Multiview display device

Abstract

The invention provides an autostereoscopic display device having an adjuster for adjusting the direction of a light beam (5). The adjuster (1) has an off-state and on-state and comprises a stack (10) of layers. The stack (10) comprises a first solid material layer (100) having a first optic axis (111), a second solid material layer (200) having a second optic axis (211), and switchable birefringent twisted nematic liquid crystal material (30) or chiral nematic liquid crystal material. Further, the stack includes a first interface (130) between the first solid material layer (100) and birefringent material (30) and a second interface (230) between the second solid material layer (200) and birefringent material (30). In the off-state, the birefringent material (30) at the first interface (130) is configured to have an optic axis parallel to the first optic axis (111) and the birefringent material (30) at the second interface (230) is configured to have an optic axis parallel to the second optic axis (211). In the on-state, the birefringent material (30) at the first interface (130) is configured to have an optic axis perpendicular to the first optic axis (111) and the birefringent material (30) at the second interface (230) is configured to have an optic axis perpendicular to the second optic axis (211).

Claims

1. A multi-view display comprising: an array of pixels, wherein each pixel emits a light; a first layer disposed on the multi-view display, wherein the first layer has a first optical axis; a second layer, wherein the second layer has a second optical axis; a first switchable birefringent material disposed between the first layer and the second layer, wherein the first birefringent material has a first state and a second state; a second switchable birefringent material disposed between the first switchable birefringent material and the second layer, wherein the second birefringent material has a third state and a fourth state; a first interface between the first layer and the first switchable birefringent material, wherein the first interface defines a first array of lenticular lenses, the first array of lenticular lenses having a first depth; and a second interface between the second layer and the second switchable birefringent material wherein the second interface defines a second array of lenticular lenses, the second array of lenticular lenses having a second depth, wherein in the first state, the first switchable birefringent material is arranged to have a first birefringent optical axis parallel to the first optical axis, wherein in the third state the second switchable birefringent material is arranged to have a second birefringent optical axis parallel to the second optical axis, wherein in the second state, the first switchable birefringent material is arranged to have the first birefringent optical axis perpendicular to the first optical axis, wherein in the fourth state the second switchable birefringent material at the second interface is arranged to have the second birefringent optical axis perpendicular to the second optical axis, wherein a spacing between the first layer and the second layer is less than the first depth and is less than the second depth.

2. The multi-view display of claim 1, wherein the first optical axis and the second optical axis are perpendicular to each other.

3. The multi-view display of claim 1, wherein in the second state the first birefringent axis is arranged to be parallel to the second birefringent optical axis in the fourth state.

4. The multi-view display of claim 1, wherein the light comprises unpolarized light.

5. The multi-view display of claim 1, wherein the pixels comprise organic light emitting diodes.

6. The multi-view display of claim 1, wherein the pixels comprise light emitting diodes.

7. The multi-view display of claim 1, wherein the first state configures the multi-view display as a two-dimensional display, wherein the second state configures multi-view display as a three-dimensional autostereoscopic display.

8. The multi-view display of claim 1, wherein the first state configures the multi-view display device as a single view display, wherein the second state configures the multi-view display device as a multi-view display.

9. The multi-view display of claim 1, wherein the first switchable birefringent material is a twisted nematic liquid crystal material.

10. The multi-view display of claim 1, wherein the first switchable birefringent material is a chiral nematic liquid crystal material.

11. A multi-view display comprising: a display panel, the display panel having pixels, the pixels arranged for generating light beams; and an adjuster, wherein the adjuster is arranged for adjusting a direction of the light beams, wherein the adjuster has an off-state and an on-state, the adjuster comprising: a first layer having a first optical axis; a second layer having a second optical axis; a first switchable birefringent material disposed between the first layer and the second layer, wherein the first birefringent material has a first state and a second state; a second switchable birefringent material disposed between the first switchable birefringent material and the second layer, wherein the second birefringent material has a third state and a fourth state; a first interface between the first layer and the first switchable birefringent material, wherein the first interface defines a first array of lenticular lenses, the first array of lenticular lenses having a first depth; and a second interface between the second layer and the second switchable birefringent material wherein the second interface defines a second array of lenticular lenses, the second array of lenticular lenses having a second depth, wherein the first array of lenticular lenses and the second array of lenticular lenses are arranged to adjust the direction of the light beams, wherein in the off-state, the first switchable birefringent material is configured to have a first switchable birefringent optical axis parallel to the first optical axis, wherein in the off-state and the second switchable birefringent material is configured to have a second switchable birefringent optical axis parallel to the second optical axis; wherein in the on-state, the first switchable birefringent material is configured to have the first switchable birefringent optical axis perpendicular to the first optical axis, wherein in the on-state the second birefringent material is configured to have the second switchable birefringent optical axis perpendicular to the second optical axis.

12. The multi-view display of claim 11, wherein the first optical axis and the second optical axis are perpendicular to each other.

13. The multi-view display of claim 11, wherein in the second state the first switchable birefringent axis is arranged to be parallel to the second switchable birefringent optical axis in the fourth state.

14. The multi-view display of claim 11, wherein the light beams comprises unpolarized light.

15. The multi-view display of claim 11, wherein the pixels comprise organic light emitting diodes.

16. The multi-view display of claim 11, wherein the pixels comprise light emitting diodes.

17. The multi-view display of claim 11, wherein the off-state configures the multi-view display as a two-dimensional display, wherein the on-state configures multi-view display as a three-dimensional autostereoscopic display.

18. The multi-view display of claim 11, wherein the off-state configures the multi-view display device as a single view display, wherein the on-state configures the multi-view display device as a multi-view display.

19. The multi-view display of claim 11, wherein the switchable birefringent material is a twisted nematic liquid crystal material.

20. The multi-view display of claim 11, wherein the switchable birefringent material is a chiral nematic liquid crystal material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

(2) FIG. 1 schematically depicts some principles of the invention;

(3) FIGS. 2a-2b schematically depict an embodiment of the adjuster in the off and on statethis embodiment is used in the display of the invention;

(4) FIGS. 3a-3b schematically depict another embodiment of the adjuster in the off and on state;

(5) FIGS. 4a-4b schematically depict yet another embodiment of the adjuster in the off and on state;

(6) FIGS. 5a-5b schematically depict embodiments of micro-structured interfaces;

(7) FIGS. 6a-6c schematically depict embodiments of optical devices comprising the adjuster;

(8) FIG. 7 is used to explain how a switchable lens arrangement can be used for providing a switchable 2D/3D display;

(9) FIG. 8 shows a first example of optical arrangement used in an autostereoscopic display in the 2D mode;

(10) FIG. 9 shows the optical arrangement of FIG. 8 in the 3D mode;

(11) FIG. 10 shows a first example of optical arrangement of the invention for an autostereoscopic display in the 2D mode;

(12) FIG. 11 shows the optical arrangement of FIG. 10 in the 3D mode;

(13) FIG. 12 shows a second example of optical arrangement of the invention for an autostereoscopic display in the 2D mode; and

(14) FIG. 13 shows the optical arrangement of FIG. 12 in the 3D mode.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(15) Before describing the invention, some designs and uses of optical adjuster as developed (but not yet published) by the applicant will first be described.

(16) FIG. 1 schematically depicts an adjuster 1 for adjusting the direction of a light beam 5. The adjuster 1 comprises a stack 10 of layers. The stack 10 comprises a first solid material layer 100 having a first optic axis (not depicted, see FIGS. 2a-4b), a second solid material layer 200 having a second optic axis (not depicted, see FIGS. 2a-4b), and switchable birefringent material 30. The switchable birefringent material may be arranged in a single layer or in separate layers (see below).

(17) For the sake of understanding, polyimide layers and electrode layers such as ITO layers are not drawn in the Figs. Those features are known to the person skilled in the art. The term adjacent herein may thus in some embodiments mean that between at least part of adjacent items, for instance a polyimide layer and/or (transparent) ITO layer is present.

(18) The stack further comprises a first interface 130 between the first solid material layer 100 and birefringent material 30 and a second interface 230 between the second solid material layer 200 and birefringent material 30.

(19) The materials of the first material layer 100 and the second material layer 200 as well as the switchable birefringent material are selected and configures that (a) in the off-state, the birefringent material 30 at the first interface 130 is configured to have an optic axis parallel to the first optic axis and the birefringent material 30 at the second interface 230 is configured to have an optic axis parallel to the second optic axis; and (2) in the on-state, the birefringent material 30 at the first interface 130 is configured to have an optic axis perpendicular to the first optic axis and the birefringent material 30 at the second interface 230 is configured to have an optic axis perpendicular to the second optic axis.

(20) The first and the second solid material layers 100,200 preferably comprise solid materials that are birefringent. The switchable birefringent material is preferably liquid crystal, such as twisted nematic liquid crystal or chiral nematic liquid crystal.

(21) Especially, the interfaces 130,230 may comprise one or more microstructures (see below). The external faces of the first and the second material layers are however preferably arranged substantially parallel. These faces are preferably planar, whereas the layers at the interfaces 130,230 with the switchable birefringent material are (thus) preferably substantially non-planar and comprise one or more microstructures (see below).

(22) In a specific embodiment, depicted in FIGS. 2a-2b (off-state and on-state, respectively), the stack 10 comprises a stack of the first solid material layer 100, a layer 300 of switchable birefringent material 30, and the second solid material layer 200. The first optic axis, indicated with reference 111, and the second optic axis, indicated with reference 211, are chosen perpendicular. Such adjuster 1 essentially consists of three layers, wherein the first and second solid material layers sandwich the switchable birefringent material. Especially, in such embodiment, the switchable birefringent material 30 comprises twisted nematic liquid crystal material, like such as TL213 from Merck.

(23) The invention involves the use of this type of adjuster within a switchable autostereoscopic display device, as explained further below.

(24) In the off-state, the optic axis (or here optic axes because especially chiral nematic material is applied as switchable birefringent material) of the switchable birefringent material, which optic axis is indicated with reference, 311 at the respective interfaces 130 and 230 are aligned parallel with the optic axes 111 and 211 (of the solid materials at the other side of the respective interfaces). Hence, at the interfaces 130,230 the optic axes are aligned parallel at both sides of the interfaces, respectively. The optic axis of the birefringent material layer may rotate over 90 to obtain the desired configuration of the optic axes in relation to the first and second optic axes 111,211 of the first and second solid materials 100,200.

(25) The layer thickness of the switchable birefringent layer in this embodiment, wherein the birefringent material may comprise twisted nematic LC, may be in the range of about 40-100 m, such as about 50 m. Such thickness may be enough to create a 90, rotation.

(26) When the adjuster 1 is switched on, the alignment of the optic axis of the switchable birefringent material 30 changes, and aligns perpendicular to both the optic axes of the first and second material layers, respectively. Here, the optic axis 311 of the birefringent material, through substantially the entire material, is aligned perpendicular to the optic axes 111,211 of the first and second material layers.

(27) In a further specific embodiment, depicted in FIGS. 3a-3b (off-state and on-state, respectively), the stack 10 comprises a stack 10 of:

(28) a first layer 301 of switchable birefringent material 30;

(29) first solid material layer 100;

(30) a second layer 302 of switchable material 30; and

(31) the second solid material layer 200.

(32) The first layer 301 of switchable birefringent material 30 and the first solid material layer 100 create first interface 130. The second layer 302 of switchable material 30 and the second solid material layer 200 create second interface 230. In fact, this stack 10 comprises 2 cells, i.e. the first layer 301 and the first solid material 100, and the second layer 302 and the second solid material 200. These two cells may be arranged adjacent, i.e. first material 100 and second layer 302 create a further interface 400. This further interface 400 is preferably planar. The optic axis in the respective first and second layers 301,302 of switchable birefringent material 30 are indicated with references 311(1) and 311(2), respectively.

(33) Here, the first optic axis 111 and the second optic axis 211 in this embodiment are perpendicular. The optic axis 311(1) (substantially all over the material of the first layer 301 of switchable birefringent material 30) of the first layer 301 is parallel with the first optic axis 111. The optic axis 311(2) (substantially all over the material of the second layer 302 of switchable birefringent material 30) of the second layer 302 is parallel with the second optic axis 211.

(34) In the off-state, the optic axis 311(1) and 311(2) at the respective interfaces 130 and 230 are thus aligned parallel with the optic axis 111 and 211 of the first solid material layer 100 and the second solid material layer 200, respectively. When the adjuster 1 is switched on, the alignment of the optic axis of the switchable birefringent material 30 changes and aligns perpendicular to both the optic axes of the first and second material layers, respectively, and perpendicular to each other. Referring to FIG. 3b, the optic axis 311(1) of the first layer 301 of switchable birefringent material 30 is perpendicular to the optic axis 111 of the first solid material layer 100 and perpendicular to the optic axis 311(2) of the second layer 302 of switchable birefringent material 30. The optic axis 311(2) of the second layer 302 of switchable birefringent material 30 is perpendicular to the optic axis 211 of the second solid material layer 200 and perpendicular to the optic axis 311(1) of the first layer 301 of switchable birefringent material 30.

(35) In yet a further specific embodiment, depicted in FIGS. 4a-4b (off-state and on-state, respectively), the stack 10 comprises a stack of the first solid material layer 100;

(36) a first layer 301 of switchable birefringent material 30;

(37) an intermediate layer 500 comprising a polarization rotator, such as a twisted nematic cell;

(38) a second layer 302 of switchable material 30; and

(39) the second solid material layer 200.

(40) The first layer 301 of switchable birefringent material 30 and the first solid material layer 100 create first interface 130. The second layer 302 of switchable material 30 and the second solid material layer 200 create second interface 230.

(41) Here, again, two cells are provided, which cells both comprise a switchable birefringent material and a (birefringent) solid material layer. The optic axes (111/311(1) and 211/311(2)) within the individual cells (100/301 and 200/302, respectively) are aligned parallel. Further, all optic axes may be aligned parallel in the off state.

(42) Between the two cells, the polarization rotator 500 is arranged. The cells may sandwich the polarization rotator 500. In a specific embodiment, the first layer 301 of switchable birefringent material 30 creates an interface 501 with the polarization rotator 500. In a further specific embodiment, the second layer 302 of switchable birefringent material 30 creates an interface 502 with the polarization rotator 500.

(43) In the on-state, the direction of the optic axes of the switchable birefringent material 30 changes for both the first layer 301 and the second layer 302. The optic axes 311(1) and 311(2) swap to a perpendicular state relative to the optic axes 111,211 of the solid material layers 100, 200 respectively. Further, they swap to a state wherein they are mutually parallel. Further, they may swap to a state wherein they are substantially perpendicular to the external face (i.e. substantially parallel to a normal to the stack 1).

(44) FIGS. 5a-5b non-limitingly depict some embodiments of microstructures on the interfaces 130 and 230. These microstructures are in FIG. 5a lens-shaped, and in FIG. 5b sawtooth shaped. Note that preferably, the microstructures are one-dimensional. Hence, FIGS. 5a/5b may schematically depict cross-sections of embodiments of stack 10.

(45) In some of the embodiments (see for instance FIGS. 1-3), the change in refractive index for the deflected part of the beam passing the first interface in the on-state is opposite in sign with respect to the change of the refractive index of the deflected part of the beam passing the second interface. When demanding the same action at each interface (redirection in a certain direction or focusing, for instance) then for small differences in index, the shapes of the microstructures may substantially be mirror images. One can, however, induce small differences for obtaining an optimal effect. For the embodiment of FIGS. 4a-4b, preferably the interfaces do not comprise microstructures.

(46) FIGS. 6a-6b schematically depicts embodiments of an optical device 600 comprising the adjuster 1.

(47) The optical device 600 comprises a light source 601 configured to generate a beam of light 5. The optical device 600 further comprises the adjuster 1 for adjusting the direction of a light beam 5. The optical device 600 may be arranged to generate a single beam of light, but may also be configured to generate a plurality of light beams 5.

(48) Here, by way of example, the optical device 600 of FIG. 6a comprises a display device comprising a plurality of pixels 602 as light sources 601. As explained further below, the invention relates specifically to the use of the optical adjuster in an autostereoscopic display device. The adjuster 1 is configured to adjust the directions of the plurality of light beams 5. The plurality of pixels 602 generate the plurality of light beams 5, which may be manipulated by the adjuster 1. In a specific embodiment, the optical device 600 may optionally comprises a plurality of adjusters 1.

(49) In another embodiment, the optical device 600 is an illumination device, see FIG. 6b. Such illumination device may be a lamp, especially a substantially point source lamp, such as a spot light. Hence, in an embodiment, the optical device 600 comprises a spot light as light source 601. Especially, the light source 601 is configured to generate a light beam 5 with an opening angle (2*) selected from the range of 2-20, such as preferably 2-10. The adjusted beam (or adjusted light beam), downstream of the adjuster 1, when the adjuster 1 is switched on, is indicated with reference 5.

(50) FIG. 6c schematically depicts an embodiment of the optical device 600, wherein the device is arranged to detect light. The optical device 600 comprises an optical sensor 651, such as a CCD array, and the adjuster 1 as described herein. The adjuster may be used to redirect light beams 5 in the direction of the optical sensor. For instance, in this way one may scan or sweep areas.

(51) The adjuster described above is for adjusting the direction of a light beam 5. The adjuster 1 has an off-state and on-state and comprises a stack 10 of layers. The stack 10 comprises a first solid material layer 100 having a first optic axis 111, a second solid material layer 200 having a second optic axis 211, and switchable birefringent material 30. Further, the stack includes a first interface 130 between the first solid material layer 100 and birefringent material 30 and a second interface 230 between the second solid material layer 200 and birefringent material 30. In the off-state, the birefringent material 30 at the first interface 130 is configured to have an optic axis parallel to the first optic axis 111 and the birefringent material 30 at the second interface 230 is configured to have an optic axis parallel to the second optic axis 211. In the on-state, the birefringent material 30 at the first interface 130 is configured to have an optic axis perpendicular to the first optic axis 111 and the birefringent material 30 at the second interface 230 is configured to have an optic axis perpendicular to the second optic axis 211. This device may be used to redirect light beams, for instance for spot lights, display devices or optical sensors.

(52) The use of an adjuster has been described above in connection with devices which are used to redirect optical beams such as spot lights or vehicle headlights. The invention relates specifically to the use of this type of adjuster applied to autostereoscopic display devices.

(53) Autostereoscopic displays can be divided in two groups, one for which glasses are required and one for which this is not required. For the latter, the display sends out angle dependent images. The design is made such that the left and the right eye receive different images and a 3D impression is obtained.

(54) Angle dependent images can be obtained from an LCD-TV with a special backlight or with a lenticular attached to the front of the display. The lenticular comprises an array of cylinder lenses, and projects the LC pixel plane to infinity. In such cases, the lenses transform differences in position to differences in angle. This means that only a selection of pixels can be seen from a certain angle. More different views for more angles leads to a better 3D impression. However, besides giving the 3D impression, more views also automatically reduce the resolution that is seen since all available pixels have been divided among the views: more views means less pixels per view. This leads to a trade-off between resolution and the number of views. A detailed description of one way to construct an autostereoscopic device in terms of design of a solid material (non switchable) lenticular array is described in e.g. U.S. Pat. No. 6,064,424, the contents of which are incorporated by reference. Other ways of designing autostereoscopic display may be used.

(55) A resolution loss may be acceptable for showing 3D content but for displaying 2D content (in which all the views are the same) it is often not acceptable. In order to overcome this issue, several so-called 2D/3D switchable displays have been proposed. These have a fixed lenticular structure that is filled up with a birefringent liquid crystal. By switching the liquid crystal, the lenticular can be switched on and off. A more detailed description of the design and operation of such a device is found in e.g. U.S. Pat. No. 6,069,650, the contents of which are incorporated by reference. Especially the way for providing lens function or transparent function of the lenticular in relation to 2D or 3D mode is described in detail. The described switchable principle in the patent may require the light from the display to be polarized e.g. in case a regular LCD panel is used as the display panel. Such LCD panels are known to provide polarized light in general.

(56) The output of an OLED display is basically unpolarized. In order to apply standard switchable lenticulars, a polarizer is needed in the system for removing the light with the wrong polarization. This will reduce the light output by 50%, giving a loss in brightness or a loss in power efficiency.

(57) FIG. 7 shows how the switchable lenticular can control the light paths. The left figure shows no lens action while the right figure shows lens action. The orientation of the LC is different in the two Figs. Since the light is polarized, it will encounter in the left figure the ordinary index of refraction which is matched with the replica. Due to this match, there is no lens action. In the right figure, the light will encounter the extra-ordinary index of refraction which is not matched with the replica, giving a lens action.

(58) A problem with this system is that it can only be used for one polarization of the light, making it unsuited for unpolarized OLED displays.

(59) The light adjuster described above can be used to provide a switchable lens function. The interfaces 130,230 become the lenticular lens surfaces.

(60) FIGS. 8 and 9 show a first example of implementation of a switchable lenticular arrangement suitable for an unpolarized display output (such as an OLED display) and using the light redirection concept explained above.

(61) FIG. 8 shows the system in the 2D mode. This corresponds to the configuration explained with reference to FIG. 2a, but with separate switchable layers 30a, 30b and the two fixed layers 100, 200.

(62) At the curved lens surfaces there is no difference in optical properties of the materials and therefore no lens action. This will give perfect 2D images.

(63) FIG. 9 shows the system in the 3D mode. This corresponds to the configuration explained with reference to FIG. 2b, but again with separate switchable layers 30a, 30b and the two fixed layers 100, 200. The medium in the middle has switched, and the lower layer 200 refracts one of the polarizations while the layer above 100 switches the other polarization.

(64) The result is that even with an unpolarized light input, the lens action can be turned on and off.

(65) FIGS. 10 and 11 show a first example of implementation of a switchable lenticular arrangement in accordance with the invention, suitable for an unpolarized display output (such as an OLED display) and using the light redirection concept explained above.

(66) FIG. 10 shows the system in the 2D mode. This corresponds even more closely to the configuration explained with reference to FIG. 2a, with a single switchable layer 30 and the two fixed layers 100, 200. This implementation is easier to make from a fabrication point of view. In addition there will be less cross talk.

(67) As described above, the single switchable layer 30 is filled with liquid crystal which rotates the polarization over 90 degrees. Since the optical properties are matched at the interface, no lens action will appear. This is the 2D mode.

(68) FIG. 11 shows the system in the 3D mode. Since the liquid crystal is untwisted in the cell, both polarizations will refract.

(69) There are two potential problems with the design of FIGS. 10 and 11. The first is that the thickness of the switchable LC layer is not well controlled in the center of the lens arrangement. This can lead to artefacts in some circumstances. The second problem is that light going through a certain lens-interface at the lower lenticular may go through another lens-interface at the lenticular above that is shifted by one or more lenses. This leads to cross-talk which can be annoying. This is represented by arrow 1100.

(70) In order to address this issue, the lenticulars can be placed very close to each other such that the sides of the lenses almost touch each other. FIGS. 12 and 13 show a second example in accordance with the invention using this concept. In particular, the minimum spacing between the non-switchable lenses is less than the depth of the lens (with reference to FIG. 12, s<d). Preferably, the minimum spacing s is less than the depth of the lenses of both arrays. The lenses of the two arrays typically have the same depth and pitch (as shown) but this is not essential. This reduction in spacing leads to a reduction of cross-talk.

(71) FIG. 12 shows the 2D mode, and FIG. 13 shows the 3D mode.

(72) In order to make this possible, there are some restrictions on the possible combinations of optical materials. Birefringent materials are often specified with n=nEnO, where nE is the extra-ordinary index of refraction and nO is the ordinary index of refraction.

(73) For the embodiment of FIGS. 12 and 13, the ordinary index and the extra ordinary index of refraction of the three materials used (two fixed lenticulars and switchable LC) should all be the same. In addition, for the lens shape shown the n should be negative as well (in order to provide the bending towards the normal in the left part of FIG. 13 for example).

(74) The switching of the liquid crystal can be achieved by combining an alignment layer, suitably positioned electrodes, and suitable type of LC (in particular the property).

(75) Alignment layers can for instance force the LC close to the boundary to orient itself with an angle to the boundary where this angle can for instance be close to zero or 90 degrees. To provide LC alignment along the interface of the lenses, in-plane-switching electrodes can for example be used. These methods are all well-known to those skilled in the art.

(76) The arrangement of layers can be interchanged in the designs above. The two lens arrangements are shown with the same lens pitch, but these may be different. The two fixed lens arrangements can also have different angles if desired. The fixed lenticulars may also be homeotopically aligned

(77) In the arrangement described above, two switchable lenticulars each act on perpendicular polarization components of the incident light. The lenticulars are spaced by a switchable non-isotropic medium and the lenticulars themselves are non-isotropic having corresponding optical refractive index properties as the medium between them. This means that both polarizations can be used making the system efficient.

(78) In the drawings, less relevant features like electrical cables, etc. have not (all) been drawn for the sake of clarity.

(79) In the embodiments described above the adjuster is used to create multiple views in such a way that autostereoscopic viewing is enabled. In one example this may be done by designing the lenticulars such that individual pixels of the display panel are projected into the different views. For the detailed description see the US patents referred to here before and the description of the current invention.

(80) The adjuster of the current invention is however equally well suitable for providing a dual-view display where multiple viewers can observe different 2D content. For example the driver/pilot and co-driver/co-pilot of a vehicle or aircraft may be provided by traffic data and non-traffic data such as movie or other, respectively. A detailed description of such displays is provided in e.g. international application PCT/IB03/03844, the content of which is incorporated by reference. The application provides dual view displays having parallax barriers or having lenticular arrays. Without having to repeat the content of that application, the description of the embodiments that relate to the display having a lenticular array in PCT/IB03/03844 provide examples of how to construct a dual view display in terms of relations of pixel dimensions and lenticular design. In order to arrive at a dual view display of the current invention, the lenticular of the display of PCT/IB03/03844 must be replaced with the adjuster of the current invention where the dimensions of the adjuster lenticulars are to be chosen conform the description for the relevant embodiments of the display of PCT/IB03/03844. Furthermore, the LCD display device may be replaced with a display panel that provides substantially unpolarized light such as e.g. an OLED display panel.

(81) The term substantially herein, such as in substantially flat or in substantially consists, etc., will be understood by the person skilled in the art. In embodiments the adjective substantially may be removed. Where applicable, the term substantially may also include embodiments with entirely, completely, all, etc. Where applicable, the term substantially may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, including 100%. The term comprise includes also embodiments wherein the term comprises means consists of.

(82) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

(83) The devices herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

(84) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb to comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The term and/or includes any and all combinations of one or more of the associated listed items. The article a or an preceding an element does not exclude the presence of a plurality of such elements. The article the preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.