DE102021000968B3 - Dual mode screen B1 for a clear view mode and B2 for a restricted angle or dual view mode - Google Patents

Abstract

The invention relates to a screen (1), which can be operated in at least two operating modes B1 for a free view mode and B2 for a restricted angle range or a dual view mode, comprising a transmissive image generator (2), preferably an LCD panel, including an electronic one Control for the defined display of image content on the image generator (2), a backlight (4), a two-dimensional component (3) arranged in front of the backlight (4) in the viewing direction and having sections (3a) which light incident on it in each case with a transmit a transmittance selectable between a minimum value and a maximum value in order to achieve a dynamic increase in contrast, and means for switching between the operating modes B1 and B2.

Description

field of invention

In recent years, great advances have been made in widening the viewing angle of LCDs. However, there are often situations in which this very large viewing area of a screen can be a disadvantage. Information is also increasingly available on mobile devices such as notebooks and tablet PCs, such as bank details or other personal details and sensitive data. Accordingly, people need control over who can see this sensitive data; they need to be able to choose between a wide viewing angle in order to share information on their display with others, e.g. when looking at holiday photos or for advertising purposes. On the other hand, they need a small viewing angle if they want to keep the image information confidential.

A similar problem arises in vehicle construction: the driver must not be distracted by image content such as digital entertainment programs when the engine is switched on, while the passenger would like to consume the same while driving. A screen is therefore required which can switch between the corresponding display modes.

State of the art

Additional films based on micro-lamellas have already been used for mobile displays in order to achieve visual data protection. However, these foils were not switchable, they always had to be applied by hand and then removed again. You also have to transport them separately to the display when you don't need them. A significant disadvantage of the use of such lamellar foils is also associated with the associated loss of light.

the U.S. 6,765,550 B2 describes such a privacy screen using micro-slats. The biggest disadvantage here is the mechanical removal or mechanical attachment of the filter and the loss of light in protected mode.

In the US 5,993,940A describes the use of a film that has small prism strips evenly arranged on its surface in order to achieve a privacy mode. Development and production are quite complex.

In the WO 2012/033583 A1 switching between free and restricted vision is generated by driving liquid crystals between so-called "chromonic" layers. This results in a loss of light and the effort is quite high.

the US 2012/0235891 A1 describes a very complex backlight in a screen. There come according to 1 and 15 not only several light guides are used, but also other complex optical elements such as microlens elements 40 and prism structures 50, which transform the light from the rear lighting on the way to the front lighting. This is expensive and complex to implement and also associated with light loss. According to the variant after 17 in the US2012/0235891 Both the light sources 4R and 18 produce light with a narrow illumination angle, and the light from the rear light source 18 is first converted into light with a large illumination angle with great effort. This complex conversion is - as already mentioned above - strongly reducing the brightness.

According to the JP 2007-155783 A special optical surfaces 19 that are complex to calculate and produce are used, which then deflect light into different narrow or wide areas depending on the angle of incidence of the light. These structures resemble Fresnel lenses. There are also interference edges that deflect light in undesirable directions. It therefore remains unclear whether sensible light distributions can actually be achieved.

In the U.S. 2013/0308185 A1 describes a special light guide designed with steps, which emits light over a large area in different directions, depending on the direction from which it is illuminated from a narrow side. In interaction with a transmissive image display device, for example an LC display, a screen that can be switched between free and restricted viewing modes can thus be produced. One of the disadvantages here is that the limited visual effect can be generated either only for left/right or for up/down, but not for left/right/up/down simultaneously, as is necessary for certain payment transactions. In addition, a residual light is still visible even in restricted viewing mode from blocked viewing angles.

the WO 2015/121398 A1 The applicant describes a screen with two operating modes, in which scattering particles are present in the volume of the corresponding light guide, which is essential for switching the operating modes. However, the scattering particles selected there from a polymer usually have the disadvantage that light is decoupled from both large areas, which means that about half of the useful light is emitted in the wrong direction, namely towards the backlight, and not in the right direction due to the structure appropriate extent can be recycled. In addition, the scattering particles made of polymer distributed in the volume of the light guide can, under certain circumstances, particularly at higher concentrations, lead to scattering effects which reduce the visual protection effect in the protected operating mode.

In the DE 10 2019 006 022 B3 the applicant describes an optical element with variable transmission. Particles that can be moved electrophoretically or magnetophoretically are used here. However, this document does not mention any means for explicitly increasing the image contrast.

the US 6,211,930 B1 reveals vari-angle LCD screens. A switchable diffuser is used, which can switch between a scattering and a transparent mode. Here, too, it is not described how an increased image contrast can be achieved.

In the JP 2007-155 784 A describes an LCD screen that can switch between a wide and a narrow viewing angle. Switching is achieved using electrochromic fins. Again, how increased image contrast is made possible is not described.

Finally revealed the DE 10 2015 012 271 B4 Applicant discloses a method and screen that can be used in at least two modes of operation for a clear view mode and a restricted view mode. The change in the refractive index of liquid crystals is used for this. Within the scope of this document, no means for explicitly increasing the image contrast are mentioned.

The aforementioned methods and arrangements usually have the disadvantage in common that they significantly reduce the brightness of the basic screen and/or require a complex and expensive optical element for mode switching and/or do not allow a dual-view mode and/or Contrast reproduction are limited.

Description of the invention

It is therefore the object of the invention to describe a screen which enables the defined viewing of image content from predeterminable angular ranges, with the aim of achieving the highest possible image contrast at the same time.

• - einen transmissiven Bildgeber, vorzugsweise ein LCD-Panel, einschließlich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten auf dem Bildgeber,
• - eine Hintergrundbeleuchtung,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung angeordnete flächig ausgedehnte Komponente mit Abschnitten, welche auf sie einfallendes Licht in jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittieren,
• - Mittel zur Umschaltung zwischen den Betriebsarten B1 und B2.

According to the invention, this object is achieved by a screen that can be operated in at least two operating modes B1 for a free view mode and B2 for a view mode that is restricted in the angular range or a dual view mode

• - a transmissive imager, preferably an LCD panel, including an electronic control for defined display of image content on the imager,
• - a backlight,
• - an extensive component arranged in the viewing direction in front of the background lighting and having sections which transmit light incident on them with a transmittance that can be selected between a minimum value and a maximum value,
• - Means for switching between the operating modes B1 and B2.

The two-dimensionally extended component arranged in front of the background lighting in the viewing direction can be used both in front of and behind the imaging device. For the considerations mentioned below, it should be regarded as lying behind the imager without loss of generality. The areas of the sections of the two-dimensionally extended component, which each transmit light incident on them with a transmittance that can be selected between a minimum value and a maximum value, can correspond in their area approximately to the area of a pixel or a subpixel of the imaging device. However, the size of the area of sections is preferably the corresponding size of entire clusters of pixels, so that a section covers a defined number of pixels of the imager in the case of parallel projection along the perpendicular bisector of the imager. For example, these can be rectangular sections that cover approximately 5×5, 10×5, 5×10, 20×20, 30×30, 10×20, 20×10, 50×50, 100×50 or 50×100 pixels in said parallel projection. Other area sizes and/or shapes of the sections are possible.

Particularly preferably, the transmittance of the respective sections of the two-dimensionally extended component is controlled as a function of the image content displayed on the imager, in particular by said electronic control of the imager. Due to the locally adjustable transmittance, the purpose of the areally extended component with the sections is, in particular, to improve the perceptible image contrast by using a local dimming approach. For example, in the case of dark parts of an image content, the corresponding sections can be controlled with a low degree of transmission, while in the case of light parts of an image content, the corresponding sections can be controlled with a high degree of transmission be controlled. Further details on local dimming approaches are known in the prior art and do not require any further explanation here.

The two-dimensionally extended component can, for example, comprise a liquid crystal panel with polarizers in order to achieve the defined local dimming, ie the setting of transmittance. One of the polarizers of the two-dimensionally extended component can, for example in the case of an LCD panel as the imaging device, also form a polarizer of the LCD panel.
Thus, the two-dimensionally extended component can preferably be designed as a module with the imager.
Other configurations of the two-dimensionally extended component are of course possible, for example using electrochromism, electro-wetting, electrophoresis, magnetophoresis or other technical-optical active principles.
Depending on the configuration, the degrees of transmission that can be achieved in the sections (when measured with white-mixed light perpendicular to the surface) are generally between <0.001% and 50% or more.

In a first embodiment of the screen, the means for switching between the operating modes B1 and B2 are implemented by arranging a prism grid and/or a lenticular grid and/or a barrier screen with a transparent-opaque pattern with a period P in front of or behind the image generator , so that when a single image content B is displayed on the imager in the B1 operating mode, this can be perceived from a wide angular range W1 (i.e. greater than 60 degrees laterally), and so that when two interlaced image contents L, R are displayed on the Imager in operating mode B2 for a dual viewing mode, in which the period PB of the interlaced image contents L, R when displayed on the imager corresponds to the said period P up to a maximum tolerance of three percent, the image contents L, R each predominantly from different Angle ranges W2, W3 can be perceived.
In this context, the term "predominantly" means that a complete channel separation of the angle ranges W2 and W3 is technically practically impossible to achieve and therefore there is a certain overlap, albeit small, also known as "crosstalk", of the angle ranges W2 and W3. Typically, the luminance in such overlapping areas is a maximum of 3% of the maximum peak luminance shown in each of the angular areas. For example, an image content shown in angle range W2 with 100% peak luminance could be visible at a maximum of 3% of the peak luminance in angle range W3. However, the degree of overlap is preferably less than 3%, in particular at most 1% or at most 0.5%.
The optical design of the prism grid, the lenticular grid or the barrier screen with a transparent-opaque pattern, each with a period P, is familiar to the person skilled in the art and is done in particular taking into account the desired angular ranges W2 and W3, the dimensions (and positions) of the pixels of the imager, in particular the period PB in the interlacing of the image contents L, R, the period P, the refractive indices involved (e.g. for prism or lens grids, cover glass of the LCD panel) and the general geometrical positional conditions.
It is advantageous here if, in operating mode B2 for a dual viewing mode, the respective period limits of the prism grid, lenticular grid or barrier screen correspond to the period limits of the respective two interlaced image contents L, R on the image generator in the case of parallel projection, each with a tolerance of a maximum of 300 μm, preferably a maximum of 100 μm.

The advantage of this first embodiment over the prior art is in particular that due to the areally extended component in contrast, an enhanced image perception can be presented both in a dual viewing mode (also called dual-view mode) and in a public viewing mode. The implementation, for example, with a prism grid and a liquid crystal panel with polarizers, i.e. extensive components, can be implemented inexpensively.

In a second embodiment of the screen, the means for switching between the operating modes B1 and B2 are implemented in that the backlight can switch between at least two operating modes B1 and B2, with the backlighting in operating mode B1 light being measured horizontally in a direction from a viewer - Radiates an angular range W1 of more than 60 degrees, so that when a single image content B is displayed on the imager in B1 mode, this can be perceived from a wide angular range W1 (which is laterally greater than 60 degrees), and the background lighting in the Operating mode B2 emits light in a narrow angular range W2 of less than 60 degrees, measured horizontally from the direction of an observer, with residual light of a maximum of five percent (preferably a maximum of 1 or 2 percent) of the peak luminance being disregarded outside of this said angular range W2, so that when displaying a single image content B on the image generator in the operating mode B2, this can only be perceived from a limited angular range W2. For technical reasons, it may be that, as described above, a few percent light (measured at the peak luminance in the angular range W2) outside of the angular range W2 be radiated. This residual light should be as small as possible in order to offer a viewer outside the angular range W2 an image that is as imperceptible as possible or at least barely perceptible.
Exemplary configurations of a corresponding backlight are described, inter alia, in the documents EP 3 570 097 A1 , U.S. 10,712,488 B2 , US 10,838,133 B2 such as EP 3552056 B1 the applicant.
In addition, the background lighting in the B1 or B2 operating mode can also have a disruptive light distribution (ie with two or more peaks), as long as the desired visibility conditions can be achieved with the aforementioned angular ranges W1 or W2.
The advantages of this second embodiment over the prior art are the use of local dimming approaches to increase contrast in screens that can be switched in the angle range of the radiation, with the integration of the extensive component with the image generator as a module in particular embodying a cost-effective and effective design.

In the third embodiment of the screen, the means for switching between operating modes B1 and B2 are implemented in that, in operating mode B1, in which all sections 3a of the two-dimensionally extended component have a selectable transmittance (in particular depending on the image content displayed on the imager , as already described above) and when a single image content B is displayed on the imager, this can be perceived from a wide angular range W1 (ie, more than 60 degrees laterally), and that when two image contents L, R that are periodically interlaced are displayed on the Imager in operating mode B2 for a dual viewing mode, in which the areally extended component represents an opaque pattern of a barrier screen with the period PD on a real selection of sections and implements a selectable transmittance on the complementary selection of sections, and in which the Peri ode PB of the interlaced image contents L, R when displayed on the image generator up to a maximum tolerance of three percent with said period PD, said image contents L, R can be perceived predominantly from different angular ranges W2, W3.
By "true" selection of sections it is meant that not all sections are selected at the same time, and no section is selected at the same time.
Said opaque pattern of a barrier screen means that the selection of sections is switched to the minimum transmittance, while the complementary sections of the two-dimensionally extended component have a selectable transmittance, which is preferably defined using the local dimming mechanisms mentioned further above.
The comments made above on the term “predominantly” also apply here. The advantages of this third embodiment compared to the prior art are in particular the enabling of a high-contrast display, which can be displayed either in a wide angular range or in a dual-view mode in two (apart from the "crosstalk") disjoint angular ranges. In principle, even more than two angle ranges are possible, for example for a “triple view” design. Furthermore, the contrast is particularly high in the dual-view mode, because the selection of opaque sections ensures reduced dark values in the luminance in any case and regardless of the image content, while the maximum values of the luminance are basically achieved by the sections whose transmittance can be adjusted.
A particularly outstanding means-effect relationship here is that the contrast-enhancing layer, ie the two-dimensional component, is also responsible for the light direction-selective effect in dual-view mode, ie for the optical generation of the angular ranges.

• - wobei in jedem Takt T1, T2 zwei ineinander periodisch verschachtelte Bildinhalte L, R auf dem Bildgeber wiedergegeben werden und die Verschachtelung der Bildinhalte L, R zwischen den Takten T1, T2 alterniert,
• - wobei ferner die flächig ausgedehnte Komponente auf einer echten Auswahl an Abschnitten (d.h. mit minimalem Transmissionsgrad) ein opakes Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären Auswahl an Abschnitten einen jeweils wählbaren Transmissionsgrad umsetzt und dabei zwischen den Takten T1, T2 die genannten Auswahlen an Abschnitten alternieren,
• - und bei dem die Periode PB der verschachtelten Bildinhalte L, R bei Darstellung auf dem Bildgeber jeweils bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt,
• - so dass die besagten Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 und im zeitlichen Mittel in der vollen Auflösung des Bildgebers wahrgenommen werden können.

In the fourth embodiment of the screen, which is based on the third embodiment, in the operating mode B2 for a dual viewing mode, at least two clocks T1, T2 are converted periodically one after the other,

• - whereby in each cycle T1, T2 two periodically interlaced image contents L, R are reproduced on the image generator and the interlacing of the picture contents L, R alternates between cycles T1, T2,
• - Wherein the areally extended component represents an opaque pattern of a barrier screen with the period PD on a real selection of sections (i.e. with minimum transmittance) and on the complementary selection of sections converts a respective selectable transmittance and thereby between the clocks T1, T2 the mentioned selections of sections alternate,
• - and in which the period PB of the interlaced image contents L, R when displayed on the image generator corresponds to the said period PD up to a maximum tolerance of three percent,
• - So that said image content L, R can be perceived predominantly from different angular ranges W2, W3 and on average over time in the full resolution of the imager.

The above definition of the word “predominantly” also applies here. The benefits of this fourth embodiment compared to the third embodiment are, in particular, the full-resolution representation of the image contents in different angular ranges with a simultaneous increase in contrast over time.

• - wobei in der Betriebsart B1, in welcher alle Abschnitte der flächig ausgedehnten Komponente einen jeweils wählbaren Transmissionsgrad aufweisen, bei Darstellung eines einzigen Bildinhaltes B auf dem Bildgeber dieser aus einem breiten Winkelbereich W1 (d.h. mehr als 60 Grad lateral) wahrnehmbar ist,
• - und wobei in der Betriebsart B2 für einen im Winkelbereich eingeschränkten Sichtmodus, in welcher die flächig ausgedehnte Komponente auf einer echten Auswahl an Abschnitten ein opakes (d.h. mit minimalem Transmissionsgrad) Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären Auswahl an Abschnitten einen jeweils wählbaren Transmissionsgrad umsetzt, wobei ferner die Periode PF bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt, so dass bei Darstellung eines einzigen Bildinhaltes B auf dem Bildgeber dieser lediglich aus einem eingeschränkten Winkelbereich W2 wahrnehmbar ist.

In the fifth embodiment of a screen, the means for switching between the operating modes B1 and B2 are implemented in that a static barrier screen with a transparent-opaque pattern with a period PF is also arranged in front of the background lighting in the viewing direction,

• - wherein in operating mode B1, in which all sections of the two-dimensionally extended component have a selectable transmittance, when a single image content B is displayed on the imager, this can be perceived from a wide angular range W1 (ie more than 60 degrees laterally),
• - and in the operating mode B2 for a viewing mode limited in the angular range, in which the areally extended component represents an opaque (i.e. with minimal transmittance) pattern of a barrier screen with the period PD on a genuine selection of sections and on the complementary selection of sections converts a selectable degree of transmittance, with the period PF also matching said period PD up to a maximum tolerance of three percent, so that when a single image content B is displayed on the image generator, it can only be perceived from a limited angular range W2.

The above definition of “predominantly” also applies here. The static barrier screen can be arranged in front of the background lighting in the viewing direction, but behind the two-dimensionally extended component, or behind the imager or else in front of the imager. The advantages of this fifth embodiment compared to the prior art are, in particular, the even higher contrast that is made possible due to the static barrier, which is already significantly and dynamically increased by the two-dimensionally extended component compared to the achievable contrast of the individually used imager, with switching between a wide and a narrow angular range is made possible.

• - einen transmissiven Bildgeber, vorzugsweise ein LCD-Panel, einschließ-lich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten L, R auf dem Bildgeber,
• - eine Hintergrundbeleuchtung,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung angeordnete flächig ausgedehnte Komponente, deren Abschnitte auf sie einfallendes Licht in jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittieren,
• - ein Prismenraster und/oder ein Linsenraster und/oder einen Barriereschirm mit einem transparent-opaken Muster mit einer Periode P, welches bzw. welcher vor oder hinter dem Bildgeber angeordnet ist, so dass bei Darstellung zweier ineinander periodisch verschachtelter Bildinhalte L, R auf dem Bildgeber in der Betriebsart B2 für einen dualen Sichtmodus, bei dem die Periode PB der verschachtelten Bildinhalte L, R bei Darstellung auf dem Bildgeber bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode P übereinstimmt, die Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 wahrgenommen werden können.

A sixth embodiment of the screen operable in at least one dual view mode includes

• - a transmissive image generator, preferably an LCD panel, including an electronic control for the defined display of image content L, R on the image generator,
• - a backlight,
• - an extensive component arranged in the viewing direction in front of the background lighting, the sections of which transmit light incident on it in each case with a transmittance that can be selected between a minimum value and a maximum value,
• - a prism grid and/or a lenticular grid and/or a barrier screen with a transparent-opaque pattern with a period P, which is arranged in front of or behind the image generator, so that when two interlaced image contents L, R are displayed on the Imager in operating mode B2 for a dual viewing mode, in which the period PB of the interlaced image contents L, R when displayed on the imager corresponds to the said period P up to a maximum tolerance of three percent, the image contents L, R each predominantly from different Angle ranges W2, W3 can be perceived.

The above description of the word "predominantly" also applies here. The two-dimensionally extended component can in turn be arranged in front of the background lighting and at the same time in front of or behind the imaging device in the viewing direction.

In principle, it should be noted here that the image contents L and R can differ, but can also be the same. In the case of equality, different viewers who are in the different angular ranges see the same image content.
The explanations given above for the first embodiment regarding the size of the sections also apply here by analogy.
The advantage of this sixth embodiment compared to the prior art lies in particular in the fact that an image perception that is enhanced in contrast due to the areally extended component can also be presented in a dual-view mode. The implementation, for example, with a prism grid and a liquid crystal panel with polarizers, i.e. extensive components, can be implemented inexpensively.

• - einen transmissiven Bildgeber, vorzugsweise ein LCD-Panel, einschließlich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten L, R auf dem Bildgeber,
• - eine Hintergrundbeleuchtung,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung angeordnete flächig ausgedehnte Komponente, welche auf sie einfallendes Licht in Abschnitten jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittiert,
• - ein in Betrachtungsrichtung vor der Hintergrundbeleuchtung angeordneter statischer Barriereschirm mit einem transparent-opaken Muster mit einer Periode PF,
• - wobei zyklisch, d.h. zeitlich periodisch, die flächig ausgedehnte Komponente auf einer ersten und einer zweiten echten Auswahl an Abschnitten abwechselnd ein opakes (d.h. mit minimalem Transmissionsgrad) Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären ersten und zweiten Auswahl an Abschnitten einen jeweils wählbaren Transmissionsgrad umsetzt, wobei ferner die Periode PF bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt, wobei die Bildinhalte L, R auch zyklisch, d.h. in derselben zeitlichen Periode, wie die Auswahlen an Abschnitten ihre Positionen wechseln, dargestellt werden, so dass im zeitlichen Mittel die Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 wahrgenommen werden.

Finally, a seventh embodiment of the screen, which can be operated in at least one dual view mode, includes

• - a transmissive imager, preferably an LCD panel, including an electronic control for the defined display of image content L, R on the imager,
• - a backlight,
• - an extensive component arranged in the viewing direction in front of the backlight, which transmits light incident on it in sections, each with a transmittance that can be selected between a minimum value and a maximum value,
• - a static barrier screen with a transparent-opaque pattern with a period PF placed in front of the backlight in the viewing direction,
• - wherein cyclically, ie periodically periodic in time, the areally extended component alternately represents an opaque (ie with minimum transmittance) pattern of a barrier screen with the period PD on a first and a second real selection of sections and on the complementary first and second selection of sections implements a transmittance that can be selected in each case, with the period PF also matching said period PD up to a maximum tolerance of three percent, with the image contents L, R also cyclically, i.e. in the same time period as the selections of sections change their positions, are displayed, so that, on average over time, the image contents L, R are each perceived predominantly from different angular ranges W2, W3.

The above explanation of "predominantly" also applies here.
The two-dimensionally extended component arranged in front of the background lighting in the viewing direction can be located in front of or behind the imaging device.
Furthermore, the explanations given for the first embodiment regarding the size of the sections of the component apply here as well. The sections can each transmit light with a transmittance that can be selected between a minimum value and a maximum value in order to improve the contrast locally using a local dimming approach. The static barrier screen can be arranged in front of the background lighting in the viewing direction, but behind the two-dimensionally extended component, or behind the imager or also in front of the imager.
If no opaque sections are provided in this embodiment in a further mode, but only sections that can be freely selected in transmission, then imaging in a wide angle range is also possible, comparable to the operating mode B1 of the fifth embodiment.
The advantages of this seventh embodiment compared to the prior art are, in particular, that with simple and inexpensive means, namely a static barrier and an extensive component, an excellent image contrast is achieved, which clearly exceeds the image contrast of the image generator, while at the same time due to the timing of the sections a dual-view mode is achieved on the extensive component.

Of course, all image content B, L, R in all configurations can be still images and/or moving images, text or other visual content.

In the first, third, fourth, sixth and seventh configuration of the screen, in which in operating mode B2 for a dual viewing mode image content L, R can be perceived predominantly from different angular ranges W2, W3, one of the angular ranges W2 or W3 preferably includes such a half-plane, which runs through the center of the image area of the imager, is at the same time perpendicular to the image area of the imager and at the same time is aligned parallel to the left edge of the image area of the imager, at least partially.

The invention also includes the use of a screen according to one of the seven design variants described above in a vehicle, with the vehicle driver in operating mode B2 not perceiving any or only image content with a maximum of two percent (residual light) of the peak brightness in the viewing mode limited in the angular range, or in the case of a dual viewing mode, perceives a different image content L than a person traveling with you who sees the image content R.
A motor vehicle, a ship, an airplane or a spacecraft can generally be considered here as a vehicle.
In the case of the dual-view display, there is also the option of superimposing the image content R actually displayed for the person traveling with you, which could also be visible to the vehicle driver as residual light, with a lighter image content L for the vehicle driver. The lighter image content L means, for example, a light static image (eg a gray or colored area). Because of this cross-fading, it can be ensured that the driver of the vehicle actually does not perceive any of the image content R that is not intended for him. A visual disturbance to the driver by image content R intended for the person traveling with him is thus avoided in any case.

In addition, depending on the dimensioning of the different angular ranges, it is fundamentally possible in all of the aforementioned configurations with a dual view mode (dual view) to achieve a glasses-free three-dimensional display when displaying stereoscopic content as image content L, R. For this purpose, the angular ranges must adjoin one another in such a way that the eyes are one or possibly several Viewers each see a different image content L, R.

In principle, the performance of the invention is retained if the parameters described above are varied within certain limits. It goes without saying that the features mentioned above and those still to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 a die Prinzipskizze eines Bildschirms in einer ersten Ausgestaltung im Betriebszustand B1,
• 1b die Prinzipskizze eines Bildschirms in einer ersten Ausgestaltung im Betriebszustand B2,
• 2a die Prinzipskizze eines Bildschirms in einer zweiten Ausgestaltung im Betriebszustand B1,
• 2b die Prinzipskizze eines Bildschirms in einer zweiten Ausgestaltung im Betriebszustand B2,
• 3a die Prinzipskizze eines Bildschirms in einer dritten Ausgestaltung im Betriebszustand B1,
• 3b die Prinzipskizze eines Bildschirms in einer dritten Ausgestaltung im Betriebszustand B2,
• 4a die Prinzipskizze eines Bildschirms in einer vierten Ausgestaltung im Betriebszustand B1,
• 4b die Prinzipskizze eines Bildschirms in einer vierten Ausgestaltung im Betriebszustand B2,
• 5a die Prinzipskizze eines Bildschirms in einer fünften Ausgestaltung im Betriebszustand B1,
• 5b die Prinzipskizze eines Bildschirms in einer fünften Ausgestaltung im Betriebszustand B2,
• 5c die Prinzipskizze eines Bildschirms in einer siebenten Ausgestaltung,
• 6 die Prinzipskizze zur Ausgestaltung eines statischen Barriereschirms, sowie
• 7 die Prinzipskizze zur Verschachtelung zweier Bildinhalte.

The invention is explained in more detail below with reference to drawings, which also show features that are essential to the invention. It shows

• 1 a the schematic diagram of a screen in a first embodiment in the operating state B1,
• 1b the schematic diagram of a screen in a first embodiment in operating state B2,
• 2a the schematic diagram of a screen in a second embodiment in operating state B1,
• 2 B the schematic diagram of a screen in a second embodiment in operating state B2,
• 3a the schematic diagram of a screen in a third embodiment in operating state B1,
• 3b the schematic diagram of a screen in a third embodiment in operating state B2,
• 4a the schematic diagram of a screen in a fourth embodiment in the operating state B1,
• 4b the schematic diagram of a screen in a fourth embodiment in operating state B2,
• 5a the schematic diagram of a screen in a fifth embodiment in operating state B1,
• 5b the schematic diagram of a screen in a fifth embodiment in operating state B2,
• 5c the basic sketch of a screen in a seventh embodiment,
• 6 the basic sketch for the design of a static barrier screen, as well as
• 7 the basic sketch for nesting two image contents.

The drawings are not true to scale and merely provide schematic representations. In addition, for reasons of clarity, only a small selection of light beams are generally shown in each case, although in reality there is a veritable large number of them.

• - einen transmissiven Bildgeber 2, vorzugsweise ein LCD-Panel, einschließlich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten auf dem Bildgeber 2,
• - eine Hintergrundbeleuchtung 4,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung 4 angeordnete flächig ausgedehnte Komponente 3 mit Abschnitten 3a und optional Abschnitten 3b, welche auf sie einfallendes Licht in jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittieren,
• - Mittel zur Umschaltung zwischen den Betriebsarten B1 und B2.

It shows 1a the schematic diagram of a screen in a first embodiment in the operating state B1 and 1b in operating state B2. The screen 1, which can be operated in at least two operating modes B1 for a free view mode and B2 for a restricted angle or a dual view mode, comprises

• - a transmissive imager 2, preferably an LCD panel, including an electronic control for the defined display of image content on the imager 2,
• - a backlight 4,
• - an extensive component 3 arranged in the viewing direction in front of the backlight 4 and having sections 3a and optionally sections 3b, which transmit light incident on them in each case with a transmittance that can be selected between a minimum value and a maximum value,
• - Means for switching between the operating modes B1 and B2.

In principle, any type of LCD technology such as the types IPS, VA or TN or others can be used as the LCD panel for the image generator 2 . It is supportive for the limited angular ranges and also for the dual viewing mode if the imager 2 has the smallest possible volume scattering in order to fan out directed light penetrating the imager 2 as little as possible or only slightly by scattering. "Slight" means, for example, that - due to the low Haze scattering value - at a relative angle of, for example, 40° horizontally from the surface normal, a maximum of 1% of the luminance is added by scattering, which causes the background lighting in the direction of the peak luminance ( e.g. a horizontal angle of 0°). The color sub-pixel sizes of an LCD panel are typically in the range of a few to tens of micrometers. However, the invention is by no means tied to this. Electronic controls for LCD panels and backlighting are well known in the prior art and do not require any further discussion here.

The extensive component 3 arranged in front of the backlight 4 in the viewing direction can be both in front of and behind ter the image generator 2 can be used. For the considerations mentioned below, it should be regarded as lying behind the image generator 2 without restricting the generality. Sections 3a and possibly 3b of extensive component 3, which transmit light incident on them with a selectable transmittance between a minimum value and a maximum value, can correspond in their area approximately to the area of a pixel or a subpixel of image generator 2. However, the size of the area of sections 3a, 3b is preferably the corresponding size of entire clusters of pixels, so that a section 3a, 3b covers a defined number of pixels of the imager in the case of parallel projection along the perpendicular bisector of the imager 2. For example, it can be a matter of rectangular sections 3a, 3b, which in said parallel projection are approximately 5×5, 10×5, 5×10, 20×20, 30×30, 10×20, 20×10, 50× Cover 50, 100×50 or 50×100 pixels. Other surface sizes and/or shapes of sections 3a and 3b are possible.

The transmittance of the respective sections 3a of the two-dimensionally extended component 3 are particularly preferably controlled as a function of the image content displayed on the imager 2, in particular by said electronic control of the imager 2. The purpose of the two-dimensionally extended component 3 with the sections 3a is therefore based on the transmittance that can be set locally is in particular to improve the perceptible image contrast by using a local dimming approach. For example, in the case of dark parts of an image content, the corresponding sections 3a can be driven with a low transmittance, while in the case of light parts of an image content, the corresponding sections 3a are driven with a high transmittance.

Corresponding approaches for local dimming are often described in the prior art (e.g. in the documents WO 2021/015710 A1 , TW 201503095 A or KR 20120063940 A ) and are therefore not mentioned in detail here.

The two-dimensionally extended component 3 can, for example, comprise a liquid crystal panel with polarizers in order to achieve the defined local dimming, ie the setting of degrees of transmission. One of the polarizers of the two-dimensionally extended component 3 can, for example in the case of an LCD panel as imager 2, also form a polarizer of the LCD panel.
The component 3 extending over a surface area can thus preferably be configured as a module together with the imager 2 .
Other configurations of the extensive component 3 are of course possible, for example using electrochromism, electro-wetting, electrophoresis, magnetophoresis or other technical-optical operating principles.
Depending on the configuration, the degrees of transmission that can be achieved in sections 3a (when measured with white-mixed light perpendicular to the surface) are generally between <0.001% and 50% or more.

In one in the 1a and 1b In the first embodiment of the screen 1 shown, the means for switching between the operating modes B1 and B2 are implemented in that a prism grid and/or a lenticular grid and/or a barrier screen 5 with a transparent-opaque pattern with a period P is arranged so that when a single image content B is displayed on the image generator 2 in the operating mode B1, this can be perceived from a wide angular range W1 (ie greater than 60 degrees laterally), and so that when two image contents L that are periodically interlaced are displayed, R on the imager 2 in operating mode B2 for a dual viewing mode, in which the period PB of the interlaced image contents L, R when displayed on the imager 2 corresponds to the said period P up to a maximum tolerance of three percent, the image contents L, R can be perceived predominantly from different angular ranges W2, W3.
In this context, the term "predominantly" means that a complete channel separation of the angle ranges W2 and W3 is technically practically impossible to achieve and therefore there is a certain overlap, albeit small, also known as "crosstalk", of the angle ranges W2 and W3. Typically, the luminance in such overlapping areas is a maximum of 3% of the maximum peak luminance shown in each of the angular areas. For example, an image content shown in angle range W2 with 100% peak luminance could be visible at a maximum of 3% of the peak luminance in angle range W3. However, the degree of overlap is preferably less than 3%, in particular at most 1% or at most 0.5%.

The optical design of the prism grid, the lenticular grid or the barrier screen 5 with a transparent-opaque pattern, each with a period P, is familiar to the person skilled in the art and is done in particular taking into account the desired angular ranges W2 and W3, the dimensions (and positions) of the pixels of the image generator 2, in particular the period PB in the interlacing of the image contents L, R, the period P, the refractive indices involved (e.g. for prism or lens grids, cover glass of the LCD panel) and the general geometric positional conditions. the 7 shows the simplified basic sketch for nesting two image contents. Each box in the plot ment then corresponds, depending on the configuration, to a full-color pixel, a color sub-pixel or simultaneously to a plurality of color sub- or full-color pixels.

It is advantageous here if, in operating mode B2 for a dual viewing mode, the respective period limits of the prism grid, the lenticular grid or the barrier screen 5 coincide with the period limits of the respective two image contents L, R that are periodically interleaved in one another on the image generator 2 in the case of parallel projection, with the exception of one Tolerance of a maximum of 300 μm, preferably a maximum of 100 μm, match.

The advantage of this first configuration compared to the prior art lies in particular in the fact that an image perception that is enhanced in contrast due to the two-dimensionally extended component 3 can be presented both in a dual-view mode and in a public viewing mode. The implementation, for example, with a prism grid 5 and a liquid crystal panel with polarizers, that is to say a component that is extended over a large area, can be implemented inexpensively.

Furthermore shows 2a the schematic diagram of a screen in a second embodiment in the operating state B1 and 2 B in operating state B2. In this second embodiment of the screen 1, the means for switching between the operating modes B1 and B2 are implemented in that the backlighting 4 can switch between at least two operating modes B1 and B2, with the backlighting 4 in operating mode B1 emitting light in an -off direction Observer's horizontally measured angular range W1 of more than 60 degrees, so that when a single image content B is displayed on the image generator 2 in the operating mode B1, this can be perceived from a wide angular range W1 (which is laterally greater than 60 degrees), and where the background lighting 4 in the operating mode B2 emits light in a narrow angular range W2 of less than 60 degrees, measured horizontally from the direction of an observer, with residual light of a maximum of five percent (preferably a maximum of 1 or 2 percent) of the peak Luminance is disregarded, so when depicting a a Zigen image content B on the imager 2 in the operating mode B2 this is only perceptible from a limited angular range W2. For technical reasons, as described above, a few percent of light (measured at the peak luminance in the angular range W2) can still be emitted outside of the angular range W2. This residual light should be as small as possible in order to offer a viewer outside the angular range W2 an image that is as imperceptible as possible or at least barely perceptible.
Exemplary configurations of a corresponding backlight 4 are described, inter alia, in the documents EP 3 570 097 A1 , U.S. 10,712,488 B2 , US 10,838,133 B2 such as EP 3552056 B1 the applicant.
In addition, the background lighting 4 in the operating mode B1 or B2 can also have a disruptive light distribution (ie with two or more peaks), as long as the desired visibility conditions can be achieved with the aforementioned angular ranges W1 or W2.
The advantages of this second embodiment compared to the prior art are the use of local dimming approaches to increase contrast in screens that can be switched in the angle range of the radiation, with the integration of the extensive component 3 with the image generator 2 as a module being a cost-effective and effective design embody.

Furthermore there 3a the schematic diagram of a screen in a third embodiment in the operating state B1 and 3b in operating state B2 again. In this third embodiment of the screen 1, the means for switching between the operating modes B1 and B2 are implemented in that in the operating mode B1, in which all sections 3a of the two-dimensionally extended component 3 have a selectable transmittance (in particular depending on the on the imager 2 shown image content, as already described above) and when a single image content B is displayed on the image generator 2, this can be perceived from a wide angular range W1 (i.e. more than 60 degrees laterally), and that when two periodically interlaced image contents L , R on the imager 2 in the operating mode B2 for a dual viewing mode, in which the areally extended component 3 represents an opaque pattern of a barrier screen with the period PD on a real selection of sections 3b and on the complementary selection of sections 3a one each selectable transmittance, and in which the period PB of the interlaced image contents L, R when displayed on the image generator 2 corresponds to the said period PD up to a maximum tolerance of three percent, the said image contents L, R are each predominantly perceived from different angular ranges W2, W3 be able.
"Real" selection of sections 3a or 3b means that not all sections are selected at the same time, and at the same time not no section either.

Said opaque pattern of a barrier screen means that the selection of sections 3b is switched to the minimum transmittance, while the sections 3a of the areally extended component 3 that are complementary thereto have a selectable transmittance, which before is determined via the local dimming mechanisms mentioned above.
The comments made above on the term “predominantly” also apply here. The advantages of this third embodiment compared to the prior art are in particular the enabling of a high-contrast display, which can be displayed either in a wide angular range or in a dual-view mode in two (apart from the "crosstalk") disjoint angular ranges. In principle, even more than two angle ranges are possible, for example for a “triple view” design.
Furthermore, the contrast is particularly high in the dual-view mode, because the selection of opaque sections 3b ensures reduced dark values in the luminance in any case and independent of the image content, while the maximum values of the luminance are basically achieved by the sections 3a, which can be adjusted in terms of transmittance.
A particularly outstanding means-effect relationship here is that the contrast-enhancing layer, ie the two-dimensionally extended component 3, is also responsible for the light direction-selective effect, ie for the optical generation of the angle ranges, in the dual-view mode.

• - wobei in jedem Takt T1, T2 zwei ineinander periodisch verschachtelte Bildinhalte L, R auf dem Bildgeber 2 wiedergegeben werden und die Verschachtelung der Bildinhalte L, R zwischen den Takten T1, T2 alterniert,
• - wobei ferner die flächig ausgedehnte Komponente 3 auf einer echten Auswahl an Abschnitten 3b (d.h. mit minimalem Transmissionsgrad) ein opakes Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären Auswahl an Abschnitten 3a einen jeweils wählbaren Transmissionsgrad umsetzt und dabei zwischen den Takten T1, T2 die genannten Auswahlen an Abschnitten 3a, 3b alternieren,
• - und bei dem die Periode PB der verschachtelten Bildinhalte L, R bei Darstellung auf dem Bildgeber 2 jeweils bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt,
• - so dass die besagten Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 und im zeitlichen Mittel in der vollen Auflösung des Bildgebers 2 wahrgenommen werden können.

the 4a shows the schematic diagram of a screen in a fourth embodiment in the operating state B1 and 4b in operating state B2. In this fourth embodiment of the screen 1, which is based on the third embodiment, in the operating mode B2 for a dual viewing mode, at least two clocks T1, T2 are implemented periodically one after the other,

• - wherein in each cycle T1, T2 two periodically interlaced image contents L, R are reproduced on the image generator 2 and the interlacing of the picture contents L, R alternates between the cycles T1, T2,
• - Wherein the areally extended component 3 represents an opaque pattern of a barrier screen with the period PD on a real selection of sections 3b (i.e. with minimum transmittance) and on the complementary selection of sections 3a converts a respectively selectable transmittance and thereby between the clocks T1, T2 the named selections alternate at sections 3a, 3b,
• - and in which the period PB of the interlaced image contents L, R when displayed on the image generator 2 corresponds to the said period PD up to a maximum tolerance of three percent,
• - So that said image content L, R can be perceived predominantly from different angular ranges W2, W3 and on average over time in the full resolution of the imager 2.

This fourth embodiment can be switched over for operating mode B1 by using all sections 3a, 3b of component 3 as sections 3a, ie converting a respectively selectable transmittance. At the same time, only image content B would then be shown on image generator 2, as in 3a shown. The above definition of the word “predominantly” also applies here. The advantages of this fourth embodiment compared to the third embodiment are, in particular, the full-resolution representation of the image contents in different angular ranges over time, with a simultaneous increase in contrast.

• - wobei in der Betriebsart B1, in welcher alle Abschnitte 3a der flächig ausgedehnten Komponente 3 einen jeweils wählbaren Transmissionsgrad aufweisen, bei Darstellung eines einzigen Bildinhaltes B auf dem Bildgeber 2 dieser aus einem breiten Winkelbereich W1 (d.h. mehr als 60 Grad lateral) wahrnehmbar ist,
• - und wobei in der Betriebsart B2 für einen im Winkelbereich eingeschränkten Sichtmodus, in welcher die flächig ausgedehnte Komponente 3 auf einer echten Auswahl an Abschnitten 3b ein opakes (d.h. mit minimalem Transmissionsgrad) Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären Auswahl an Abschnitten 3a einen jeweils wählbaren Transmissionsgrad umsetzt, wobei ferner die Periode PF bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt, so dass bei Darstellung eines einzigen Bildinhaltes B auf dem Bildgeber 2 dieser lediglich aus einem eingeschränkten Winkelbereich W2 wahrnehmbar ist.

Furthermore there 5a the schematic diagram of a screen in a fifth embodiment in the operating state B1 and 5b in operating state B2 again. In this fifth embodiment of a screen 1, the means for switching between the operating modes B1 and B2 are implemented in that a static barrier screen 6 with a transparent-opaque pattern with a period PF is also arranged in front of the backlight 4 in the viewing direction,

• - wherein in the operating mode B1, in which all sections 3a of the two-dimensionally extended component 3 have a selectable transmittance, when a single image content B is displayed on the image generator 2, this can be perceived from a wide angular range W1 (ie more than 60 degrees laterally),
• - and in the operating mode B2 for a viewing mode limited in the angular range, in which the areally extended component 3 represents an opaque (i.e. with minimal transmittance) pattern of a barrier screen with the period PD on a real selection of sections 3b and on the selection complementary thereto converts a selectable transmittance in sections 3a, with the period PF also matching said period PD up to a maximum tolerance of three percent, so that when a single image content B is displayed on the image generator 2, this can only be perceived from a limited angular range W2 .

The above definition of “predominantly” also applies here.
The static barrier screen 6 can be arranged in front of the backlight 4 in the viewing direction, but behind the two-dimensionally extended component 3, or behind the imager 2 or in front of the imager 2.
6 gives a basic sketch for the design of a static barrier screen. The period PF is clearly evident. In principle, opaque-to-transparent duty ratios other than the 1:4 ratio shown here are also possible, for example 1:1, 1:2, 1:3, 1:5 or even higher.

The advantages of this fifth embodiment compared to the prior art are, in particular, the even higher contrast achieved due to the static barrier, which is already significantly and dynamically increased by the extensive component 3 compared to the achievable contrast of the individually used imager 2, with switching between a wide and a narrow angle range is made possible.

• - einen transmissiven Bildgeber 2, vorzugsweise ein LCD-Panel, einschließlich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten L, R auf dem Bildgeber 2,
• - eine Hintergrundbeleuchtung 4,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung 4 angeordnete flächig ausgedehnte Komponente 3, deren Abschnitte 3a auf sie einfallendes Licht in jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittieren,
• - ein Prismenraster und/oder ein Linsenraster und/oder einen Barriereschirm 5 mit einem transparent-opaken Muster mit einer Periode P, welches bzw. welcher vor oder hinter dem Bildgeber 2 angeordnet ist, so dass bei Darstellung zweier ineinander periodisch verschachtelter Bildinhalte L, R auf dem Bildgeber 2 in der Betriebsart B2 für einen dualen Sichtmodus, bei dem die Periode PB der verschachtelten Bildinhalte L, R bei Darstellung auf dem Bildgeber 2 bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode P übereinstimmt, die Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 wahrgenommen werden können.

A sixth embodiment of the screen 1, which can be operated in at least one dual view mode, is described below with reference to FIG 1b explained. The corresponding screen 1 includes

• - a transmissive imager 2, preferably an LCD panel, including an electronic control for the defined display of image content L, R on the imager 2,
• - a backlight 4,
• - an extensive component 3 arranged in the viewing direction in front of the backlight 4, the sections 3a of which transmit light incident on it in each case with a transmittance that can be selected between a minimum value and a maximum value,
• - a prism grid and/or a lenticular grid and/or a barrier screen 5 with a transparent-opaque pattern with a period P, which is arranged in front of or behind the image generator 2, so that when two periodically interlaced image contents L, R on the imager 2 in operating mode B2 for a dual viewing mode, in which the period PB of the interlaced image contents L, R when displayed on the imager 2 corresponds to the said period P up to a maximum tolerance of three percent, the image contents L, R can each be perceived predominantly from different angular ranges W2, W3.

The above description of the word "predominantly" also applies here. The two-dimensionally extended component 3 can in turn be arranged in front of the backlight 4 and at the same time in front of or behind the imaging device 2 in the viewing direction.

In principle, it should be noted here that the image contents L and R can differ, but can also be the same. In the case of equality, different viewers who are in the different angular ranges see the same image content.

The explanations given above for the first embodiment regarding the size of the sections 3a also apply here by analogy. The advantage of this sixth embodiment compared to the prior art lies in particular in the fact that an image perception that is enhanced in terms of contrast due to the two-dimensionally extended component 3 can also be presented in a dual-view mode. The implementation, for example, with a prism grid 5 and a liquid crystal panel with polarizers, that is to say a component that is extended over a large area, can be implemented inexpensively.

• - einen transmissiven Bildgeber 2, vorzugsweise ein LCD-Panel, einschließlich einer elektronischen Ansteuerung zur definierten Darstellung von Bildinhalten L, R auf dem Bildgeber 2,
• - eine Hintergrundbeleuchtung 4,
• - eine in Betrachtungsrichtung vor der Hintergrundbeleuchtung 4 angeordnete flächig ausgedehnte Komponente 3, welche auf sie einfallendes Licht in Abschnitten 3a, 3b jeweils mit einem zwischen einem Minimalwert und einem Maximalwert wählbaren Transmissionsgrad transmittiert,
• - ein in Betrachtungsrichtung vor der Hintergrundbeleuchtung 4 angeordneter statischer Barriereschirm 6 mit einem transparent-opaken Muster mit einer Periode PF,
• - wobei zyklisch, d.h. zeitlich periodisch, die flächig ausgedehnte Komponente 3 auf einer ersten und einer zweiten echten Auswahl an Abschnitten 3b abwechselnd ein opakes (d.h. mit minimalem Transmissionsgrad) Muster eines Barriereschirms mit der Periode PD darstellt und auf der dazu komplementären ersten und zweiten Auswahl an Abschnitten 3a einen jeweils wählbaren Transmissionsgrad umsetzt, wobei ferner die Periode PF bis auf eine Toleranz von maximal drei Prozent mit der besagten Periode PD übereinstimmt, wobei die Bildinhalte L, R auch zyklisch, d.h. in derselben zeitlichen Periode, wie die Abschnitte 3a und 3b ihre Positionen wechseln, dargestellt werden, so dass im zeitlichen Mittel die Bildinhalte L, R jeweils überwiegend aus unterschiedlichen Winkelbereichen W2, W3 wahrgenommen werden.

Finally can 5b can also be used as a schematic diagram of a screen in a seventh embodiment in a first cycle, while 5c shows the schematic diagram of a screen in a seventh embodiment in the complementary cycle. A seventh embodiment of the screen 1, which can be operated in at least one dual viewing mode, includes

• - a transmissive imager 2, preferably an LCD panel, including an electronic control for the defined display of image content L, R on the imager 2,
• - a backlight 4,
• - an extensive component 3 arranged in the viewing direction in front of the backlight 4, which transmits light incident on it in sections 3a, 3b, each with a transmittance that can be selected between a minimum value and a maximum value,
• - a static barrier screen 6 arranged in front of the backlight 4 in the viewing direction and having a transparent-opaque pattern with a period PF,
• - Wherein cyclically, ie periodically periodic in time, the areally extended component 3 alternately represents an opaque (ie with minimum transmittance) pattern of a barrier screen with the period PD on a first and a second real selection of sections 3b and on the first and second selection complementary thereto converts a selectable transmittance in sections 3a, with the period PF also matching said period PD up to a maximum tolerance of three percent, with the image contents L, R also cyclically, ie in the same time period as sections 3a and 3b her posi Change functions are displayed, so that on average over time, the image contents L, R are perceived predominantly from different angular ranges W2, W3.

The above explanation of "predominantly" also applies here.

The two-dimensional component 3 arranged in front of the backlight 4 in the viewing direction can be located in front of or behind the imaging device.
Furthermore, the explanations given for the first embodiment regarding the size of sections 3a and 3b also apply here. The sections 3a can each transmit light with a transmittance that can be selected between a minimum value and a maximum value in order to improve the contrast locally using a local dimming approach. The static barrier screen 6 can be arranged in front of the backlight 4 in the viewing direction, but behind the two-dimensionally extended component 3, or behind the imager 2 or in front of the imager 2.
If no opaque sections 3b are provided in this embodiment in a further mode, but only sections 3a that can be freely selected in transmission, then imaging in a wide angle range is also possible, comparable to the operating mode B1 of the fifth embodiment.
The advantages of this seventh embodiment compared to the prior art are, in particular, that with simple and inexpensive means, namely a static barrier and an extensive component, an excellent image contrast is achieved, which clearly exceeds the image contrast of the image generator, while at the same time due to the timing of the sections a dual-view mode is achieved on the extensive component.

Of course, all image content B, L, R in all configurations can be still images and/or moving images, text or other visual content.

In the first, third, fourth, sixth and seventh configuration of the screen 1, in which in operating mode B2 for a dual viewing mode image content L, R can be perceived predominantly from different angular ranges W2, W3, one of the angular ranges W2 or W3 preferably closes such a half-plane, which runs through the center of the image area of the imager 2, is at the same time perpendicular to the image area of the imager 2 and at the same time is aligned parallel to the left edge of the image area of the imager 2, at least partially.

For all configurations, the two-dimensionally extended component 3 allows the implementation of a local dimming approach to increase the contrast without having to make the backlighting locally dimmable. This is another advantage over the prior art.

The invention also includes the use of a screen 1 according to one of the seven design variants described above in a vehicle, with the vehicle driver in operating mode B2 not perceiving any or only image content with a maximum of two percent (residual light) of the peak brightness in the viewing mode limited in the angular range, or , in the case of a dual viewing mode, perceives a different image content L than a person traveling with you who sees the image content R.
A motor vehicle, a ship, an airplane or a spacecraft can generally be considered here as a vehicle.
In the case of the dual-view display, there is also the option of superimposing the image content R actually displayed for the person traveling with you, which could also be visible to the vehicle driver as residual light, with a lighter image content L for the vehicle driver. The lighter image content L means, for example, a light static image (eg a gray or colored area). Because of this cross-fading, it can be ensured that the driver of the vehicle actually does not perceive any of the image content R that is not intended for him. A visual disturbance to the driver by image content R intended for the person traveling with him is thus avoided in any case.

In addition, depending on the dimensioning of the different angular ranges, it is fundamentally possible in all of the aforementioned configurations with a dual view mode (dual view) to achieve a glasses-free three-dimensional display when displaying stereoscopic content as image content L, R. For this purpose, the angular ranges must adjoin one another in such a way that the eyes of one or possibly several viewers each see a different image content L, R.

The optical elements described above solve the problem: a screen was described which enables the defined viewing of image content from predeterminable angular ranges, with the highest possible image contrast being achieved at the same time. The invention can be implemented inexpensively.

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 at ATMs or payment terminals or to enter a password or when reading emails and secret documents on mobile devices. As described above, the invention can also be used in passenger cars.

Claims (13)

Screen (1) which can be operated in at least two operating modes B1 for a free view mode and B2 for a restricted angle or a dual view mode, comprising - a transmissive imager (2) including an electronic control for the defined display of image content on the imager (2), - a backlight (4), - an extensive component (3) arranged in the viewing direction in front of the backlight (4) and having sections (3a) which transmit light incident on it with a transmittance that can be selected between a minimum value and a maximum value, with the transmittances of the respective sections (3a ) of the two-dimensionally extended component (3) depending on the image content displayed on the image generator (2), - Means for switching between the operating modes B1 and B2. screen (1) after claim 1 , characterized in that the extensive component (3) is arranged in the viewing direction behind the imager (2) and is preferably formed with this as a module. screen (1) after claim 1 or 2 , characterized in that the areally extended component (3) comprises a liquid crystal panel with polarizers. Screen (1) according to one of the preceding claims, characterized in that the means for switching between the operating modes B1 and B2 are implemented in that a prism grid and/or a lenticular grid and/or a barrier screen ( 5) is arranged with a transparent-opaque pattern with a period (P), so that when a single image content (B) is displayed on the imager (2) in the operating mode B1, this can be perceived from a wide angular range W1, and so that when two periodically interlaced image contents (L, R) are displayed on the imager (2) in operating mode B2 for a dual viewing mode, in which the period (PB) of the interlaced image contents (L, R) when displayed on the imager (2) up to a maximum tolerance of three percent with said period (P), the image contents (L, R) can be perceived predominantly from different angular ranges (W2, W3). Screen (1) after one of Claims 1 until 3 , characterized in that the means for switching between the operating modes B1 and B2 are implemented in that the backlight (4) can switch between at least two operating modes B1 and B2, the backlight (4) in the operating mode B1 light in a -off The angular range (W1) measured horizontally in the direction of an observer is more than 60 degrees, so that when a single image content (B) is displayed on the image generator (2) in operating mode B1, this can be perceived from a wide angular range (W1), and wherein the background lighting (4) in operating mode B2 light is emitted in an angular range (W2) of less than 60 degrees, measured horizontally from the direction of an observer, with residual light of a maximum of five percent of the peak Luminance is not taken into account, so that when a single image content (B) is displayed on the imager (2) in the operating mode B2 di it can only be perceived from a limited angle range (W2). Screen (1) after one of Claims 1 until 3 , characterized in that the means for switching between the operating modes B1 and B2 are implemented in that in the operating mode B1, in which all sections (3a) of the two-dimensionally extended component (3) have a selectable transmittance and when a single image content is displayed (B) on the imager (2) this can be perceived from a wide angle range (W1), and that when two periodically interlaced image contents (L, R) are displayed on the imager (2) in the operating mode B2 for a dual viewing mode which the areally extended component (3) represents an opaque pattern of a barrier screen with the period (PD) on a real selection of sections (3b) and implements a selectable transmittance on the complementary selection of sections (3a), and in which the Period (PB) of the interlaced image content (L, R) when displayed on the image generator (2) up to a maximum tolerance of three percent coincides with said period PD, said image contents (L, R) can be perceived predominantly from different angular ranges (W2, W3). screen (1) after claim 6 , characterized in that in operating mode B2 for a dual viewing mode, at least two cycles (T1, T2) are periodically implemented one after the other, - wherein in each clock (T1, T2) two periodically interlaced image contents (L, R) are reproduced on the image generator (2) and the interlacing of the image contents (L, R) alternates between the clocks (T1, T2), - wherein furthermore, the two-dimensionally extended component (3) represents an opaque pattern of a barrier screen with the period (PD) on a real selection of sections (3b) and on the selection of sections (3a) complementary thereto converts a selectable transmittance between the clocks (T1, T2) the named selections of sections (3a, 3b) alternate, - and in which the period PB of the interlaced image contents (L, R) when displayed on the image generator (2) has a maximum tolerance of three percent of the said period (PD), - so that the said image contents (L, R) are perceived predominantly from different angular ranges (W2, W3) and on average over time in the full resolution of the image generator (2). can ground. Screen (1) after one of Claims 1 until 3 , characterized in that the means for switching between the operating modes B1 and B2 are implemented in that a static barrier screen (6) with a transparent-opaque pattern with a period (PF) is also arranged in front of the background lighting (4) in the viewing direction, - wherein in operating mode B1, in which all sections (3a) of the two-dimensionally extended component (3) have a selectable transmittance, when a single image content (B) is displayed on the image generator (2), this can be perceived from a wide angle range (W1). - and wherein in the operating mode B2 for a viewing mode limited in the angular range, in which the areally extended component (3) on a real selection of sections (3b) represents an opaque pattern of a barrier screen with the period (PD) and on the to complementary selection of sections (3a) converts a selectable degree of transmittance, with the period (PF) up to a T tolerance of a maximum of three percent corresponds to said period (PD), so that when a single image content (B) is displayed on the image generator (2), it can only be perceived from a limited angular range (W2). A screen (1) operable in at least one dual view mode, comprising - a transmissive imager (2) including an electronic control for the defined display of image content (L, R) on the imager (2), - a backlight (4), - an extensive component (3) arranged in the viewing direction in front of the backlight (4) and having sections (3a) which transmit light incident on it with a transmittance that can be selected between a minimum value and a maximum value, the transmittances of the respective sections (3a ) of the two-dimensionally extended component (3) depending on the image content displayed on the image generator (2), - A prism grid and/or a lenticular grid and/or a barrier screen (5) with a transparent-opaque pattern with a period (P), which is arranged in front of or behind the image generator (2), so that when two are displayed one inside the other periodically interlaced image content (L, R) on the image generator (2) in operating mode B2 for a dual viewing mode in which the period (PB) of the interlaced image content (L, R) when displayed on the image generator (2) up to a tolerance of a maximum of three percent with said period (P), the image contents (L, R) can be perceived predominantly from different angular ranges (W2, W3). Screen (1) that can be operated in at least one dual viewing mode, comprising - a transmissive image generator (2) including an electronic control for the defined display of image content (L, R) on the image generator (2), - a backlight (4 ), - an extensive component (3) arranged in the viewing direction in front of the backlight (4) and having sections (3a) which transmit light incident on it in sections (3a) with a transmittance that can be selected between a minimum value and a maximum value, with the transmittances of the respective sections (3a) of the two-dimensionally extended component (3) are controlled depending on the respective image content displayed on the image generator (2), - a static barrier screen (6) with a transparent-opaque pattern arranged in front of the background lighting (4) in the viewing direction with a period (PF), - whereby cyclically, ie periodically in time, the flat out expanded component (3) represents an opaque pattern of a barrier screen with the period (PD) on a first or second real selection of sections (3b) and on the complementary first or second selection of sections (3a) converts a respective selectable transmittance, wherein furthermore, the period (PF) corresponds to said period (PD) up to a maximum tolerance of three percent, and wherein the picture contents (L, R) also cyclically, ie in the same time period as the sections (3a, 3b) their position change functions, are displayed so that the image contents (L, R) are perceived predominantly from different angular ranges (W2, W3) on average over time. Screen (1) after one of Claims 4 , 6 , 7 , 9 or 10 , characterized in that in operating mode B2 for a dual viewing mode, the two said image contents (L, R) can each be perceived predominantly from different angular ranges (W2, W3), one of the angular ranges (W2 or W3) having such a half-plane, the runs through the center of the area of the image area of the imager (2), is perpendicular to the image area of the imager (2) and at the same time is aligned parallel to the left edge of the image area of the imager (2), at least partially encloses. Screen (1) according to one of the preceding claims, characterized in that the transmissive image generator (2) is an LCD panel. Use of a screen (1) according to one of the preceding claims in a vehicle, in which case the driver of the vehicle in operating mode B2, in the viewing mode restricted in the angular range, perceives no or only image content with a maximum of two percent of the peak brightness, or, in the case of a dual viewing mode, perceives a different image content (L) than a person traveling with you who sees the image content (R).

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