Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/1323—Arrangements for providing a switchable viewing angle
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
  • G02B30/20—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes
  • G02B30/26—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the autostereoscopic type
  • G02B30/30—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the autostereoscopic type involving parallax barriers
  • G02B30/31—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the autostereoscopic type involving parallax barriers involving active parallax barriers
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/1336—Illuminating devices
  • G02F1/133626—Illuminating devices providing two modes of illumination, e.g. day-night

Definitions

• US 2007/030240 A1 describes an optical element for controlling the direction of light propagation of light originating from background lighting.
• This optical element requires, for example, liquid crystals in the form of PDLCs, which on the one hand is expensive, but on the other hand is particularly safety-critical for end customer applications, since PDLC liquid crystals usually require voltages higher than 60V for your circuit.
• CN 1987606 A in turn, a screen is described which makes the viewing angle of a screen controllable by means of two background illuminations.
• first light plate which must be wedge-shaped in order to enable the intended focused light extraction. Exact details for achieving the focused light extraction with corresponding angular conditions are not disclosed.
• US 2018/0267344 A1 describes a structure with two flat lighting modules.
• the light from the lighting module located at the rear in the viewing direction is focused by a separate structure. After focusing, the light has to pass through the front lighting module, which has scattering elements. Thus, a strong light focus for a privacy screen cannot be optimally implemented.
• US 2007/0008456 A1 discloses the division of a light emission angle into at least 3 areas, two areas of which are usually exposed to light. This means that a privacy screen in which a display illuminated in this way is used cannot be viewed from one direction alone.
• the object of the invention to describe a method and an arrangement for influencing the directions of light propagation.
• the method should be inexpensive and suitable for mass production and, in particular, be universally applicable with OLED screens, but also with different screen types, in order to enable switching between a privacy screen and a free viewing mode, the resolution of such a screen being essentially not reduced shall be.
• This object is achieved according to the invention by a method for influencing the directions of light propagation of several adjacent self-luminous and / or illuminated surfaces (F1, F2,...) Which comprise a transparent substrate on the light exit side. In a first alternative, each surface has its own substrate, or — in a second alternative — several or all surfaces (F1, F2,...) Use a common substrate.
• the substrate is arranged above, but not necessarily directly above, the light-generating layer of the self-luminous or illuminated surfaces (F1, F2, ).
• the method according to the invention comprises the following steps: for at least a number of surfaces (F1, F2, ...), arranging switchable absorbers on the light exit side in the first alternative on one or more partial surfaces of the respective substrate or in the second alternative one or more partial areas of the common substrate, the spatial main direction of propagation of these switchable absorbers being parallel to the light exit area of the substrate or substrates, up to a tolerance of a maximum of 10 °,
• a restricted viewing angle does not necessarily mean that no light at all is emitted in certain directions. Rather, a certain amount of residual light can still be emitted there, which, however, prevents comfortable vision.
• Typical values for such residual light (measured as luminance) even in zones intended for restricted visibility are a few percent, usually a maximum of 1% to 5%, of the peak value (which is the maximum true from the dedicated viewing zone of the restricted viewing angle is acceptable).
• each area (F1, F2, ...) has its own substrate (or 1.1, 1 .2, 1 .3 etc.). These substrates are then preferably arranged essentially in one plane.
• all surfaces (F1, F2,...) Comprise a common, two-dimensionally extended substrate.
• a plurality of clusters of surfaces (F1, F2,%) Can each comprise a substrate, in which case a plurality of substrates are then present.
• the common substrate or the individual substrates can be viewed as a transparent spacer, which consists for example of glass or a polymer.
• a substrate can also be an integral component of an image generator, for example the substrate of an OLED pixel or OLED panel, or the substrate of an LCD panel. If, however, a separate substrate, for example an OLED or LCD panel, is already present, then that is the common substrate described in this invention or so are the individual ones Substrates additional optical layers.
• a substrate used in this invention can have thicknesses of a few micrometers to approximately one or a few millimeters, depending on the configuration.
• each individual surface F1, F2, (7) is restricted, for example, by arranging permanent or switchable absorbing layers between - in the first alternative - the individual substrates, or - in the second alternative - within the one common substrate, the planes in which the switchable absorbers and in which the absorbing layers are each arranged preferably standing perpendicular to one another with a tolerance of a maximum of 25 degrees.
• a collimating lens is arranged on each of the partial surfaces of the substrates or the substrate on which no switchable absorber is applied in order to achieve further beam focusing and to enable the viewing angle to be restricted even better .
• Each switchable absorber can comprise, for example, an electrochromic layer and / or a liquid crystal layer and / or a layer based on electrophoresis and / or a layer based on electrowetting with absorbent particles and / or an opaque-transparent switching PDLC layer (“polymer dispersed liquid crysta ), each of which can be controlled by an electric field.
• each switchable absorber comprises a switchable color filter, which in each case absorbs the color spectrum of the color emitted through an area (F1, F2, ...) below in a first state and transmits it in a second state , whereby the switchable color filter can be controlled with respect to its state by an electric field.
• Each switchable absorber preferably has the geometry of a perforated diaphragm. This can, for example, be round, polygonal, in particular rectangular.
• the order of magnitude of the switchable absorbers in relation to their surface area is usually around 25% to 90% self-luminous or illuminated surface (F1, F2, ). In absolute numbers, depending on the design of the surfaces (F1, F2, ...), this will be a few dozen square micrometers to a few square millimeters or even square centimeters. Other configurations are conceivable.
• Geometries of inverse perforated diaphragms are also possible for special configurations of the invention. With such an inverse perforated diaphragm, those partial areas or areas of a substrate are covered with a switchable from sorber compared to a non-inverse perforated diaphragm, which are otherwise not covered, and vice versa.
• the method according to the invention is of particular practical importance when even luminous areas (F1, F2, of the smallest pixels of an OLED, miniLED, VCSEL, QLED, LED or micro-LED screen, so that such a screen is switched between an operating state B1 for a restricted viewing angle and an operating state B2 for an unrestricted viewing angle can be.
• the large number of illuminated or self-illuminating surfaces (F1, F2, ...) together form the said screen.
• the screen technology can generally be self-luminous or illuminated, such as LCD, SED, FED or others.
• LCD liquid crystal display
• FED field emission display
• the same is usually backlit by a light source that can be controlled over a large area.
• direct backlight which enables locally different illuminance levels.
• a cluster of pixels is illuminated by separately controllable LEDs.
• the method according to the invention can also be used here.
• a flat lighting source such as an LCD backlight (direct backlight or fully controllable) is divided into individual areas F1, F2, ... (e.g. vertical stripes, or a two-dimensional grid) or so the end Even luminous or illuminated surfaces F1, F2, ... exist that the process according to the invention can be implemented on it.
• the invention also includes the use of a flat lighting source, which consists of self-luminous or illuminated surfaces (F1, F2, ...) for backlighting an LCD panel, whereby the LCD panel in a first operating state B1 for a restricted viewing angle and can be operated in a second operating state B2 for an unrestricted viewing angle.
• a flat lighting source which consists of self-luminous or illuminated surfaces (F1, F2, ...) for backlighting an LCD panel, whereby the LCD panel in a first operating state B1 for a restricted viewing angle and can be operated in a second operating state B2 for an unrestricted viewing angle.
• each switchable absorber has the geometry of a perforated diaphragm.
• the perforated diaphragms can be arranged on the partial surface (s) of the common substrate or the respective substrate in such a way that the geometric centers of gravity of the self-illuminating or illuminated surfaces F1, F2, ... and that of the switchable absorbers are not Covered area parts in parallel projection do not fall on top of each other at least for some of the areas F1, F2, ... It can thus be achieved that the restricted directions of light propagation of the individual surfaces F1, F2, , F2, ... on the left edge, emit or emit light to the right, i.e. towards the observer, and on the right edge, light to the left, i.e. again towards the observer. In this way, improved homogeneity can be achieved despite restricted light directions.
• each switchable absorber has the geometry of an inverse perforated diaphragm.
• an inverse perforated diaphragm as noted earlier, those partial areas or areas of a substrate that are otherwise not covered, and vice versa, are covered with a switchable absorber compared to a non-inverse perforated diaphragm.
• the operating state B1 is generated for a restricted mode.
• the light emitted by the surface F1 is now absorbed by the switchable absorber.
• rays that are totally reflected internally in the substrate still get spatially next to the absorber within the substrate.
• microstructured outcoupling elements are arranged on partial surfaces not covered by the absorbers, which decouple the aforementioned internally totally reflected rays under a change of direction from the common substrate or the respective substrate, with the light decoupled by the microstructured outcoupling elements only from the restricted viewing angle is visible.
• the invention can be developed in that permanently scattering microstructures are arranged on the switchable absorbers.
• the use of permanently scattering microstructures on the switchable absorbers is an effective means for all embodiments of the invention in order to optimize the light distribution, in particular for the operating state B2.
• the scattering microstructures do not come into play because the absorbers are switched to be absorbent there and thus virtually no or almost no light from an area F1 reaches the scattering microstructures.
• a mutually complementary part of the switchable absorbers is switched to be complementary absorbing and transmitting.
• half of the absorbers can be switched to be absorbent and the other half to be switched to be transmitting.
• the circuits are then inverted, ie the first-mentioned half is switched to be transmitting and the second-mentioned half of the absorber is switched to be absorbing.
• there should be at least two per pixel switchable absorbers may be present, one of the first and second halves being heard.
• both operating states B5 and B6 that can be switched on are cyclically clocked for a temporally sequential light direction influencing.
• This can be used, for example, to generate images in two different directions, for example in order to image two different, time-sequentially displayed images due to the method according to the invention, one after the other and cyclically in different directions. If this is presented quickly enough, i.e. above the flicker fusion frequency of the human eye, depending on the direction and image content on the areas F1, F2, ... either autostereoscopic representations (both eyes of a viewer see two different images quasi-simultaneously) or at the same time two different images for two different viewers (so-called dual view) are made possible.
• a method for influencing the directions of light propagation of several adjacent self-luminous and / or illuminated surfaces F1, F2, ... is used, in which the surfaces F1, F2, ... comprise a transparent substrate on the light exit side, said substrate being arranged above the light-generating layer of the self-luminous or illuminated surfaces F1, F2, ..., and where in a first alternative each surface F1, F2, ...
• this switchable absorber comprises its own substrate and in a second alternative all surfaces F1, F2, respective substrate or in the second alternative on one or more partial areas of the common substrate, the spatial Liche main direction of propagation of this switchable absorber is parallel to the light exit surface of the substrate or the sub strate up to a tolerance of a maximum of 10 °, and in front of each surface F1, F2, .. at least two separately switchable absorbers are present, each complementary to each other transparent and can be switched to opaque,
• the refractive index ratios in the structure and the thickness of the substrate with the operating states B5 and B6 are switched on one after the other et and on the areas F1, F2, ... alternately at least two different image contents are displayed in the same cyclical cycle, so that depending on the first and second restricted viewing angle and depending on the displayed image contents on the areas F1, F2, ... an autostereoskopi cal or a dual view display is achieved.
• the object of the invention is also achieved by an arrangement according to the invention for influencing the directions of light propagation, comprising several adjacent self-luminous and / or illuminated surfaces (F1, F2, ...), which comprise a transparent substrate on the light exit side, wherein said substrate is arranged above the light-generating layer of the self-luminous or illuminated surfaces (F1, F2, ...) , and wherein in a first alternative each surface (F1, F2, ...) comprises its own substrate and in a second alternative all surfaces (F1, F2, ...) comprise a common, two-dimensionally extended substrate, for at least a number of surfaces (F1, F2, ...) on the light exit side in the first alternative on one or more partial surfaces of the respective substrate or in the second alternative on one or more partial surfaces of the common substrate, switchable absorbers, the main spatial propagation direction of this switchable absorber is parallel to the light exit surface of the substrate or the sub strate up to a tolerance of a maximum of 10 °,
• the geometric shape of the switchable absorber, the geometric shape of the respective surface (F1, F2, ...), the refractive index ratios in the structure and the thickness of the substrate are defined, and so that the absorbing effect of the switchable absorber for a second Operating state B2 is switched off, which means that the light emanating from the surfaces (F1, F2, ...) except for residual absorption
• the switchable absorber's absorption losses can propagate through them unhindered, so that the light of the respective affected areas (F1, F2, ...) is visible
• FIG. 3 shows a schematic diagram to explain the restriction of obliquely directed beams in a first embodiment
• FIG. 5 shows a schematic diagram to explain the method according to the invention in an expanded embodiment in the operating state B1
• FIG. 6 shows a schematic diagram to explain the method according to the invention in an expanded embodiment in the operating state B2
• each switchable absorber has the geometry of a perforated diaphragm and the geometric centers of gravity shift from area to area
• 9a and 9b are schematic sketches of an embodiment in which an inverse pinhole is used and in which internally totally reflected rays are used,
• Fig.10a and Fig.10b are schematic sketches of an embodiment in which permanently scattering microstructures are used on the switchable absorbers, as well as 11a and 11b are basic sketches for an embodiment with operating states B5 and B6, in which different images can be displayed in different directions.
• the drawings are not true to scale and only represent basic representations.
• FIG. 1 shows a schematic diagram to explain the method according to the invention in the operating state B1.
• FIG. 2 shows the operating state B2.
• each surface has its own substrate 1 or, in a second alternative, all surfaces (F1, F2, ...) use a common substrate 1.
• Said substrate 1 is arranged above, but not necessarily directly above, the layer of self-luminous or illuminated surfaces (F1, F2,%) Generating light, as shown in FIG.
• the method according to the invention now comprises the following steps: for at least a number of surfaces (F1, F2,%) Arranging switchable surfaces
• a restricted viewing angle does not necessarily mean that no light at all is emitted in certain directions. Rather, a certain amount of residual light can still be emitted there, which, however, prevents comfortable vision. Typical values for such residual light (measured as luminance) even in zones intended for restricted visibility are a few percent of the peak value (which can be perceived from the dedicated viewing zone of the restricted viewing angle).
• each area (F1, F2, ...) comprises its own substrate 1 (or 1.1, 1 .2, 1 .3 etc.). These substrates are then preferably arranged essentially in one plane.
• all surfaces (F1, F2,...) Comprise a common, two-dimensionally extended substrate 1.
• Said restriction of the light propagation of the light emanating from each individual surface is carried out, for example, by arranging permanently absorbing layers 3 between - in the first alternative - the individual substrates 1, or - in the second alternative - within the one common substrate 1.
• This approach is shown in Figure 3, where a schematic diagram of the restriction of obliquely directed rays is shown in a first embodiment.
• the absorbent layers 3 can For example, there are opaque particles in an adhesive, silicone or a polymer. Alternatively, they can also consist of an opaque solid material such as metal or one or more vapor-deposited layers. According to the relationships according to FIG.
• the absorbent layer 3 can also be switched between a transparent and an absorbent state.
• the planes in which the switchable absorber 2 and the (permanently or optionally switchable) layers 3 are each arranged are preferably perpendicular to one another with a tolerance of a maximum of 25 degrees.
• FIG. 4 shows a schematic diagram of the restriction of obliquely directed beams in a second embodiment.
• the light propagation of the light emanating from each individual surface is limited by choosing the refractive index ratios of the substrate 1 compared to air in such a way that undesired rays in the direction of neighboring partial surfaces are converted into total reflection (in 4 indicated with the dashed line) and thus be extinguished for the light balance.
• a permanent absorber (not shown in the drawing) is then usually attached to the narrow sides of the substrate in order to absorb this light from the angles of total reflection.
• a collimating lens 4 is arranged on each of the partial surfaces of the substrates 1 or of the substra tes 1, on which no switchable absorber 2 is applied, in order to achieve further beam focusing and to restrict the viewing angle even better enable.
• FIG. 5 shows a schematic diagram to explain this variant in operating state B1
• FIG. 6 shows a schematic diagram in operating state B2.
• Each switchable absorber 2 can comprise, for example, an electrochromic layer and / or a liquid crystal layer and / or a layer based on electrophoresis and / or a layer based on electrowetting with absorbing particles, each of which can be controlled by an electric field. In this way, the absorbing effect can be easily switched on and off. Means for controlling this are of course available.
• electrochromic layers as absorbers 2 these can be, for example, inexpensively vapor-deposited onto the substrate or substrates 1 and contacted with electrodes for control.
• each switchable absorber 2 comprises a switchable color filter, which in each case absorbs the color spectrum of the color emitted by an area (F1, F2,%) Underneath in a first state and in a second condition was transmitted, whereby the switchable color filter can be controlled with regard to its state by an electric field.
• These can be quantum dots, for example.
• Each switchable absorber 2 preferably has the geometry of a perforated diaphragm. It is explicitly possible here for more than one (permanently) non-absorbing geometric component to be provided per switchable absorber 2 or per perforated diaphragm. 7a-7h show various basic sketches in plan view of possible design variants of the switchable absorber 2. If an absorber according to one of the drawings FIGS. 7a-7h is arranged in front of each surface (F1, F2, ). The following influences on the directions of light propagation in each case in the operating state B1 compared to the operating state B2 (assuming that an observer would look at the substrates 1 approximately around their mid-perpendicular):
• 7g Restriction of the directions of light propagation in all directions above the substrate 1, but with a cone-like angle of propagation which has two circular cross-sections
• 7h Limitation of the directions of light propagation to the left and right as well as up and down in such a way that only light reaches outside a cone-like blocking angle that has a circular cross-section (so-called inverse pinhole shape).
• FIGS. 7a-7h an identification with the substrate 1 is drawn in at the points at which no absorber components 2 are applied. This is intended to illustrate in particular that the absorber 2 does not cover the entire area of the sub strate ⁇ ) 1.
• switchable absorbers 2 it is also possible for different switchable absorbers 2 to have different geometric shapes, for example according to two or more of the drawings in FIGS. 7a to 7h. Often, however, all absorbers 2 will have essentially the same geometric shape. When applying the same shape to all absorbers 2, these can still be stretched or compressed slightly towards the edge with a correction factor.
• an absorber 2 can have the geometry of an inverse perforated diaphragm, as shown in FIG. 7h (inverse to FIG. 7d).
• an inverse perforated diaphragm in contrast to a non-inverse perforated diaphragm, those partial areas or areas of a substrate that are otherwise not covered are covered with a switchable absorber, and vice versa.
• Such a multi-hole diaphragm is used in special embodiments of the invention (see description of FIG. 9a and FIG. 9b).
• the surfaces of the absorbers 2 can be a few dozen square micrometers to a few square millimeters, possibly even more. Further configurations are conceivable and can be implemented depending on the application.
• the variant according to FIG. 7g can, for example, also be designed in such a way that the left absorber part of each absorber 2 (i.e. the part to the left of the dashed line) is switched to be absorbent for an operating state B5 and the other, right half to be switched to transmit.
• the circuits are then inverted, ie the first-mentioned half is transmitting and the second-mentioned half of the absorber 2 is switched absorbing. It is thus possible, for example, for the light from the surfaces to be released alternately in one direction and then in another direction when operating states B5 and B6 are cyclically clocked.
• the operating states B5 and B6 are clocked through cyclically for a temporally sequential influencing of the direction of the light.
• This can be used, for example, to generate images in two different directions the, for example, to depict two different, temporally sequentially displayed images due to the method according to the invention in each case one after the other and cyclically in different directions. If this is presented quickly enough, i.e. above the flicker fusion frequency of the human eye, depending on the direction and image content on the areas F1, F2, ... either autostereoscopic representations (both eyes of an observer see two different images quasi-simultaneously) or two different images for two different viewers (so-called dual view) can be made possible at the same time.
• 11 a and 11 b show basic sketches for an embodiment with Radio-Luminescence states B5 and B6, in each of which different images can be displayed in different directions.
• a method for influencing the light propagation directions of several adjacent self-luminous and / or illuminated surfaces F1, F2, ... is used in this embodiment, in which the surfaces F1, F2, ... comprise a transparent substrate 1 on the light exit side , wherein said substrate 1 is arranged above the light-generating layer of the self-luminous or illuminated surfaces F1, F2, ..., and wherein in a first alternative each surface F1, F2, ... comprises its own substrate 1 and in a second alternative all surfaces F1, F2, ...
• switchable absorbers 2 comprise a common, two-dimensionally extended substrate 1, comprising the following steps: for at least a number of surfaces F1, F2, ... arranging switchable absorbers 2 on the light exit side in the first alternative on one or several partial areas of the respective substrate 1 or, in the second alternative, on one or more partial areas of the common substrate 1 , the spatial main direction of propagation of these switchable absorbers 2 is parallel to the light exit surface of the substrate or substrates 1 to a tolerance of a maximum of 10 °, and where in front of each surface F1, F2, .. at least two separately switchable absorbers 2 are present, which can be switched to be transparent and opaque, complementary to each other,
• the operating states B5 and B6 are cyclically clocked one after the other switched on and alternately at least two different image contents are displayed on the areas F1, F2, ... in the same cyclical cycle, so that depending on the first and second restricted viewing angle and depending on the displayed image contents on the areas F1, F2, ... one autostereoskopi cal or a dual view display is achieved.
• 11 a shows the operating state B5: There, through the selection of switchable absorbers 2-a, which are switched opaque here, only light rays are allowed to pass through to the right (ie through the transparently switched switchable absorbers 2-b of the complementary selection through).
• the aforementioned restriction of the light propagation of the light emanating from each individual surface (F1, F2, 7) takes place, for example, by arranging permanently absorbing layers 3 between - in the first alternative - the individual substrates 1, or - in the second alternative - within the one common substrate 1.
• Fig. 11 b shows the next cycle in the cycle with the operating state B6:
• switchable absorbers 2-b which are switched opaque here, only light rays are allowed to pass through to the left (i.e. through the switchable absorbers 2- a of the complementary selection).
• the method according to the invention is of particular practical importance when even luminous areas (F1, F2, ...) are present in a large number, each of which corresponds to the smallest pixel of an OLED, miniLED, VCSEL, QLED, LED or micro LED screen corresponds so that such a screen can be switched between an operating state B1 for a restricted viewing angle and an operating state B2 for a non-restricted viewing angle.
• the smallest pixels are either RGB sub-pixels (red, green, blue), other monochrome or full-color pixels, depending on the design of the imaging technology.
• the screen technology can be generally self-illuminating or illuminated, such as LCD, SED, FED or others.
• each switchable absorber 2 has the geometry of a perforated diaphragm.
• the apertured diaphragms can be arranged on the partial surface or surfaces of the common substrate 1 or the respective substrate 1 in such a way that the geometric focal points of the self-luminous or illuminated surfaces F1, F2, ... and of the switchable absorbers 2 uncovered surface portions in parallel projection at least in the case of a part of the surfaces F1, F2, ... do not coincide with one another.
• Fig. 8 This means that the restricted directions of light propagation of the individual surfaces F1, F2, ... are varied, particularly advantageously so that when a viewer 7 looks at the surfaces F1, F2, ...
• each switchable absorber 2 has the geometry of an inverse perforated diaphragm (as shown, for example, in FIG. 7h).
• an inverse perforated diaphragm in contrast to a non-inverse perforated diaphragm, those partial areas or areas of a substrate which are otherwise not covered are covered with a switchable absorber 2, and vice versa.
• FIG. 9a in which a switchable absorber is arranged essentially frontally opposite the self-illuminating or illuminated surface F1, the operating state B1 is shown for a restricted mode.
• the light emitted by the surface F1 is now absorbed by the switchable absorber 2.
• rays that are totally reflected internally in the substrate 1 still get spatially next to the absorber 2 within the substrate 1.
• microstructured decoupling elements 5 are arranged on partial surfaces not covered by the absorbers 2, which decouple the aforementioned internally totally reflected rays with a change in direction from the common substrate 1 or the respective substrate 1, which is achieved by the microstructured decoupling elements 5 decoupled light is only visible from the restricted viewing angle. This is indicated in FIG. 9a with the light beam coupled out upwards.
• FIGS. 10a and 10b show further configurations in which permanently scattering microstructures 6 are arranged on the switchable absorbers 2. While the basic sketches Fig.10a and Fig.10b can be seen as corresponding developments of the designs according to Fig.5 and Fig.6, the use of permanently scattering microstructures 6 on the switchable absorbers is an effective means for all the designs described. in order to optimize the light distribution, especially for operating mode B2. According to FIG. 10a, the scattering microstructures 6 do not come into play in the operating state B1, because the absorbers 2 are switched there to be absorbent and thus virtually no light from an area F1 reaches the scattering microstructures 6.
• Fig.l Ob shows that in the operating state B2, in which the switchable absorbers 2 are switched transparently, the scattering microstructures 6 from internally totally reflected (and depending on the position - not shown here) possibly also directly from the area F1 the absorber 2 reaching light is scattered in order to optimize the light distribution in particular for the operating state B2 by scattering.
• FIG. 1 and FIG. This comprises several adjacent self-luminous and / or illuminated surfaces (F1, F2, ...) which (each) comprise a transparent substrate 1 on the light exit side, said substrate 1 above the light-generating layer of the self-luminous or illuminated surfaces (F1, F2 , ...) is arranged, and in a first alternative each surface (F1, F2, ..) comprises its own substrate (1) and in a second alternative all surfaces (F1, F2, ...) a common, Comprising a flat substrate (1) for at least a number of surfaces (F1, F2, ...) on the light exit side in a first alternative on one or more partial surfaces of the respective substrate 1 or in the second alternative on one or more partial surfaces of the common substrate (1) arranged switchable absorber 2, the spatial main direction of propagation of this switchable absorber 2 up to a tolerance of a maximum of 10 ° parallel to the light exit surface of the substrate or substrates 1 is located,
• Both the method and the arrangement according to the invention for influencing the directions of light propagation solve the problem: Both the method and the arrangement are inexpensive and suitable for mass production can be implemented and, in particular, can be used universally with OLED screens, but also with other types of screen types to enable switching between a privacy screen and a free viewing mode, the resolution of such a screen being essentially not reduced.
• the invention described above can advantageously be used in conjunction with an image display device wherever confidential data is displayed and / or entered, such as when entering a PIN or for displaying data on ATMs or payment terminals or for entering passwords or when reading from Emails on mobile devices.
• the invention can also be used in a car in order to present the driver with selectable content in a visible manner or, alternatively, not to hit him with disruptive image content. Further applications are in the field of lighting and advertising, in particular to avoid light smog.

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• Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
• Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)

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• 2020
  • 2020-03-26 DE DE102020002052.6A patent/DE102020002052A1/de active Pending
• 2021
  • 2021-03-16 US US17/758,614 patent/US12147123B2/en active Active
  • 2021-03-16 JP JP2022543542A patent/JP7432965B2/ja active Active
  • 2021-03-16 CN CN202180010594.2A patent/CN114981718B/zh active Active
  • 2021-03-16 WO PCT/EP2021/056653 patent/WO2021190997A1/de not_active Ceased

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