutions 800 × 600, 1024 x 768 and 1 920 x 1 200 Naturally, HOE is also conceivable for currently customary designs for holographic projection screens, for example based on cylindrical lenses. Also, reflective HOEs can be used

Since an HOE, as described above, images or projects the different colors at different distances from the screen, it is expedient to provide optical correction devices for correcting a color-length error of the holo-graphic projection screen. These can be integrated, for example, in the imaging optics

In a further embodiment, the projection screen is also actively designed so that it specifies different Lichtausbreitungsπchtungen for the temporally succession imaged on him views

The image-generating array can also emit the modified light directly onto a polygon mirror, which then images the light onto the projection screen from different directions via a corresponding imaging optics

The invention will be explained in more detail below with reference to exemplary embodiments in the accompanying drawings

Figure 1 shows a first embodiment of the invention with a DMD chip, which is illuminated from under different directions, ig 2 a second embodiment of the invention, in which is used to divide light on ver different lighting directions a polygon piegel, ig 3 a third execution of Invention, which differs from the first embodiment in that a FLCD is used instead of the DMD chip, ig 4 a modification of the third embodiment, ig another modification of the third embodiment, ig 6 a third modification of the third embodiment, and 7 shows a possibility of the wavelength-selective splitting of the beam path for the correction of the color slant error of a holographic projection screen In the first embodiment of the invention shown in Fig.l is used as the image-forming array of individually controllable optical elements, a DMD (digital micromirror device) 1, as offered by the company Texas Instruments, Inc. To illuminate the DMD 1 arranged on a circular arc stroboscopic switchable lamps 2 are provided. In order to create a stereoscopic view, at least two lamps 2 must be provided, there may be more. A limitation of the number of lamps or representable views is given only by the demand for spatially compact design. Therefore, eight views are preferably represented by eight lamps. The stroboscopically switchable lamps 2 are switched by a control device (not shown) in such a way that only one of them illuminates the DMD 1 at a time. Preferably, they are switched periodically one after the other. Instead of stroboscopically switchable lamps 2, it is also possible to provide rapidly switchable diaphragms, the lamps then emitting light permanently

Each lamp 2 indicates a central illumination direction corresponding to the optical axis, from which the DMD 1 is illuminated. The light is emitted by the DMD 1 and imaged via an imaging optics, which is exemplified here by mirror 3, onto a directionally selective projection screen 4, which in the present example is designed to be transmissive as a one-piece holographic-optical element (HOE) on the basis of diffraction gratings. An equivalent reflective design is also possible. In the plan view of the arrangement shown in Fig.l the figure is shown by way of example for the two outer lamps 2. The light of the left of the two lamps 2 is imaged on the projection screen 4 according to the solid lines. The light of the right of the two lamps 2 is imaged onto the projection screen 4 in accordance with the dot-dash lines. The light is in each case reflected by the DMD 1 and the mirrors 3, so that each illumination direction directly defines an imaging direction.

The views are displayed on the DMD 1 over the entire surface. Each view is therefore the whole DMD 1 available, accordingly, it is displayed over a large area in full resolution on the projection screen 4. Typically, the view is resolved to pixels, and the resolution can be chosen to match the number of optical elements of the imaging array. A pixel of the view therefore corresponds to the DMD 1, an optical element which is designed as a tilting mirror. Since only the brightness of the irradiated light is varied with the DMD 1 and so only a Craustufenbild can be generated, it is useful - not shown here - color wheels with color filters to produce, for example, images of different views for the three primary colors red, green and blue each The three images of a view are then modulated in brightness. In this case, the lamps 2 and the color wheels can be controlled such that the three images of one view are first generated by rotating the color wheel before the next view is generated, or such that each color, one after another, produces the images of all the views. In the latter case, it is enough to have π. ^r n single Farbrdd, weicπes be arranged between the lamps 2 and the DMD J can Since the DMD 1 is very small, it is magnified visually to the viewer 5, so that a sensible viewer Big results

The projection screen 4 is located in the image plane of the image of the enlarged image. By means of the directionally selective projection screen 4, the images of the views reproduced on the projection screen 4 are made visible to a viewer 5, which is located in front of the projection screen 4. If a holographic image is used Projection screen based on diffraction gratings, the viewer sees 5 a virtual image Each view can be, for example, in a strip that has a width that corresponds approximately to the interpupillary distance In this way, each eye of the viewer is 5 different views and it creates a spatial impression

Alternatively, instead of a plurality of different views, the same appearance may be used for each imaging direction. In this case, a viewer sees a two-dimensionally resolved image having the same brightness and resolution as the spatial image except for the impression of spatial depth Thus, a viewer perceives no difference The switching between see two-dimensional and three-dimensionally perceptible operation can ma nuell or electronically by the Ansteuungsanπchtung done, depending on the available Blildlnformationen

2, another embodiment of the invention is shown, which also has a DMD 1 as an imaging array, but grouted over another illumination device In the embodiment shown in Figure 2, the light comes to illuminate the DMD 1 from a single light source 6 via a lighting optics 7, a rotating polygon mirror 8 is illuminated The polygon mirror 8 is rotatably mounted on a rotation axis 9 and rotates in operation in the example along the direction of rotation shown by the arrow The light which strikes the polygon mirror 8 is reflected by this on a Polygonhohlspiegel 10 The Mirror surfaces of polygon mirror 8 and polygon hollow mirror 10 are each configured in a planar manner, but, if this should be technically necessary, can also be configured differently. Due to the rotation of the polygon mirror 8, the light beam reflected from this sweeps over the whole Polygonhohlspiegel 10 In order to exclude that the DMD 1 is illuminated from two different directions simultaneously, the illumination optics 7 expedient switchable diaphragms are also nen instead of a single light source. 6 Alternatively, a color wheel with a plurality of color filters can be provided in the lighting unit 7, which are correspondingly rotated in the beam path. The DMD 1, the polygon mirror 8, as well as the switchable Apertures in the illumination optical system 7 are thereby synchronized by an activation electrode, not shown, in such a way that, when generating the images belonging to a view, the DMD 1 is always illuminated from only one illumination direction. The DMD 1 modifies the light as above described and ray From a mirror 3, the light corresponding to the imaging direction given by the illumination direction is reflected by one of several lenses 1 1. For each imaging device there is an associated lens, which is the one on the DMD! The number of lenses corresponds to the number of views shown corresponding lenses can also be used in the first Ausfuhruπgsbeispiel to Fig 1 Also in the example shown here can be left without brightness or Auflosungsverluste switch between a mode of operation for two-dimensional or three-dimensional perceptual ren representation

A third exemplary embodiment is shown in FIG. 3. This example is structurally similar to the example shown in FIG. 1, but instead of the reflective DMD 1, a transmissive, snowing! Switchable LC Dιsρlay, in the example, a FLCD (ferro- lectrical liquid crystal dispiay) 12 used on the FLCD 12 stroboscopically light is radiated from the lamps 2 from different directions According to the clock of the lamps 2 is now on the FLCD 12 an image of the associated View displayed in full view Each individual optical element of the FLCD 12 is switched between the states transmissive and non-transmissive with a given frequency, so that the corresponding image is generated. Again, color wheels can be used to produce differently colored illumination light Another possibility then there is to provide the individual optical elements with color filters The light that passes through the FLCD 12 is directed to mirror 3 according to the illumination and Bildπchtung from where it is displayed on the projection screen For this purpose, an imaging optics vorgese hen, the in the present case Piel, however, is not shown A further embodiment of the invention is shown in FIG. Here, an LC display 13 is arranged as an image-forming array directly behind the directionally selective projection screen 4. By means of the control electronics, not shown, the individual views are displayed in high-frequency time-resolved on the LC display l 3. In synchronization with this, light sources 14 are switched on and off, so that the light only comes from one of the light sources 14 for each view. The light sources may be stroboscopically switchable and controllable lamps, or also light sources provided with switchable diaphragms. Other means for optically splitting a light source on different illumination beam paths are conceivable. Since the LC display 13 is arranged directly behind the directionally selective projection screen 4, the example illustrated in FIG. 4 is particularly suitable for smaller imaging systems, while the embodiments described above are also suitable for large-format projections.

In a modification of the embodiment described in FIG. 4, as in the example shown in FIG. 5, a lens array 15 with a punctiform light source 16, which is moved rapidly horizontally behind the lens array, can also be used. The lens array 1 5 may consist of both normal lenses and cylindrical lenses, or may be formed as an additional holographic optical element. The light source can also be designed as a stroboscopic lamp, it can also be provided with a shutter to prevent light during the movement of the lamp by two lenses is simultaneously displayed on the LCD display 13, if only one view to see there should be. From the LC display 1 3, the light is changed in color and brightness and transmitted according to the direction of illumination. Corresponding to the emission direction from the LC display 1 3, the light impinges on the projection screen 4, where the exit directions are predetermined as a function of the directions of incidence.

A third modification of the arrangement shown in FIG. 4 is shown in FIG. In contrast to the arrangements shown in FIGS. 4 and S, a backlight 1 7 customary for LCD displays is used here for illumination. The loss of light which is emitted by the backlight 1 7 can be minimized by means of a brightness-enhancing film (BEF) 18. As a brightness-enhancing film 1 8, for example, a prismatic film is suitable. By using the film 18, the light is directed forward and strikes substantially only one direction on a light modulator 19. This can be designed as an electro-optical or acousto-optical element, which depends on Such a light modulator 19 may comprise, for example, elements on a membrane basis, wherein the membrane is deflected more or less depending on the applied voltage and thus the light beam is deflected stronger or weaker than both reflexive and also transmissive membranes are ri ^p nkba ^r The durc ¹ ! the light modulator 1 9 passing light then enters from a certain direction, which is associated with the respective view, on a πchtungsselektiv projection screen 4 This forms the light through the LC display 1 3 through into the corresponding eye of a viewer 5 on the LC display. 1 3, according to the predetermined by the light modulator 1 9 illumination direction, which in turn provides an imaging direction, the Abbilduπgsπchtung associated view shown in the example shown in Figure 6, the projection screen 4 from the viewing direction of the viewer 5 behind the LC display 1 3 He can In both cases, however, a simple switching from a three-dimensional to a two-dimensional representation is possible by the light modulator 19 being switched off. As a result, the directionally selective projection screen 4 loses its effect. Another possibility then exists for each illumination device to represent the same view

If a holographic-optical element (HOE) is used as the direction-selective projection screen 4, the representation of autostereoscopic impressions due to the wavelength dependence of the diffraction at the brongene of the HOE results in wavelength-dependent viewing spaces and thus in the misrepresentation of views and colors In the case of correction, care is taken that several wavelengths from different distances are projected onto the projection screen 4, so that they are imaged into a uniform distance and thus the viewing distances are mapped For each wavelength, in principle, a separate correction mechanism was required, which is however too expensive. In the correction device shown in FIG. 7, the white light emitted by an illuminated imager 20 is subtracted is irradiated, first by means of two color divider 21, which may be configured as splitter mirrors and / or splitter prisms decomposed into the primary colors red, crun and blue If white light comes from the imager 20, the light may instead of dividing into individual colors in wavelength ranges If the images for red, blue and blue are generated one after the other, then the color splitters can be made narrow-banded. Depending on the wavelength or wavelength range, the light beams travel through paths of different lengths, which can be achieved, for example, by mirrors 22 If the illumination in the three primary colors red, crun and blue is separated, so instead of fixed Tei learning, mirrors or Teilerpnsmen also switchable divider or switchable color filters In addition to the Zn sammentuhrung the rays can also be omitted, each color image can be mapped from a different position or distance on the projection screen

Claims

Patent claims

Method for the spatial representation of a scene for one or more viewers (5), in which several views of the scene are displayed on a direction-selective projection screen (4), each of the views in an imaging mode that is different from the imaging modes for the other views, is imaged on the direction-selective projection screen (4), directions of propagation are specified by the direction-selective projection screen (4) for light emitted from it into a viewing space depending on the imaging directions, so that an observer (5) with the left and right eyes each perceives different sets of views, so that a spatial impression is created, characterized in that the views are imaged on the projection screen (4) by successively generating images of the views with an image-generating array of individually controllable optical elements and onto the projection screen (4 ) are shown

Method according to claim 1, characterized in that the image-generating array is irradiated with light, each image is generated by modifying the light by the optical elements, and the modified light is emitted by the array and in the imaging direction of the respective view onto the projection screen

Method according to one of the preceding claims, characterized in that the array is alternately periodically illuminated from different lighting directions, each lighting direction specifying an imaging direction

4 Method according to claim 1 or 2, characterized in that the array is illuminated with light from one direction and the modified light is alternately emitted periodically in different radiation directions, each radiation direction specifying an imaging direction.

5. The method according to claim 1 or 2, characterized in that the array is illuminated from one direction and the modified light is radiated in one direction, the modified light being directed onto the projection screen (4.) via imaging optics with which the imaging directions are periodically alternated ) is shown.

6. The method according to one of claims 3 to 5, characterized in that a value of at most 1/16 s is selected as the period.

7. Method according to one of the preceding claims, characterized in that the images of the views are generated by the optical elements of the array modulating the light and thus changing its brightness.

8. Method according to one of the preceding claims, characterized in that the color of the light is varied for each imaging direction during the illumination.

9. The method according to any one of claims T to 7, characterized in that the optical elements of the array change the spectrum of the light

10. The method according to any one of claims 7 to 9, characterized in that the optical elements modify the polarization of the light.

1 1 Method according to one of the preceding claims, characterized in that identical views are optionally used, which creates a two-dimensional impression for a viewer.

12. The method according to one of the preceding claims, characterized in that the views are composed of image elements with image information, the optical elements of the array being image elements of the respective image. be assigned to the view to be formed and modify the light depending on the image information of the image element.

13. Arrangement for the spatial representation of a scene for one or more viewers (S), comprising a direction-selective projection screen (4) on which several views of the scene are imaged, each of the views in an imaging direction that is different from the imaging directions for the other views is different, is imaged on the direction-selective projection screen (4), and propagation directions are specified by the direction-selective projection screen (4) for light emitted from it into a viewing space depending on the imaging directions, so that a viewer (5) with the left and right eye perceives different sets of views, so that a spatial impression is created, an image-generating array of individually controllable optical elements, an illumination device that illuminates the array with light, characterized in that a control device is provided that illuminates the array and the rest The arrangement is controlled in such a way that images of the views are generated one after the other with the image-generating array by modifying the light through the optical elements according to the current view, and the modified light is imaged on the projection screen (4) in the imaging direction of the respective view.

14. Arrangement according to claim 13, characterized in that the lighting device has means for illuminating the array from different lighting directions, each lighting direction specifying an imaging direction, and the control device controls the lighting device in such a way that the array is alternately illuminated periodically.

5. Arrangement according to claim 14, characterized in that in the lighting device a stroboscopically switchable lamp (2) is provided for each lighting direction.

6 Arrangement according to claim 14, characterized in that a light source is provided for the lighting arrangement and a separate lighting beam path with a switchable aperture is provided for each lighting direction.

1 7 Arrangement according to claim 16, characterized in that partially transparent mirrors are provided for division into several illumination beam paths.

1 8 Arrangement according to claim M ₁ , characterized in that a rotatably mounted polygonal mirror (8) is provided in the lighting device, which deflects light from a light source (6) onto a fixed polygonal hollow mirror (10), the mirror surfaces of the polygonal hollow mirror reflecting the light along the Reflect lighting directions onto the array of optical elements.

19 Arrangement according to claim 18, characterized in that the mirror surfaces of the polygon mirror (8) and polygon hollow mirror (1 0) are flat.

20. Arrangement according to claim 13, characterized in that the array has means for emitting the modified light in different radiation directions, each radiation direction specifying an imaging direction, and wherein the control device controls the array in such a way that the array periodically alternates the modified light into the radiates in different directions.

1 . Arrangement according to claim 13, characterized in that controllable imaging optics are provided with which the imaging directions are periodically alternated.

2 Arrangement according to one of claims 13 to 21, characterized in that an array of micromirrors (1) is provided as the image-generating array.

Arrangement according to one of claims 13 to 21, characterized in that a ferroelectric LC display (1 2) is provided as an array of optical elements

Arrangement according to one of claims 13 to 23, characterized in that means for varying the color of the illuminating light are provided in the lighting device.

25. Arrangement according to claim 24, characterized in that one or more wheels with color filters are provided as means for varying the color of the illuminating light.

26. Arrangement according to one of claims i 3 to 1 5, characterized in that a number of projection optics with projection lenses corresponding to the number of imaging directions are provided for imaging on the projection screen (4).

27. Arrangement according to one of claims 13 to 26, characterized in that a holographic-optical projection screen is provided as the direction-selective projection screen (4).

28. Arrangement according to claim 27, characterized in that the holographic-optical projection screen is designed as a one-piece holographic optical element (HOE) based on diffraction gratings.

9 Arrangement according to claim 27 or 28, characterized in that optical correction devices are provided for correcting a longitudinal chromatic aberration of the holographic projection screen.