Directional display device

Abstract

A switchable privacy display includes a spatial light modulator (SLM), a first switchable liquid crystal (LC) retarder and a first passive retarder between a first pair of polarizers, and a second switchable LC retarder and a second passive retarder between a second pair of polarizers. The first switchable LC retarder includes a homeotropic alignment layer and a planar alignment layer. The second switchable LC retarder includes either two homeotropic alignment layers or two planar alignment layers. In a landscape or portrait privacy mode, on-axis light from the SLM is directed without loss, while off-axis light has reduced luminance to reduce visibility to off-axis snoopers. Display reflectivity can be reduced for on-axis reflection of ambient light, while reflectivity can be increased for off-axis light to achieve increased visual security. In a public mode, the LC retardance is adjusted so that off-axis luminance and reflectivity are unchanged. The display can be switched between daytime and nighttime operation.

Description

Technical Field

[0001] This disclosure generally relates to illumination from a light modulation device, and more specifically to an optical stack for providing illumination control in a display including a privacy display and a night display. Background Technology

[0002] Privacy displays provide image visibility for the primary user, typically in a coaxial position, and reduced visibility of the image content for a spy, typically in an off-axis position. Privacy functionality can be provided using micro-visor optical films that allow some light from the display to pass through in the coaxial direction, while providing low brightness in the off-axis position. However, such films exhibit high losses for front illumination, and the micro-visors can cause moiré artifacts due to pixel jumps with the spatial light modulator. The spacing of the micro-visors may also need to be selected based on the panel resolution, increasing inventory and cost.

[0003] Switchable privacy displays can be provided via control of off-axis optical output.

[0004] Control can be provided by means of brightness reduction, for example by means of a switchable backlight for a spatial light modulator used in a liquid crystal display (LCD). Display backlights typically employ waveguides and edge-emitting sources. Some imaging-oriented backlights have the additional ability to guide illumination through the display panel into the viewing window. The imaging system can be formed between multiple sources and their respective window images. An example of an imaging-oriented backlight is an optical valve that can employ a folded optical system, and therefore can also be an example of a folded imaging-oriented backlight. Light can propagate through the optical valve substantially without loss in one direction, while light propagating in the opposite direction can be extracted by reflection from a tilted facet, as described in U.S. Patent No. 9,519,153, which is incorporated herein by reference in its entirety. Summary of the Invention

[0005] According to a first aspect of this disclosure, a display device is provided, comprising: a spatial light modulator; a display polarizer disposed on one side of the spatial light modulator, the display polarizer being a linear polarizer; a first additional polarizer disposed on the same side of the spatial light modulator as the display polarizer, the first additional polarizer being a linear polarizer; at least one first pole control delay unit disposed between the first additional polarizer and the display polarizer; a second additional polarizer being a linear polarizer; and at least one second pole control delay unit, wherein either: the second additional polarizer is disposed on the same side of the spatial light modulator as the first additional polarizer and outside the first additional polarizer, and at least one second pole control delay unit is disposed between the first additional polarizer and the second additional polarizer; or the display device further comprises a backlight source disposed for outputting light, the spatial light modulator comprising a transmissive spatial light modulator disposed for receiving output light from the backlight source, the display polarizer being an input display polarizer disposed on the input side of the spatial light modulator, and the display device further comprising a backlight source disposed on the input side of the spatial light modulator. An output display polarizer is provided on the output side of a spatial light modulator. A second additional polarizer is arranged on the output side of the spatial light modulator, and at least one second pole control delay is arranged between the second additional polarizer and the output display polarizer. Each of the at least one first pole control delay and the at least one second pole control delay includes a respective switchable liquid crystal delay. The switchable liquid crystal delay includes a liquid crystal material layer and two surface alignment layers. The two surface alignment layers are arranged adjacent to the liquid crystal material layer and on opposite sides of the liquid crystal material layer. Regarding one of the at least one first pole control delay and the at least one second pole control delay, one of the surface alignment layers is arranged to provide a homogeneous alignment in the adjacent liquid crystal material, and the other of the surface alignment layers is arranged to provide a homeotropic alignment in the adjacent liquid crystal material. Regarding the other of the at least one first pole control delay and the at least one second pole control delay, both surface alignment layers are arranged to provide a homogeneous alignment in the adjacent liquid crystal material, or both surface alignment layers are arranged to provide a homeotropic alignment in the adjacent liquid crystal material. Advantageously, the switchable privacy display can be provided with extended polar regions, on which the desired level of security can be achieved.

[0006] A switchable liquid crystal retarder comprising at least one of a first-pole controlled retarder and at least one second-pole controlled retarder can have a delay for light with a wavelength of 550 nm, the delay having a first delay value in the range of 700 nm to 2500 nm, preferably in the range of 850 nm to 1800 nm. Advantageously, the brightness on the desired polar region can be reduced; in embodiments including a reflective polarizer, the reflectivity on the wide polar region can be increased and the security level can be provided at the desired level on the wide polar region.

[0007] One of the at least one first-pole control delay unit and the at least one second-pole control delay unit may further include at least one passive compensation delay unit. Advantageously, the area of ​​reduced brightness can be increased. Furthermore, the uniformity of brightness in the common mode can be improved.

[0008] The spatial light modulator may include an emitting spatial light modulator arranged to output light, an output display polarizer arranged on the output side of the emitting spatial light modulator, a second additional polarizer arranged on the output side of the spatial light modulator outside the first additional polarizer, and at least one second pole control delay unit arranged between the first and second additional polarizers. Advantageously, a switchable privacy display with a high security factor may be provided for the emitting spatial light modulator.

[0009] The display device may further include a backlight arranged to output light, and the spatial light modulator may include a transmissive spatial light modulator arranged to receive the output light from the backlight. Advantageously, a switchable privacy display with a high security factor can be provided for the transmissive spatial light modulator.

[0010] At least one passive compensation retarder of at least one of the first-pole controlled retarder and at least one second-pole controlled retarder can be arranged on the same side of the switchable liquid crystal retarder as the surface alignment layer arranged to provide vertical alignment in the adjacent liquid crystal material. At least one passive compensation retarder of at least one of the first-pole controlled retarder and at least one second-pole controlled retarder can include a passive uniaxial retarder having an optical axis perpendicular to the plane of the retarder. The passive uniaxial retarder can have a delay in the range of -400 nm to -2100 nm, preferably in the range of -700 nm to -1700 nm, for light with a wavelength of 550 nm. Advantageously, the size of the polar region is increased for the desired level of security.

[0011] The display device may further include a reflective polarizer, which is a linear polarizer, and or: the display polarizer may be an output display polarizer arranged on the output side of the spatial light modulator, a second additional polarizer may be arranged on the same side of the spatial light modulator as the first additional polarizer, outside the first additional polarizer, at least one second pole control delay unit may be arranged between the first additional polarizer and the second additional polarizer, and the reflective polarizer may be arranged between the first additional polarizer and at least one second pole control delay unit; or the display device may further include a backlight arranged to output light, the spatial light modulator may include a transmissive spatial light modulator arranged to receive output light from the backlight, the display polarizer may be an input display polarizer arranged on the input side of the spatial light modulator, and the display device may further include an output display polarizer arranged on the output side of the spatial light modulator, a second additional polarizer may be arranged on the output side of the spatial light modulator, at least one second pole control delay unit may be arranged between the second additional polarizer and the output display polarizer, and the reflective polarizer may be arranged between the output display polarizer and at least one second pole control delay unit. Advantageously, enhanced display reflectivity can be provided in privacy operating mode. Under ambient light conditions, an enhanced security level for the display can be achieved targeting the location of potential snoops.

[0012] The first of at least one first-pole control delay unit and the second of at least one second-pole control delay unit may be at least one second-pole control delay unit, and the other of at least one first-pole control delay unit and the second of at least one second-pole control delay unit may be at least one first-pole control delay unit.

[0013] A switchable liquid crystal retarder comprising at least one of a first-pole controlled retarder and at least one of a second-pole controlled retarder may have a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the other of the at least one first-pole controlled retarder and at least one of a second-pole controlled retarder may also have a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value. The magnitude of the difference between half of the first delay value and the second delay value may be at most 400 nm. The first-pole controlled retarder and the second-pole controlled retarder may provide brightness reduction and reflection increase for different polar regions. Advantageously, the polar region on which the desired visual safety is achieved is enlarged.

[0014] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, both surface alignment layers can be arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 450 nm to 900 nm, preferably in the range of 550 nm to 800 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a pair of passive single-axis retarders having intersecting optical axes in the plane of the retarder, and each having a delay of light with a wavelength of 550 nm in the range of 250 nm to 800 nm, preferably in the range of 400 nm to 625 nm. Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers may be arranged to provide uniform alignment in adjacent liquid crystal materials having a delay in the range of 500 nm to 900 nm (preferably 600 nm to 850 nm) for light with a wavelength of 550 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder may further include a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay in the range of -300 nm to -700 nm, preferably in the range of -350 nm to -600 nm, for light with a wavelength of 550 nm. Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers can be arranged to provide a vertical alignment in adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm. The other of the at least one first-pole controlled retarder and at least one second-pole controlled retarder can further include a passive uniaxial retarder having an optical axis perpendicular to the plane of the retarder and having a retardation of light with a wavelength of 550 nm in the range of -300 nm to -900 nm, preferably in the range of -400 nm to -800 nm. Advantageously, high brightness reduction and reflection can be achieved for the polar region complementary to the brightness reduction of one of the at least one first-pole controlled retarder and at least one second-pole controlled retarder. The level of security can be improved, and the size of the polar region for the desired visual security can be increased.

[0015] The spatial light modulator may include an emitting spatial light modulator arranged to output light, an output display polarizer arranged on the output side of the emitting spatial light modulator, a second additional polarizer arranged on the output side of the spatial light modulator outside the first additional polarizer, and at least one second pole control delay unit arranged between the first and second additional polarizers. Advantageously, the emitting display can be provided with a desired level of security within a desired polar angle range.

[0016] The emitted spatial light modulator can have an output brightness profile with a full width at half maximum (FWHM) of at least 40 degrees, preferably at least 50 degrees. Advantageously, the common operating mode can provide high image visibility over a wide polar angle range.

[0017] The display device may further include a backlight arranged to output light, and the spatial light modulator may include a transmissive spatial light modulator arranged to receive the output light from the backlight. The backlight may have an output brightness profile having a full width at half maximum (FWHM) of at least 40 degrees, preferably at least 50 degrees.

[0018] A switchable liquid crystal delay device of at least one of a first-pole controlled delay device and at least one of a second-pole controlled delay device may have a delay for light with a wavelength of 550 nm, the delay having a first delay value, and a switchable liquid crystal delay device of at least one of a first-pole controlled delay device and at least one of a second-pole controlled delay device may have a delay for light with a wavelength of 550 nm, the delay having a second delay value, half of the first delay value being less than the second delay value. Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers may be arranged to provide uniform alignment in adjacent liquid crystal materials having a delay of 700 nm to 2500 nm, preferably in the range of 850 nm to 1800 nm, for light with a wavelength of 550 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder may further comprise a pair of passive uniaxial retarders having intersecting optical axes in the plane of the retarders, and each having a delay of 600 nm to 1600 nm, preferably in the range of 750 nm to 1300 nm, for light with a wavelength of 550 nm. Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers can be arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 700 nm to 2500 nm, preferably in the range of 1000 nm to 1800 nm, and the other of the at least one first-pole controlled retarder and at least one second-pole controlled retarder can further include a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay of light with a wavelength of 550 nm in the range of -700 nm to -2500 nm, preferably in the range of -900 nm to -1800 nm. Advantageously, a switchable privacy display can be provided to achieve a narrow privacy switch-on angle.

[0019] The spatial light modulator may include an emitting spatial light modulator arranged to output light, a display polarizer may be an output display polarizer arranged on the output side of the emitting spatial light modulator, a second additional polarizer may be arranged on the output side of the spatial light modulator, outside the first additional polarizer, and at least one second-pole control delay unit may be arranged between the first and second additional polarizers. The emitting spatial light modulator may include a pixel array arranged in a pixel layer, and the display device may further include a parallax barrier forming an array of apertures, wherein the parallax barrier is spaced apart from the pixel layer by a parallax distance along an axis normal to the plane of the pixel layer, and each pixel is aligned with the aperture. The emitting spatial light modulator and the parallax barrier may have an output brightness profile having a full width at half maximum (FWHM) of up to 40 degrees. Advantageously, a switchable privacy display can provide an enhanced level of security for off-axis spying locations. The emitting display may be provided to operate in privacy mode for both landscape and portrait modes.

[0020] The display device may include a backlight arranged to output light, and the spatial light modulator may include a transmissive spatial light modulator arranged to receive the output light from the backlight. The backlight may have an output brightness profile having a full width at half maximum (FWHM) of up to 40 degrees. Advantageously, privacy displays can be provided for transmissive displays. The backlight may be provided with a reduced cone angle. The polar region for the desired security level may be enlarged.

[0021] The display polarizer can be an input display polarizer arranged on the input side of the spatial light modulator; a first additional polarizer can be arranged between the backlight and the input display polarizer; and a second additional polarizer can be arranged on the same side of the spatial light modulator as the first additional polarizer, between the backlight and the first additional polarizer, and at least one second-pole control delay unit can be arranged between the first and second additional polarizers. Advantageously, the visibility of frontal reflections from the front surface of the display device can be reduced.

[0022] The surface alignment layer of at least one of the first-pole control delayers and at least one of the second-pole control delayers may have a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a first pair of antiparallel directions, and the surface alignment layer of the other of the at least one first-pole control delayer and at least one of the second-pole control delayers may have a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a second pair of antiparallel directions, the first pair of antiparallel directions intersecting the second pair of antiparallel directions. Viewed from the plane of the liquid crystal material layer orthogonal to at least one first-pole control delayer and at least one second-pole control delayer, the first pair of antiparallel directions and the second pair of antiparallel directions may form a 90-degree angle. Advantageously, the polar region with the desired security level can be implemented in both the lateral and elevation directions. Switchable privacy displays can be provided in both landscape and portrait orientations. In automotive use, reflections from the windshield can be reduced.

[0023] A switchable liquid crystal retarder comprising at least one of a first-pole controlled retarder and at least one of a second-pole controlled retarder may have a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the other of the at least one first-pole controlled retarder and at least one of a second-pole controlled retarder may have a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value. The magnitude of the difference between half of the first delay value and the second delay value is at most 400 nm. Advantageously, the size of the polar region for the desired security level is increased.

[0024] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers may be arranged to provide uniform alignment in adjacent liquid crystal materials having a delay of 450 nm to 900 nm, preferably 550 nm to 800 nm, for light with a wavelength of 550 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further comprises a pair of passive single-axis retarders having intersecting optical axes in the plane of the retarders, and each having a delay of 250 nm to 800 nm, preferably 400 nm to 625 nm, for light with a wavelength of 550 nm. With respect to the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers may be arranged to provide uniform alignment in adjacent liquid crystal materials having a delay of 550 nm wavelength in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder may further include a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder and having a delay of 550 nm wavelength in the range of -300 nm to -700 nm, preferably in the range of -350 nm to -600 nm. With respect to the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers may be arranged to provide a vertical alignment in adjacent liquid crystal materials having a delay of 550 nm wavelength in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder may further include a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder and having a delay of 550 nm wavelength in the range of -300 nm to -800 nm, preferably in the range of -400 nm to -800 nm.

[0025] The spatial light modulator may include an emitting spatial light modulator arranged to output light, an output display polarizer arranged on the output side of the emitting spatial light modulator, a second additional polarizer arranged on the output side of the spatial light modulator outside the first additional polarizer, and at least one second pole control delay unit arranged between the first and second additional polarizers. The other of the at least one first pole control delay unit and the at least one second pole control delay unit may further include at least one passive compensation delay unit.

[0026] At least one passive compensation retarder of the other of at least one first pole-controlled retarder and at least one second pole-controlled retarder may include a passive single-axis retarder having its optical axis perpendicular to the plane of the retarder. Advantageously, thickness and cost can be reduced. Advantageously, when the pole-controlled retarder further includes two vertical orientation layers, the pole region on which the desired level of security is achieved is increased.

[0027] At least one passive compensation retarder of the other of at least one first pole-controlled retarder and at least one second pole-controlled retarder may comprise a pair of passive single-axis retarders having intersecting optical axes in the plane of the retarder. Advantageously, when the pole-controlled retarder further comprises two planar orientation layers, the pole region on which the desired level of security is achieved is increased.

[0028] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers can be arranged to provide vertical alignment in adjacent liquid crystal materials. Advantageously, power consumption is reduced in the common operating mode.

[0029] The display device may further include a backlight arranged to output light, a spatial light modulator including a transmissive spatial light modulator arranged to receive the output light from the backlight, and the other of at least one first-pole controlled delay unit and at least one second-pole controlled delay unit may be located between the backlight and the transmissive spatial light modulator. The thickness of the components arranged in front of the display is reduced. Increased front surface diffuser can provide low pixel blur, increased image fidelity, and reduced visibility of specular reflections.

[0030] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, the two surface alignment layers can be arranged to provide surface alignment in adjacent liquid crystal materials. Advantageously, the visibility of artifacts can be reduced under applied pressure. The pole region can be enlarged for the desired level of security.

[0031] Any aspect of this disclosure may be applied in any combination.

[0032] The embodiments of this disclosure can be used in a variety of optical systems. The embodiments can include, or work with, various projectors, projection systems, optical components, displays, microdisplays, computer systems, processors, self-contained projector systems, visual and / or audiovisual systems, and electrical and / or optical devices. Aspects of this disclosure can be used with virtually any device associated with optical devices and electrical devices, optical systems, presentation systems, or any device that may contain any type of optical system. Therefore, embodiments of this disclosure can be used in optical systems, devices used in visual presentation and / or optical presentation, visual peripherals, and various computing environments.

[0033] Before proceeding with a detailed discussion of the disclosed embodiments, it should be understood that this disclosure is not limited to the details of the specific arrangement shown in its application or creation, as other embodiments of this disclosure are possible. Furthermore, aspects of this disclosure can be described in different combinations and arrangements to define their own unique embodiments. In addition, the terminology used herein is for descriptive purposes and not for limitation.

[0034] These and other advantages and features of this disclosure will become apparent to those skilled in the art upon full reading of this disclosure. Attached Figure Description

[0035] The implementation scheme is illustrated by way of example in the accompanying drawings, in which similar reference numerals indicate similar parts, and in the accompanying drawings:

[0036] Figure 1A The diagram is a side perspective view illustrating a switchable privacy display for use in ambient lighting. The switchable privacy display includes an emitting spatial light modulator, a first pole control delay arranged between a display polarizer and a first additional polarizer of the emitting spatial light modulator, and a reflective polarizer and a second pole control delay arranged between the first additional polarizer and a second additional polarizer.

[0037] Figure 1B The illustration in the front perspective view is used for Figure 1A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme;

[0038] Figure 1C Illustration in side perspective view Figure 1A A schematic diagram of a switchable privacy display, in which the reflective polarizer is omitted and the first additional polarizer is a reflective polarizer;

[0039] Figure 2The illustration in the side perspective view is used to illustrate the purpose of... Figure 1A A schematic diagram of alternative structures for the spatial light modulator used in the arrangement, the alternative structures further including a parallax barrier;

[0040] Figure 3 The illustration in the side perspective view is used to illustrate the purpose of... Figure 1A A schematic diagram of alternative structures for the spatial light modulator used in the arrangement, including a transmission spatial light modulator and a backlight.

[0041] Figure 4A This is a side perspective view illustrating a switchable privacy display for use in ambient lighting. The switchable privacy display includes... Figure 3 The transmission spatial light modulator and backlight, the reflection polarizer and the first pole control delay arranged between the output display polarizer and the first additional polarizer of the spatial light modulator, and the second pole control delay arranged between the input display polarizer and the second additional polarizer of the spatial light modulator.

[0042] Figure 4B The illustration in the front perspective view is used for Figure 4A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme;

[0043] Figure 5A This is a side perspective view illustrating a switchable privacy display, which includes... Figure 3 The transmission spatial light modulator and backlight, the first pole control delay unit arranged between the input display polarizer and the first additional polarizer of the spatial light modulator, and the second pole control delay unit arranged between the first additional polarizer and the second additional polarizer.

[0044] Figure 5B The illustration in the front perspective view is used for Figure 1A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme;

[0045] Figure 6A This is a schematic diagram illustrating the structure of a polarity control retarder in a side perspective view. The polarity control retarder includes a passive C-plate and an active liquid crystal layer including a vertical alignment layer and a horizontal alignment layer. The pretilt angle direction of the alignment layer has an antiparallel component in the plane of the alignment layer, and the component is oriented in a first direction in the plane of the alignment layer.

[0046] Figure 6B This is a schematic diagram illustrating the structure of a polarity control retarder in a side perspective view. The polarity control retarder includes a passive C-plate and an active liquid crystal layer including two surface alignment layers, wherein the pretilt angle direction of the alignment layers has an antiparallel component in the plane of the alignment layers.

[0047] Figure 6C This is a side perspective view illustrating the structure of the polarity control retarder and a schematic diagram of an active liquid crystal layer including two planar alignment layers, wherein the polarity control retarder includes intersecting A plates;

[0048] Figure 6D This is a schematic diagram illustrating the structure of a polarity control retarder in a side perspective view. The polarity control retarder includes a passive C-plate and an active liquid crystal layer including two vertical alignment layers, wherein the pretilt angle direction of the alignment layers has an antiparallel component in the plane of the alignment layers.

[0049] Figure 6E This is a side perspective view illustrating the structure of the polarity control retarder and a schematic diagram of an active liquid crystal layer including two planar alignment layers, wherein the polarity control retarder includes intersecting A plates;

[0050] Figure 7A It is illustrated in the side view. Figure 1A A schematic diagram of the operation of transmitted light from the spatial light modulator in the common operating mode;

[0051] Figure 7B It is illustrated in the side view. Figure 1A A schematic diagram illustrating the operation of ambient light in the public operation mode;

[0052] Figure 7C It is illustrated in the side view. Figure 1A A schematic diagram of the arrangement in privacy operation mode to operate transmitted light from the spatial light modulator with the high reflectivity of ambient light;

[0053] Figure 7D It is illustrated in the side view. Figure 1A A schematic diagram of the arrangement of ambient light in privacy operation mode using the high reflectivity of ambient light;

[0054] Figure 8A The illustration in the front perspective view is used for Figure 1A A schematic diagram of the arrangement of polarizers and pole control retarders in the implementation scheme, wherein the first pole control retarder includes a vertical alignment layer and a surface alignment layer and a C plate; and the second pole control retarder includes two surface alignment layers and intersecting A plates;

[0055] Figure 8B This is a graph illustrating the analog polar profile of the brightness output of the transmitting spatial light modulator.

[0056] Figure 8C The diagram illustrates the arrangement between the first and second additional polarizers. Figure 8AThe simulated polar coordinate curve of the transmission of the second pole controlled delay is shown in the figure, where the electric vector transmission direction of the polarizer is parallel.

[0057] Figure 8D The diagram illustrates the arrangement between the reflective polarizer and the second additional polarizer. Figure 8A The simulated polar coordinate curve of the reflectivity of the second-pole controlled retarder is plotted, where the electric vector transmission direction of the polarizer is parallel.

[0058] Figure 8E This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 8D The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device;

[0059] Figure 8F The illustration shows the arrangement between the display polarizer and the first additional polarizer. Figure 8A The simulated polar coordinate curve of the transmission of the first pole control delay is plotted, where the electric vector transmission direction of the polarizer is parallel and the pretilt direction of the first pole control delay is parallel or antiparallel to the pretilt direction of the second pole control delay.

[0060] Figure 8G This is a diagram. Figure 8A A graph of the logarithmic polar coordinates of the total output brightness of the spatial light modulator, the first-pole control delay unit, and the second-pole control delay unit.

[0061] Figure 8H This illustration shows the ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits. Figure 8A A graph of the simulated polar coordinate curve of the safety level S of the layout;

[0062] Figure 8I This illustration shows the ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits. Figure 8A A graph of the simulated lateral curve of the visual security factor at zero elevation angle for the arrangement;

[0063] Figure 8J This illustration shows the ambient illuminance, measured in lux, as twice the brightness of a front-facing display, measured in nits and operating in common mode. Figure 8A A graph of the simulated polar coordinate curve of the safety level S of the layout;

[0064] Figure 9AThis is a graph illustrating the simulated polar coordinate curve of the brightness output of a transmissive spatial light modulator illuminated by a collimated backlight source.

[0065] Figure 9B This is a graph illustrating the simulated polar coordinate curves of the transmission of the second-stage control delayer.

[0066] Figure 9C This is a graph illustrating the simulated polar coordinate curve of the reflectivity of the second-stage control delay device.

[0067] Figure 9D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 9C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device;

[0068] Figure 9E This is a graph illustrating the simulated polar coordinate curves of the transmission of the first-stage control delay, where the pretilt direction of the first-stage control delay is parallel to or antiparallel to the pretilt direction of the second-stage control delay.

[0069] Figure 9F This is a graph illustrating the logarithmic output brightness of the spatial light modulator, the first-pole controlled delay unit, and the second-pole controlled delay unit in analog polar coordinates.

[0070] Figure 9G This is a graph illustrating the simulated polar coordinate curve of the safety level S for an arrangement with ambient illuminance measured in lux, which is twice the brightness of the front display measured in nits.

[0071] Figure 9H This is a graph illustrating the simulated lateral curve of the visual safety factor for the arrangement at a zero-degree elevation angle, for ambient illuminance measured in lux, which is twice the brightness of the front display measured in nits.

[0072] Figure 9I This is a graph illustrating a simulated polar coordinate curve of the safety level S for ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits and operating in public mode.

[0073] Figure 10A This is a graph illustrating the simulated polar coordinate curve of the brightness output of a transmissive spatial light modulator illuminated by a collimated backlight source.

[0074] Figure 10B This is a graph illustrating the simulated polar coordinate curves of the transmission of the second-stage control delayer.

[0075] Figure 10CThis is a graph illustrating the simulated polar coordinate curves of the reflectivity of a second-pole controlled retarder without a reflective polarizer.

[0076] Figure 10D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 10C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device without a reflective polarizer;

[0077] Figure 10E This is a graph illustrating the simulated polar coordinate curves of the transmission of the first-stage control delay, where the pretilt direction of the first-stage control delay is parallel or antiparallel to the pretilt direction of the second-stage control delay.

[0078] Figure 10F This is a graph illustrating the logarithmic output brightness of the spatial light modulator, the first-pole controlled delay unit, and the second-pole controlled delay unit in analog polar coordinates.

[0079] Figure 10G This is a graph illustrating the simulated polar coordinate curve of the safety level S of an arrangement without a reflective polarizer, which is twice the ambient illuminance measured in lux, and is measured in nits as the brightness of the front display.

[0080] Figure 10H This is a graph illustrating the simulated lateral curve of the visual safety factor at a zero-degree elevation angle for an arrangement with ambient illuminance measured in lux, which is twice the brightness of the frontal display measured in nits.

[0081] Figure 11A This is a graph illustrating the simulated polar coordinate curve of the brightness output of a transmissive spatial light modulator illuminated by a collimated backlight source.

[0082] Figure 11B This is a graph illustrating the simulated polar coordinate curves of the transmission of the second-stage control delayer.

[0083] Figure 11C This is a graph illustrating the simulated polar coordinate curve of the reflectivity of the second-pole controlled delay.

[0084] Figure 11D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 11C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device;

[0085] Figure 11E This is a graph illustrating the simulated polar coordinate curves of the transmission of the first-pole controlled delay, where the pretilt angle direction of the first-pole controlled delay is orthogonal to the pretilt angle direction of the second-pole controlled delay;

[0086] Figure 11F This is a graph illustrating the logarithmic output brightness of the spatial light modulator, the first-pole controlled delay unit, and the second-pole controlled delay unit in analog polar coordinates.

[0087] Figure 11G This is a diagram illustrating the meaning of... Figure 11A -F is a graph of the simulated polar coordinate curve of the safety level S of an arrangement without a reflective polarizer, which is twice the ambient illuminance measured in lux and is the brightness of the front display measured in nits.

[0088] Figure 12A It is a diagrammatic illustration with Figure 2 A graph of the simulated polar coordinate curve of the brightness output of the emission spatial light modulator with a barrier structure;

[0089] Figure 12B This diagram illustrates the light emitted from the pixels of the spatial light modulator. Figure 2 A graph of the simulated polar coordinate curves of the transmission of the barrier structure;

[0090] Figure 12C This is a graph illustrating the simulated polar coordinates of the transmission of a second-pole controlled delay unit arranged between a first and a second additional polarizer, where the electric vector transmission directions of the polarizers are parallel.

[0091] Figure 12D This is a graph illustrating the simulated polar coordinate curve of the reflectivity of a second-pole controlled delay unit arranged between a reflective polarizer and a second additional polarizer, where the electric vector transmission direction of the polarizer is parallel.

[0092] Figure 12E It is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes reflectance and Fresnel reflectance from the front surface of the display device;

[0093] Figure 12F It is a graph illustrating the simulated polar coordinate curve of the transmission of a first pole control delay unit arranged between the display polarizer and the first additional polarizer, wherein the electric vector transmission direction of the polarizer is parallel.

[0094] Figure 12G This is a graph illustrating the logarithmic output brightness of the spatial light modulator, the first-pole controlled delay unit, and the second-pole controlled delay unit in analog polar coordinates.

[0095] Figure 12HThis is a graph illustrating the simulated polar coordinate curve of the safety level S for an arrangement with ambient illuminance measured in lux, which is twice the brightness of the front display measured in nits.

[0096] Figure 12I The diagram illustrates that the first-stage control delay unit is... Figure 12H The second-pole control delay and the second-pole control delay is Figure 12H A graph of the simulated polar coordinate curve of the safety level S of the first-stage control delay;

[0097] Figure 12J This is a graph illustrating the simulated polar coordinate curve of the safety level S for an arrangement with ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits and operating in common mode.

[0098] Figure 13 This is a side perspective view illustrating a switchable privacy display assembly for use with a spatial light modulator, which includes a first pole control delay unit and a first additional polarizer, a reflective polarizer, and a second pole control delay unit disposed between the first additional polarizer and the second additional polarizer.

[0099] Figure 14 It is about Figure 15A -F、 Figure 16A -F、 Figure 17A -C and Figure 18A Illustration of alternative stacking arrangements for -F;

[0100] Figure 15A , Figure 15B , Figure 15C , Figure 15D , Figure 15E and Figure 15F The diagram in the side view illustrates an alternative stack of optical components for a switchable privacy display, wherein a first pole control delay unit and a second pole control delay unit are arranged to receive light from a transmission spatial light modulator and a backlight.

[0101] Figure 16A , Figure 16B , Figure 16C , Figure 16D , Figure 16E and Figure 16F The diagram in the side view illustrates an alternative stack of optical components for a switchable privacy display, wherein one of the first and second pole control delay units is arranged to receive light from a spatial light modulator, and a transmission spatial light modulator is arranged to receive light from the other of the first and second pole control delay units and a backlight.

[0102] Figure 17A , Figure 17B and Figure 17C This is a side view illustration of an alternative stack of optical components for a switchable privacy display, wherein a transmissive spatial light modulator is arranged to receive light from a first-pole controlled delay unit, a second-pole controlled delay unit, and a backlight; and

[0103] Figure 18A , Figure 18B , Figure 18C , Figure 18D , Figure 18E and Figure 18F The diagram in the side view illustrates an alternative to the stack of optical components for a switchable privacy display, wherein a first pole control delay unit and a second pole control delay unit are arranged to receive light from an emitting spatial light modulator. Detailed Implementation

[0104] The terminology associated with optical retarders used for the purposes of this disclosure will now be described.

[0105] In a layer comprising a uniaxial birefringent material, there exists a direction that controls optical anisotropy, and all directions perpendicular to it (or at a given angle to it) have equivalent birefringence.

[0106] The optical axis of an optical retarder refers to the direction of light propagation in a uniaxial birefringent material in which light does not undergo birefringence. This differs from the optical axis of an optical system, which can be, for example, parallel or perpendicular to the line of symmetry along which the principal ray propagates.

[0107] For light propagating in a direction orthogonal to the optical axis, the optical axis is the slow axis when linearly polarized light with an electric vector direction parallel to the slow axis propagates at the slowest speed. The slow axis direction is the direction with the highest refractive index at the designed wavelength. Similarly, the fast axis direction is the direction with the lowest refractive index at the designed wavelength.

[0108] For a positively dielectric anisotropic uniaxial birefringent material, the slow axis is the unusual axis of the birefringent material. For a negatively dielectric anisotropic uniaxial birefringent material, the fast axis is the unusual axis of the birefringent material.

[0109] The terms half-wavelength and quarter-wavelength refer to the operation of the retarder with respect to a design wavelength λ0, which is typically between 500 nm and 570 nm. In this illustrative embodiment, unless otherwise specified, exemplary delay values ​​are provided for a wavelength of 550 nm.

[0110] A retarder provides a phase shift between the two perpendicular polarization components of a light wave incident upon it, and this phase shift is characterized by the relative phase quantity Γ it imparts to the two polarization components; the relative phase quantity Γ is related to the birefringence Δn and thickness d of the retarder by the following equation:

[0111] Γ=2.π.Δn.d / λ0 Equation 1.

[0112] In Equation 1, Δn is defined as the difference between the unusual refractive index and the ordinary refractive index, i.e.,

[0113] Δn=n e -n o Equation 2.

[0114] For a half-wave delayer, the relationship between d, Δn, and λ0 is chosen such that the phase shift between the polarization components is Γ = π. For a quarter-wave delayer, the relationship between d, Δn, and λ0 is chosen such that the phase shift between the polarization components is Γ = π / 2.

[0115] In this article, the term half-wave delayer generally refers to light propagating perpendicular to the delayer and perpendicular to the spatial light modulator.

[0116] Some aspects of light propagation through a transparent delayer between a pair of polarizers will now be described.

[0117] The polarization state (SOP) of light is described by the relative amplitude and phase shift between any two orthogonal polarization components. A transparent retarder does not change the relative amplitude of these orthogonal polarization components, but only their relative phase. Providing a net phase shift between the orthogonal polarization components changes the SOP, while maintaining the net relative phase maintains the SOP. In the present specification, SOP may be referred to as the polarization state.

[0118] Linear SOP has polarization components with non-zero amplitude and orthogonal polarization components with zero amplitude.

[0119] A linear polarizer allows transmission of a unique linear SOP (which has a linearly polarized component parallel to the electric vector transmission direction of the linear polarizer) and causes attenuation of light with different SOPs. The term "electric vector transmission direction" refers to the non-directional axis of the polarizer along which the electric vector of the incident light is transmitted, even though the transmitted "electric vector" always has an instantaneous direction. The term "direction" is commonly used to describe this axis.

[0120] An absorptive polarizer is a polarizer that absorbs one polarization component of incident light and allows a second orthogonal polarization component to be transmitted. An example of an absorptive linear polarizer is a dichroic polarizer.

[0121] A reflective polarizer is a polarizer that reflects one polarization component of incident light and transmits a second, orthogonally polarized component. An example of a reflective polarizer that is a linear polarizer is a multilayer polymer film stack (such as DBEF from 3M). TM or APF TM ) or wire grid polarizers (such as ProFlux from Moxtek) TM The reflective linear polarizer may further include cholesteric reflective material and a quarter-wave plate arranged in series.

[0122] A delayer positioned between a linear polarizer and a parallel linear analytical polarizer that does not introduce a relative net phase shift provides full transmission of light except for residual absorption within the linear polarizer.

[0123] The delayer provides a relative net phase shift between orthogonal polarization components by changing the SOP and provides attenuation at the analysis polarizer.

[0124] In this disclosure, "A plate" refers to an optical retarder utilizing a birefringent material layer, wherein the optical axis is parallel to the plane of the layer.

[0125] "Positive A-plate" refers to a positive birefringent A-plate, that is, an A-plate with positive Δn.

[0126] In this disclosure, "C-plate" refers to an optical retarder utilizing a birefringent material layer, wherein its optical axis is perpendicular to the plane of the layer. "Positive C-plate" refers to a positive birefringent C-plate, i.e., a C-plate with a positive Δn. "Negative C-plate" refers to a negative birefringent C-plate, i.e., a C-plate with a negative Δn.

[0127] "O-plate" refers to an optical retarder that utilizes a birefringent material layer, where its optical axis has a component parallel to the plane of the layer and a component perpendicular to the plane of the layer. "Positive O-plate" refers to a positive birefringent O-plate, that is, an O-plate with positive Δn.

[0128] An achromatic retarder can be provided, wherein the material of the retarder is provided to have a retardation Δn.d that varies with wavelength λ as follows:

[0129] Δn.d / λ=κ Equation 3

[0130] Where κ is essentially a constant.

[0131] Examples of suitable materials include modified polycarbonate from Teijin Films. As described below, an achromatic retarder can be provided in embodiments of this application to advantageously minimize color variation between polar viewing directions with low brightness reduction and polar viewing directions with increased brightness reduction.

[0132] Various other terms related to delayers and liquid crystals as used in this disclosure will now be described.

[0133] The liquid crystal cell has a delay given by Δn.d, where Δn is the birefringence of the liquid crystal material in the liquid crystal cell, and d is the thickness of the liquid crystal cell, which is independent of the orientation of the liquid crystal material in the liquid crystal cell.

[0134] Planar alignment refers to the orientation of liquid crystals in a switchable liquid crystal display, where the molecules are oriented substantially parallel to the substrate. Planar alignment is sometimes referred to as planar alignment. Planar alignment can typically be provided with a small pretilt angle, such as 2 degrees, so that the molecules at the surface of the alignment layer of the liquid crystal cell are slightly tilted, as will be described below. The pretilt angle is arranged to minimize degeneracy during cell switching.

[0135] In this disclosure, vertical alignment is a state in which rod-shaped liquid crystal molecules are oriented substantially perpendicular to the substrate. In disc-shaped liquid crystals, vertical alignment is defined as a state in which the axis of the columnar structure formed by the disc-shaped liquid crystal molecules is perpendicular to the surface alignment. In vertical alignment, the pretilt angle is the tilt angle of the molecules near the alignment layer, and is typically close to 90 degrees, and can be, for example, 88 degrees.

[0136] In twisted liquid crystal layers, a twisted configuration (also known as a helical structure or spiral) of nematic liquid crystal molecules is provided. Twisting can be achieved by means of non-parallel alignment of the alignment layers. Furthermore, cholesteric dopants can be added to the liquid crystal material to disrupt the degeneracy of the twist direction (clockwise or counterclockwise) and further control the pitch of the twist in the relaxed (typically undriven) state. Super-twisted liquid crystal layers have twists greater than 180 degrees. Twisted nematic layers used in spatial light modulators typically have a twist of 90 degrees.

[0137] Liquid crystal molecules with positive dielectric anisotropy are switched from plane orientation (such as the A-plate retarder orientation) to vertical orientation (such as the C-plate or O-plate retarder orientation) by means of an applied electric field.

[0138] Liquid crystal molecules with negative dielectric anisotropy are switched from vertical orientation (such as the C-plate or O-plate retarder orientation) to plane orientation (such as the A-plate retarder orientation) by means of an applied electric field.

[0139] Rod-shaped molecules exhibit positive birefringence, such that, as described in Equation 2, n e >n o Disk-shaped molecules exhibit negative birefringence, such that n e <n o .

[0140] Positive retarders (such as A-plates, positive O-plates, and positive C-plates) are typically provided using stretched films or rod-shaped liquid crystal molecules. Negative retarders (such as negative C-plates) can be provided using stretched films or disk-shaped liquid crystal molecules.

[0141] Parallel liquid crystal cell alignment refers to the orientation direction of a plane-aligned layer that is parallel or more generally antiparallel. In the case of a pre-tilted vertical plane alignment, the alignment layer can have substantially parallel or antiparallel components. A mixed-alignment liquid crystal cell can have one plane-aligned layer and one vertical plane-aligned layer. A twisted liquid crystal cell can be provided by alignment layers that do not have parallel alignment (e.g., oriented at 90 degrees to each other).

[0142] The transmission spatial light modulator may further include a delay unit between the input display polarizer and the output display polarizer, such as that disclosed in U.S. Patent No. 8,237,876 (which is incorporated herein by reference in its entirety). Such a delay unit (not shown) is located in a different position than the passive delay unit of the embodiments of this application. This delay unit compensates for the contrast degradation at off-axis viewing locations, which is a different effect from the brightness reduction at off-axis viewing locations of the embodiments of this application.

[0143] A display's privacy operating mode is an operating mode where the observer sees a low contrast sensitivity, making the image less visible. Contrast sensitivity is a measure of the ability to distinguish different levels of brightness in a static image. Inverse contrast sensitivity can be used as a measure of visual security because a high visual security level (VSL) corresponds to low image visibility.

[0144] For a privacy display that provides images to an observer, visual security can be defined as follows:

[0145] V=(Y+R) / (Y–K) Equation 4

[0146] Where V is the Visual Security Level (VSL), Y is the brightness of the display in white at the peeper's viewing angle, K is the brightness of the display in black at the peeper's viewing angle, and R is the brightness of the reflected light from the display.

[0147] The panel contrast ratio is given as follows:

[0148] Equation 5: C = Y / K

[0149] Therefore, the visual security level can be further defined as:

[0150] V = (PY) 最大 +I.ρ / π) / (P.(Y 最大 -Y 最大 Equation 6

[0151] Where: Y 最大 P is the maximum brightness of the monitor; P is the off-axis relative brightness, which is usually defined as the brightness at the observer's angle relative to the maximum brightness Y. 最大The ratio of ρ to I; C is the image contrast ratio; ρ is the surface reflectance; and I is the illuminance. 最大 The unit is I divided by the unit of solid angle in steradian degrees.

[0152] The brightness of a monitor changes with the viewing angle, therefore the maximum brightness Y of the monitor... 最大 It occurs at a specific angle depending on the configuration of the monitor.

[0153] In many displays, the maximum brightness Y 最大 This occurs on the front, that is, perpendicular to the display. Any display device disclosed herein can be arranged to have a maximum brightness Y occurring on the front. 最大 In this case, for the maximum brightness Y of the display device 最大 The reference can be replaced with a reference to the brightness perpendicular to the display device.

[0154] Alternatively, any display described herein can be arranged to have a maximum luminance Y occurring at a polar angle greater than 0° with respect to the normal of the display device. 最大 For example, the maximum brightness Y 最大 This can occur at non-zero polar angles and at azimuth angles having, for example, zero lateral angles, so that maximum brightness is available for coaxial users looking down at the display device. The polar angle can be, for example, 10 degrees, and the azimuth angle can be north (90 degrees counterclockwise from east). The viewer can therefore expect to see high brightness at typical illegal viewing angles.

[0155] Off-axis relative brightness P is sometimes referred to as privacy level. However, such privacy level P describes the relative brightness of the display at a given polar angle compared to the front brightness, and is not actually a measure of privacy appearance.

[0156] Illuminance I is the luminous flux incident on the display and reflected from the display toward the observer's location per unit area. For Lambertian illumination, and for displays with Lambertian pre-diffuser illumination, illuminance I does not vary with polar and azimuth angles. For arrangements of displays in which non-Lambertian pre-diffuser illumination is placed in an environment with directional (non-Lambertian) ambient light, illuminance I varies with the polar and azimuth angles of observation.

[0157] Therefore, in a completely dark environment, a high-contrast display has a VSL of approximately 1.0. As ambient illuminance increases, the perceived image contrast decreases, the VSL increases, and privacy images become perceived.

[0158] For a typical LCD monitor, the panel contrast ratio C is greater than 100:1 for almost all viewing angles, which brings the visual safety level close to:

[0159] V = 1 + I.ρ / (π.PY) 最大 Equation 7.

[0160] In the current implementation, in addition to the exemplary definition in Equation 4, other measurements of the visual security level V may also be provided, such as those that include the image visibility to a spy at the spy's location, image contrast, image color and white point, and the effect on the size of opposing image features. Therefore, the visual security level can be a measure of the privacy level of the display, but is not limited to parameter V.

[0161] Perceived image security can be determined by the eye's logarithmic response, so that...

[0162] S = log 10 (V) Equation 8.

[0163] The expected limit for S is determined as follows. In the first step, a privacy display device is provided. The privacy level P(θ) of the display device as a function of the extreme viewing angle and the reflectivity ρ(θ) of the display device as a function of the extreme viewing angle are measured using a photometric apparatus. A light source, such as a lightbox with substantially uniform brightness, is arranged to provide illumination from the illuminated area, the illumination being arranged along the incident direction to illuminate the privacy display device for reflection to a viewer position at an extreme angle greater than 0° with respect to the normal of the display device. The illuminance I(θ) of a substantially Lambert-emitting lightbox as a function of the extreme viewing angle is determined by measuring the recorded reflected brightness as a function of the extreme viewing angle and taking into account the change in reflectivity ρ(θ). P(θ), r(θ), and I(θ) are used to determine the security factor S(θ) as a function of the extreme viewing angle along the zero elevation axis.

[0164] In the second step, a series of high-contrast images are provided on the privacy display, including (i) small text images with a maximum font height of 3mm, (ii) large text images with a maximum font height of 30mm, and (iii) moving images.

[0165] In the third step, each observer (with visual correction where appropriate, for viewing at 1000m) views each image from a distance of 1000m and adjusts their polar viewing angle at zero elevation until the image is invisible to one eye from a position near or close to the center line of the display. The polar coordinates of the observer's eye are recorded. From the relation S(θ), the safety factor at the polar coordinates is determined. For different images and for various display brightness Y... 最大 The measurements were repeated for different lightbox illuminance I (q = 0), different background lighting conditions, and different observers.

[0166] Based on the above measurements, S < 1.0 provides low visual security or no visual security, 1.0 ≤ S < 1.5 provides visual security that depends on the contrast, spatial frequency, and temporal frequency of the image content, 1.5 ≤ S < 1.8 provides image invisibility that is acceptable for most images and most observers (that is, the image contrast is not observable), and S ≥ 1.8 provides complete image invisibility, regardless of the image content for all observers.

[0167] In practical display devices, this means that it is desirable to provide an off-axis viewer, who is the voyeur, with a relationship S≥S 最小 The value of S, where: S 最小 A value of 1.0 or greater is used to achieve the effect that the displayed image is imperceptible to off-axis viewers; S 最小 A value of 1.5 or greater is used to achieve the effect that the displayed image is invisible to most images and most observers; that is, the viewer cannot even perceive that the image is being displayed; or S 最小 A value of 1.8 or greater is used to achieve the effect of making the displayed image invisible, regardless of the image content for all observers.

[0168] Compared to privacy displays, desired wide-angle displays are easily observed under standard ambient lighting conditions. One measure of image visibility is contrast sensitivity (such as Michelson contrast), which is given by the following equation:

[0169] M = (I 最大 –I 最小 ) / (I 最大 +I 最小 Equation 9

[0170] And therefore:

[0171] M=((Y+R)–(K+R)) / ((Y+R)+(K+R))=(YK) / (Y+K+2.R) Equation 10.

[0172] Therefore, the visual safety level (VSL) V is equal to 1 / M (but not the same as 1 / M). In this discussion, for a given off-axis relative luminance P, the wide-angle image visibility W is approximated as:

[0173] W = 1 / V = 1 / (1 + I.ρ / (π.PY)) 最大 Equation 11

[0174] The above discussion focuses on reducing the visibility of the displayed image to off-axis viewers (who are voyeurs), but similar considerations apply to the visibility of the displayed image to the intended users of the display device (who are typically coaxial). In this case, a reduction in the Visual Safety Level (VSL) corresponds to an increase in the visibility of the image to the viewer. During viewing, S < 0.1 can provide acceptable visibility of the displayed image. In practical display devices, this means that it is desirable to provide coaxial viewers (who are the intended users of the display device) with visibility satisfying the relationship S ≤ S 最大 The value of S, where S 最大 It has a value of 0.1.

[0175] In this discussion, the white point from the desired position (u) w ',v w The output color (u) w '+Δu',v w The color change Δε of (+Δv) can be determined using the CIELUV color difference metric (assuming a typical display spectrum emitter) and is given by the following equation:

[0176] Δε=(Δu' 2 +Δv' 2 ) 1 / 2 Equation 12.

[0177] The structure and operation of various directional display devices will now be described. In this description, common elements are designated by common reference numerals. It should be noted that the disclosure relating to any element applies to each device in which the same or corresponding elements are provided. Therefore, for the sake of brevity, such disclosures are not repeated.

[0178] Figure 1A This is a side perspective view illustrating a schematic diagram of a switchable privacy display device 100 for use in ambient lighting 604. The switchable privacy display device 100 includes an emitting spatial light modulator 48, a first pole control delay 300A disposed between a display polarizer 218 and a first additional polarizer 318A disposed between the emitting spatial light modulator 48, and a reflection polarizer 302 and a second pole control delay 300B disposed between the first additional polarizer 318A and a second additional polarizer 318B. Figure 1B The illustration in the front perspective view is used for Figure 1A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme.

[0179] The display device 100 includes a spatial light modulator 48; wherein the spatial light modulator 48 includes an emitting spatial light modulator 48 arranged to output light, and a display polarizer 218 is an output display polarizer arranged on the output side of the emitting spatial light modulator 48, and the display polarizer 218 is a linear polarizer.

[0180] A quarter-wave plate 202 is disposed between the display polarizer 218 and the pixel plane 214 to reduce front reflections from the pixel plane 214. Substrates 212 and 216 are disposed to provide support for the pixel plane 214.

[0181] The first additional polarizer 318A is arranged on the same side of the spatial light modulator 48 as the display polarizer 218. The first additional polarizer 318A is a linear polarizer. The first additional polarizer 318A is an absorptive polarizer, such as an iodine polarizer on stretched PVA.

[0182] At least one first pole control delay unit 300A is arranged between the first additional polarizer 318A and the display polarizer 218.

[0183] The display device 100 further includes a second additional polarizer 318B and at least one second pole control delay unit 300B, wherein the second additional polarizer is a linear polarizer. The second additional polarizer 318B is arranged on the output side of the spatial light modulator 48, outside the first additional polarizer 318A, and at least one second pole control delay unit 318B is arranged between the first additional polarizer 318A and the second additional polarizer 318B.

[0184] The display polarizer 218 is an output display polarizer arranged on the output side of the spatial light modulator 48, and the display device further includes a reflective polarizer 302 arranged between a first additional polarizer 318A and at least one second pole control delay unit 300B, the reflective polarizer being a linear polarizer.

[0185] Each of at least one first-pole controlled delay device 300A and at least one second-pole controlled delay device 300B includes a respective switchable liquid crystal delay device 301A, 301B, the switchable liquid crystal delay device 301A, 301B including liquid crystal material layers 314A, 314B respectively disposed between transparent substrates 312A, 312B and 316A, 316B.

[0186] Each of at least one first-pole control delay unit 300A and at least one second-pole control delay unit 300B further includes at least one passive compensation delay unit 330A, 330B, respectively.

[0187] In an alternative implementation (not shown), the reflective polarizer 302 can be omitted.

[0188] Figure 1C Illustration in side perspective view Figure 1A A schematic diagram of a switchable privacy display device 100 is provided, wherein the reflective polarizer 302 is omitted, and the first additional polarizer 318A is a reflective polarizer. Advantageously, thickness and cost can be reduced. Figure 1A Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0189] The spatial light modulator 48 can take any suitable form. Some possible alternatives are as follows.

[0190] Figure 2 The illustration in the side perspective view is for use in Figure 1A An alternative schematic diagram of the structure of the spatial light modulator 48 used in the arrangement is shown. The spatial light modulator 48 further includes a parallax barrier 700, which includes a light absorption region 704 and an aperture 702 aligned with pixels 220, 222, 224 of the pixel plane 214. The parallax barrier 700 is spaced apart from the pixel plane 214 by a distance d and aligned with the pixels so that the pixels have high brightness on the axis and reduced brightness off the axis.

[0191] In operation, the parallax barrier 700 is arranged to allow light 440 to pass from the pixel 224 in the normal direction to the spatial light modulator 48, and the aligned aperture 702 is arranged with an aperture size that provides high transmission. By comparison, light 442 tilted at a non-zero polar angle can be absorbed in the absorption region 704. A spacing d is provided to achieve minimum transmission at a desired polar angle in at least one azimuth direction. Advantageously, off-axis brightness is reduced, thereby achieving an improved safety factor.

[0192] Furthermore, when the incident ambient light is absorbed in the absorption region 704, the reflectivity of the pixel plane can be reduced. Figure 1A-1B The quarter-wave plate 202 can be omitted, thereby reducing cost and complexity.

[0193] Figure 2 Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0194] Now we will describe the use of in Figure 1A -B is an alternative to the emission spatial light modulator 48 used in the arrangement.

[0195] Figure 3 The illustration in the side perspective view is used to illustrate the purpose of... Figure 1AThe diagram illustrates an alternative structure for a spatial light modulator used in the arrangement, the alternative structure including a transmissive spatial light modulator 48 and a backlight 20 arranged to output light. The spatial light modulator 48 includes a transmissive spatial light modulator arranged to receive output light from the backlight 20. Figure 1A Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0196] The backlight may include a light guide plate (LGP) 1, a light extraction layer 5, and a rear reflector 3. The light extraction layer may include a diffuser, a light steering film, or a prism film. Light may be provided from a light source array (such as LEDs 15 arranged at the edge of the LGP 1).

[0197] The output can provide, for example, an intersecting BEF from 3M. TM The film achieves a wide-angle brightness curve and can have a full width at half maximum (FWHM) greater than 50 degrees. The output can provide a narrow-angle curve; such a backlight can be referred to as a collimated backlight and has a FWHM brightness of less than 50 degrees (e.g., 30 degrees). An example of a collimated backlight is illustrated in U.S. Patent No. 10,935,714, which is incorporated herein by reference in its entirety. The backlight can include other types of structures (including miniature LED arrays and known light distribution optics) to achieve the desired uniformity. The backlight 20 can be further provided with a miniature venetian blind array arranged to reduce the off-axis brightness output from the backlight 20. Advantageously, the safety factor S can be improved compared to a wide-angle backlight.

[0198] Alternative arrangements of the polarization control delay and the additional polarizer will now be described for a display device 100 including a backlight 20.

[0199] Figure 4A This is a side perspective view illustrating a schematic diagram of a switchable privacy display device 100 for use in ambient lighting 604. The switchable privacy display device 100 includes a transmissive spatial light modulator 48 and... Figure 3 The backlight 20; and Figure 4B The illustration in the front perspective view is used for Figure 4A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme.

[0200] The display device 100 further includes an input display polarizer 210 disposed on the input side of the spatial light modulator 48, and the display device 100 further includes an output display polarizer 218 disposed on the output side of the spatial light modulator 48. A first auxiliary polarizer 318A is disposed on the input side of the spatial light modulator 48, and a first pole control delay unit 300A is disposed between the first auxiliary polarizer 318A and the input display polarizer 210. A second auxiliary polarizer 318B is disposed on the output side of the spatial light modulator 48, and at least one second pole control delay unit 300B is disposed between the second auxiliary polarizer 318B and the output display polarizer 218.

[0201] The second pole control delay unit 300B is arranged between the input display polarizer 210 and the second additional polarizer 318B of the spatial light modulator 48. The reflection polarizer 302 is arranged between the output display polarizer 218 and the second pole control delay unit 318B. In an alternative embodiment (not shown), the reflection polarizer 302 may be omitted.

[0202] Advantageously, with Figure 1A Compared to the -B arrangement, the spacing of the second additional polarizer 318B at the output of pixel plane 214 is reduced. Due to the reduced number of layers, the contrast of the seen image can be improved. An air gap can be provided between the input polarizer 210 and the second pole delayer 300B, thereby advantageously reducing assembly costs and complexity.

[0203] In the current implementation, one of at least a first-pole control delayer 300A and at least a second-pole control delayer 300B is at least a second-pole control delayer, and the other of at least a first-pole control delayer and at least a second-pole control delayer is at least a first-pole control delayer.

[0204] Figure 4A Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0205] Figure 1A -B and Figure 4A The implementation can alternatively omit the reflective polarizer 302. Advantageously, frontal reflection is reduced in privacy mode in environments where increased reflection is considered undesirable. Another alternative arrangement without a reflective polarizer will now be described.

[0206] Figure 5A This is a schematic diagram illustrating a switchable privacy display device 100 in a side perspective view. The switchable privacy display device 100 includes a transmissive spatial light modulator 48 and... Figure 3The backlight 20; and Figure 5B The illustration in the front perspective view is used for Figure 1A A schematic diagram of the arrangement of the polarizer and the pole control delay in the implementation scheme.

[0207] The first pole control delay unit 300A is arranged between the input display polarizer 210 of the spatial light modulator 48 and the first additional polarizer 318A; and the second pole control delay unit 300B is arranged between the first additional polarizer 318A and the second additional polarizer 318B.

[0208] The reflective polarizer 302 is omitted. In some environments (such as certain automotive environments), reflective operation may be undesirable, and the reflectivity of the display's front surface can be reduced. Further cost reduction can be achieved.

[0209] With Figure 1 and Figure 4A Compared to the previous arrangement, the output display polarizer 218 is the output polarizer of the display device 100. Advantageously, a diffuser can be arranged on the polarizer 218 to provide improved image haze and reduced image blur. An air gap can be provided between the spatial light modulator input polarizer 210 and the multiple delayers 300A, 300B. Advantageously, image contrast is not reduced, and assembly costs and complexity are reduced.

[0210] Figure 5A Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0211] The method used in Figure 1 will now be described. Figure 4A and Figure 5A The arrangement of liquid crystal orientation used in delayers 300A and 300B.

[0212] Figure 6A This is a schematic diagram illustrating the structure of the polarity control retarder 300 in a side perspective view, wherein the polarity control retarder 300 includes a passive C-plate retarder 330 and an active liquid crystal layer 314.

[0213] Electrodes 413 and 415 are arranged to apply a voltage from the driver 350 across the entire liquid crystal material 421 in layer 314. In a first driven state, the liquid crystal molecules are arranged to provide no phase modification to the input polarization state in the normal direction of the polarization control retarder, but to provide modified phase to the input polarization state in a direction at an angle to the normal direction of the polarization control retarder 300. Such a driven state can be provided for privacy mode operation.

[0214] In the second driven state, the liquid crystal molecules are arranged to provide phase modification to the input polarization state in the normal direction of the polarization control retarder, but to provide phase modification to the input polarization state in a direction at an angle to the normal direction of the polarization control retarder 300. Such a driven state can be provided for common (or shared) mode operation.

[0215] Two surface alignment layers are configured to be adjacent to and on opposite sides of the liquid crystal material layer. One of the surface alignment layers is arranged to provide uniform alignment in the adjacent liquid crystal material, and the other surface alignment layer is arranged to provide vertical alignment in the adjacent liquid crystal material. The alignment layers thus include a vertical alignment layer 417A and a surface alignment layer 417B.

[0216] The pretilt angle directions 419A and 419B of the alignment layers have antiparallel components in the plane of the alignment layers 417A and 417B. The pretilt angle directions 419A and 419B refer to the orientation of the liquid crystal molecules 421 adjacent to the layers. Components 419Ay and 419By are in-plane components and are antiparallel to each other. Component 419Az at the perpendicular alignment layer 417A is much larger than component 419Ay, while component 419Bz at the plane alignment layer 417B is much smaller than component 419By. The pretilt angles are the angles between directions 419A and 419Ay, and between directions 419B and 419By.

[0217] Components 419Ay and 419By are oriented in a first direction parallel to the y-axis in the plane of the orientation layer.

[0218] In the current illustrative implementation and as Figure 6A As illustrated in the figure, at least one passive compensation retarder 330 of one of at least a first-pole controlled retarder 330A and at least one second-pole controlled retarder 330B is arranged on the same side of the switchable liquid crystal retarder 314 as the surface alignment layer 417A, which is arranged to provide vertical alignment in the adjacent liquid crystal material 421. At least one second-pole controlled retarder 330 includes a passive uniaxial retarder (i.e., a C-plate) having an optical axis perpendicular to the plane of the retarder 330.

[0219] In an alternative implementation, the passive retarder 330 may include an "intersecting" A-plate. In this disclosure, intersecting A-plates refer to a pair of passive uniaxial retarders having intersecting optical axes in the plane of the retarder, such as by means of... Figure 6C The delay units 330A and 330B in the diagram are illustrated.

[0220] Figure 6BThis is a schematic diagram illustrating the structure of a polarity control retarder in a side perspective view. The polarity control retarder includes a passive C-plate and an active liquid crystal layer comprising two planar alignment layers, wherein the pretilt angle direction of the alignment layers has an antiparallel component in the plane of the alignment layers.

[0221] Figure 6C This is a side perspective view illustrating the structure of the polarity control retarder and a schematic diagram of an active liquid crystal layer including two planar alignment layers, wherein the polarity control retarder includes intersecting A plates.

[0222] Figure 6D This is a schematic diagram illustrating the structure of a polarity control retarder in a side perspective view. The polarity control retarder includes a passive C-plate and an active liquid crystal layer comprising two vertical alignment layers, wherein the pretilt angle direction of the alignment layers has an antiparallel component in the plane of the alignment layers.

[0223] Figure 6E This is a side perspective view illustrating the structure of the polarization retarder and a schematic diagram of an active liquid crystal layer including two planar alignment layers, wherein the polarization retarder includes intersecting A-plates. Advantageously, compared to Figure 6D In the C-board 330 implementation scheme, higher delays for passive delayers 330A and 330B can be provided at a lower cost.

[0224] In the current implementation, one of the polar control delayers 300A and 300B may include Figure 6A The polar control delay 300, and another of the polar control delays 300A and 300B may include Figure 6B -E is one of the pole-controlled delayers 300. At least one passive compensation delayer of at least one first pole-controlled delayer and at least one second pole-controlled delayer may include: a passive single-axis delayer having an optical axis perpendicular to the plane of the delayer; or a pair of passive single-axis delayers having intersecting optical axes in the plane of the delayer.

[0225] With respect to the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers can be arranged to provide vertical alignment in adjacent liquid crystal materials. Advantageously, compared to an arrangement where two of the alignment layers have surface alignment, reduced voltage and power consumption can be provided in a common mode.

[0226] With respect to the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers can be arranged to provide planar alignment in adjacent liquid crystal materials. Advantageously, compared to an arrangement where the two alignment layers have a vertical alignment, the visibility of defects in relation to the applied voltage can be reduced.

[0227] Figure 6A Features of the implementation of -C that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations in the features.

[0228] refer to Figure 1A -B、 Figure 4A -B and Figure 5A Regarding the arrangement of -B, with respect to one of at least one first-pole controlled delay 300A and at least one second-pole controlled delay 300B, one of the surface alignment layers 417A or 417B is arranged to provide uniform alignment in adjacent liquid crystal material, and the other of the surface alignment layers 417B or 417A is arranged to provide vertical alignment in adjacent liquid crystal material 421. With respect to the other of at least one first-pole controlled delay 300A and at least one second-pole controlled delay 300B, the two surface alignment layers 417A, 417B are arranged to provide uniform alignment in adjacent liquid crystal material, or the two surface alignment layers 417A, 417B are arranged to provide vertical alignment in adjacent liquid crystal material.

[0229] The operation of the pole-controlled retarder between parallel polarizers is further described in U.S. Patent No. 10,126,575 and in U.S. Patent Publication No. 2019-0086706 (Atty.Ref. No. 412101), both of which are incorporated herein by reference in their entirety. The operation of a plurality of pole-controlled retarders of this embodiment in a common operating mode will now be described.

[0230] Figure 7A It is illustrated in the side view. Figure 1A This is a schematic diagram illustrating the operation of transmitted light from the spatial light modulator in a common operating mode. In the embodiment described below, light 400 perpendicular to the display (or in the frontal direction) is transmitted by display polarizer 219 in polarization state 360, which is not modified by polarization control delay units 300A, 300B and polarizers 318A, 302 and 318B. Such light is transmitted with high brightness.

[0231] In common mode, light rays 402 with a non-zero polar angle to the normal direction are also transmitted with the same polarization state 360, which is essentially unmodified by the polar control delay units 300A and 300B and polarizers 318A, 302, and 318B. The polar coordinate curve of the brightness from the spatial light modulator is likely to remain essentially unmodified. Advantageously, the display is visible from a wide range of polar coordinate viewing positions, and can be viewed by multiple display users.

[0232] Figure 7B It is illustrated in the side view. Figure 1A This is a schematic diagram illustrating the operation of the ambient light 604 in a common operating mode. Light rays 404 and 406 are incident on the display device 100 in a substantially unpolarized state 370. Polarizer 318B provides a polarization state 360, which is incident on the first-pole controlled delay unit and is substantially unmodified for the front light 404 and the off-axis light 406. Therefore, light that is substantially not reflected by the display is absorbed in the spatial light modulator 48 and the backlight 20 (if present). The display reflectivity remains low for a wide range of viewing directions, and advantageously, a high-contrast image is seen by multiple display users.

[0233] The operation of the extreme control delayer in privacy operation mode will now be described.

[0234] Figure 7C It is illustrated in the side view. Figure 1A This is a schematic diagram illustrating the operation of transmitted light from a spatial light modulator in a privacy operating mode with high reflectivity of ambient light. The frontal ray 400 has a polarization state 360, which is substantially unmodified by the polarization control retarders 300A and 300B. In comparison, the off-axis ray 402 has an output from the first polarization control retarder, the output having a given phase difference to provide a generally elliptical state 362A. Upon incident on the first additional polarizer 318A, the brightness of ray 402 is reduced in the output state 360. Ray 402 is transmitted with minimal loss through the reflective polarizer 302 and incident on the second polarization control retarder 300B, where further phase modulation is provided, and the output polarization state 362B is achieved. This state 362B is at least partially absorbed by the second additional polarizer 318B. Ray 402 is thus polarized at an off-axis polar location with... Figure 7A The light transmitted through 402 has reduced brightness compared to the light transmitted through 402.

[0235] Figure 7D It is illustrated in the side view. Figure 1AThis is a schematic diagram of the arrangement in privacy operation mode, using the high reflectivity of ambient light for operation. Frontally incident ambient light 404 is transmitted, accompanied by reflection from the reflective polarizer 302.

[0236] By comparison, light 406 undergoes phase modulation at the pole control retarder 300B, such that state 364 illuminates the reflective polarizer. The resolved polarization state 366, orthogonal to the electric vector transmission direction 303 of the reflective polarizer 302, is reflected and passes through the pole retarder, such that polarization state 368 is incident on the second additional polarizer. The component of state 368 parallel to the electric vector transmission direction of polarizer 318B is thus transmitted. For an off-axis observer, the display appears to have increased reflectivity. As described above, this increased reflectivity advantageously achieves an improved safety factor S.

[0237] Figure 7A Features of the implementation of -D that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0238] Figure 7A -D operations and Figure 1A -B and Figure 4A The layout is the same.

[0239] Figure 1A -B and Figure 4A The implementation scheme may further omit the reflective polarizer 302. In such a non-reflective structure and in Figure 5A middle, Figure 7A and 7C This applies only to operations where the reflective polarizer 302 is omitted; that is, in embodiments where the reflective polarizer 302 is omitted, reflectivity is not increased. Advantageously, the display can be provided with low reflectivity in privacy operating mode. For example, a display intended for use in bright ambient environments (such as daytime operation in a car) may not provide reflectivity enhancement in privacy mode.

[0240] What is likely to be desired is a switchable privacy display with narrow-angle privacy access and wide-angle public mode.

[0241] Figure 8A The illustration in the front perspective view is used for Figure 1A The schematic diagram of the arrangement of polarizers and pole control delays in the implementation scheme is shown, wherein the first pole control delay 300A includes a vertical alignment layer 419AA and a surface alignment layer 419AB and a C plate 330A; and the second pole control delay 300B includes two surface alignment layers 419BA and 419BB, and the passive control delay includes intersecting A plates 330BA and 330BB.

[0242] Figure 8A Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0243] In the current embodiment, the liquid crystal retarder 301 having two vertically aligned layers is preferably provided with a passive retarder 330, which includes a negative C-plate. In an alternative embodiment, such a retarder can also be provided with intersecting A-plates; however, such an embodiment is not described in further detail herein.

[0244] In the current embodiment, the liquid crystal retarder 301 having two planar alignment layers is preferably provided with a passive retarder 330, the passive retarder 330 comprising intersecting A plates or at least one negative C plate.

[0245] In the current embodiment, the liquid crystal retarder 301 having a planar alignment layer and a vertical alignment layer is preferably provided with a passive retarder 330, which includes at least one intersecting negative C-plate. Preferably, the negative C-plate is on the same side of the liquid crystal layer 314 as the vertical alignment layer, i.e., the vertical alignment layer 417A is between the liquid crystal layer 314 and the passive retarder 330. In an alternative embodiment, such a retarder may also be provided by intersecting A-plates; however, such an embodiment is not described in further detail herein.

[0246] Now refer to Figure 8B -J will discuss the illustrative implementation scheme of Table 1A.

[0247]

[0248] Table 1A

[0249] In the current embodiment, a switchable liquid crystal retarder 314, in which at least one of the first-pole controlled retarder and at least one of the second-pole controlled retarders is arranged to provide uniform alignment in adjacent liquid crystal materials (having a vertical alignment layer and a surface alignment layer), and the other of the surface alignment layers is arranged to provide vertical alignment in adjacent liquid crystal materials, is a first-pole controlled retarder 300A. The retarder has a liquid crystal retarder 314 that delays light with a wavelength of 550 nm, and the delay has a first delay value in the range of 700 nm to 2500 nm, preferably in the range of 850 nm to 1800 nm. The first of the at least one first-pole controlled retarder and at least one of the second-pole controlled retarders 300A further includes at least one passive compensation retarder.

[0250] As disclosed in Table 1A, the passive single-axis delayer 330A has a delay for light with a wavelength of 550 nm in the range of -400 nm to -2100 nm, preferably in the range of -700 nm to -1700 nm.

[0251] The switchable liquid crystal retarder 314A, which has a first pole control retarder (having a vertical alignment layer and a surface alignment layer), has a delay for light with a wavelength of 550 nm, and the delay has a first delay value. The other switchable liquid crystal retarder 300B, which has two surface alignment layers, has a delay for light with a wavelength of 550 nm, and the delay has a second delay value. The first delay value is greater than the second delay value.

[0252] The magnitude of the difference between half of the first delay value and the second delay value is at most 400 nm, and preferably at most 200 nm.

[0253] Figure 8B This is a graph illustrating the analog polar coordinate curves of the brightness output of the transmitting spatial light modulator. For example... Figure 1A As illustrated in the figure, the spatial light modulator 48 includes an emitting spatial light modulator arranged to output light, an output display polarizer 218 arranged on the output side of the emitting spatial light modulator 48, a second additional polarizer 318B arranged on the output side of the spatial light modulator 48 outside the first additional polarizer 318A, and at least one second pole control delay unit 300B arranged between the first additional polarizer 318A and the second additional polarizer 318B. Figure 8B The illustration shows that the spatial light modulator 48 has an output brightness curve, which has a full width at half maximum (FWHM) of at least 40 degrees, preferably at least 50 degrees.

[0254] In alternative arrangements (such as) Figure 3 As illustrated in the figure, the display device may further include a backlight 20 arranged to output light, and a spatial light modulator 48 including a transmissive spatial light modulator arranged to receive the output light from the backlight 20. The backlight may have an output brightness profile having a full width at half maximum (FWHM) of at least 40 degrees, preferably at least 50 degrees.

[0255] Figure 8C The diagram illustrates the arrangement between the first and second additional polarizers. Figure 8A The graph shows the simulated polar coordinate curves of the transmission of the second pole controlled delayer in Table 1A, where the electric vector transmission direction of the polarizer is parallel. Figure 8D The diagram illustrates the arrangement between the reflective polarizer and the second additional polarizer. Figure 8AThe simulated polar coordinate curve of the reflectivity of the second-pole controlled retarder is plotted, where the electric vector transmission direction of the polarizer is parallel; and Figure 8E This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 8D The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device.

[0256] Figure 8F The illustration shows the arrangement between the display polarizer and the first additional polarizer. Figure 8A The graph shows the simulated polar coordinate curves of the transmission of the first-pole controlled retarder in Table 1A, where the electric vector transmission direction of the polarizer is parallel. The pretilt direction of the first-pole controlled retarder 300A is parallel to or antiparallel to the pretilt direction of the second-pole controlled retarder 300B.

[0257] Figure 8G This is a diagram illustrating the meaning of... Figure 8B polar curve of -F Figure 8A The graph shows the analog polar coordinate curves of the logarithm of the total output brightness of the spatial light modulator, the first pole control delay, and the second pole control delay in Table 1A.

[0258] As mentioned above, the security performance of a display can be determined using the visual security level S as the polar coordinates change with the extreme viewing angle.

[0259] Figure 8H This illustration shows the ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits. Figure 8A A graph of the simulated polar coordinate curves of the safety level S of the arrangement in Table 1; and Figure 8I The illustration shows the ambient illuminance, measured in lux, which is twice the brightness of the front display as measured in nits. Figure 8A The graph shows the simulated lateral curves of the visual safety factor at zero elevation angle for the arrangement in Table 1A. Therefore, using... Figure 1A Typical brightness curve of a emitting display Figure 8A The arrangement in Table 1A allows for a privacy access angle of approximately 37 degrees 140°. Advantageously, an observer at a 45-degree polar angle with zero elevation may see virtually no image information, regardless of the image content under such ambient lighting conditions. Furthermore, the display achieves an enhanced level of security in the upper quadrant (an azimuth angle of approximately + / - 45 degrees north). In operation, the privacy display desirously provides a higher level of security against eavesdroppers in the top-view quadrant. In this top-view quadrant, a high security factor is desirously achieved.

[0260] Figure 8JThis illustration shows the ambient illuminance, measured in lux, as twice the brightness of a front-facing display, measured in nits and operating in common mode. Figure 8A The arrangement of the security level S is plotted as a simulated polar coordinate curve. Advantageously, the image visibility (S<0.1) is maintained at the widest viewing angle, so that the display can be easily seen with high contrast from extreme viewing angles greater than 45 degrees.

[0261] Other illustrative embodiments are illustrated in Tables 1B-F, and Table 2 compares the privacy turn-on angle 140° for each illustrative embodiment. The embodiment including a C-plate compared to the intersecting A-plate can advantageously be thinner and cheaper than the arrangement in Table 1A. The embodiment including two vertically oriented layers compared to two surface-oriented layers can advantageously achieve common-mode operation with zero voltage and can have lower power consumption. The embodiment in which the first delayer 300A includes a vertically oriented layer and a surface-oriented layer advantageously achieves a smaller privacy turn-on angle 140° while maintaining a high level of security at higher polar angles.

[0262]

[0263] Table 1B

[0264] With respect to the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers are arranged to provide surface alignment in adjacent liquid crystal materials.

[0265] By comparing with the illustrative embodiments in Table 1A, Table 1B provides that one of the switchable liquid crystal retarder 314B (having a vertical alignment layer and a surface alignment layer) with a second pole control retarder has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the other of the switchable liquid crystal retarder 300B (having two surface alignment layers) with a first pole control retarder has a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value.

[0266] Regarding the other of at least one first-pole controlled delay device and at least one second-pole controlled delay device (having the same type of alignment layer) for the second-pole controlled delay device 300A in Table 1A and the first-pole controlled delay device in Table 1B, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 450 nm to 900 nm, preferably in the range of 550 nm to 800 nm, and the other of at least one first-pole controlled delay device and at least one second-pole controlled delay device further includes a pair of passive single-axis delay devices, the passive single-axis delay devices having intersecting optical axes in the plane of the delay device and each having a delay of light with a wavelength of 550 nm in the range of 250 nm to 800 nm, preferably in the range of 400 nm to 625 nm.

[0267]

[0268] Table 1C

[0269]

[0270] Table 1D

[0271] With respect to the illustrative embodiments of Tables 1C-D, regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay in the range of 500 nm to 900 nm (preferably 600 nm to 850 nm) for light with a wavelength of 550 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay in the range of -300 nm to -700 nm, preferably in the range of -350 nm to -600 nm, for light with a wavelength of 550 nm.

[0272]

[0273] Table 1E

[0274]

[0275] Table 1F

[0276] With respect to the illustrative embodiments in Tables 1E-F, regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay of light with a wavelength of 550 nm in the range of -300 nm to -900 nm, preferably in the range of -400 nm to -800 nm.

[0277]

[0278] Table 2

[0279] Table 2 illustrates that Privacy Connectivity 140 can be implemented for angles less than 40 degrees. Advantageously, a spy at a 45-degree polar angle can have low image visibility at least at some azimuth angles.

[0280] exist Figure 4A and Figure 5A In an alternative embodiment of this disclosure illustrated in the figures, the display device may further include a backlight 20 arranged to output light, a spatial light modulator 48 including a transmissive spatial light modulator 48 arranged to receive the output light from the backlight 20, and the other of at least one first-pole control delay unit and at least one second-pole control delay unit (having an alignment layer of the same type) located between the backlight 20 and the transmissive spatial light modulator 48. Advantageously, the visibility of flow due to the high recovery time of the vertical alignment layer can be reduced.

[0281] What might be desired is a display with a small 140-degree on / off angle, while maintaining a high level of safety for off-axis viewing. References will now be made. Figure 9A -H Discuss the illustrative implementation plan in Table 3A.

[0282] In the embodiments of Tables 3A-D, a switchable liquid crystal retarder (having a vertical alignment layer and a horizontal alignment layer) of at least one first-pole controlled retarder and at least one second-pole controlled retarder has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and a switchable liquid crystal retarder (having the same type of alignment layer) of at least one first-pole controlled retarder and at least one second-pole controlled retarder has a delay for light with a wavelength of 550 nm, the delay having a second delay value, half of the first delay value being less than the second delay value.

[0283]

[0284] Table 3A

[0285] Figure 9A This is a graph illustrating the analog polar coordinate curve of the brightness output of the transmissive spatial light modulator 48 illuminated by the collimated backlight 20. The display device 100 therefore further includes a backlight 20 arranged to output light, and the spatial light modulator 48 includes a transmissive spatial light modulator arranged to receive the output light from the backlight. The backlight has an output brightness curve having a full width at half maximum (FWHM) of up to 40 degrees. As described below... Figure 12A As described in -B, the spatial light modulator may alternatively include an emitting spatial light modulator and a parallax barrier 700.

[0286] The discussion will now cover the layers and collimated backlight 20, including those in Table 3A. Figure 8A Optical stacking.

[0287] Figure 9B This is a graph of the simulated polar coordinate curve of the transmission of the second-stage control delayer in Table 3A. Figure 9C This is a graph of the simulated polar coordinate curve of the reflectivity of the second-pole control delay unit in Table 3A. Figure 9D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 9C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device.

[0288] Figure 9E This is a graph of the simulated polar coordinate curve of the transmission of the first-stage control delayer in Table 3A. The pretilt angle direction of the first-stage control delayer 300A is parallel to or antiparallel to the pretilt angle direction of the second-stage control delayer 300B.

[0289] Figure 9F This is a diagram illustrating the meaning of... Figure 9A A graph of the analog polar coordinates of the logarithmic output brightness of the spatial light modulator and the first and second pole control delay units, representing the polar coordinate curve of -E.

[0290] Figure 9G This is a diagram illustrating the meaning of... Figure 9A The polar curve of -E represents the ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits. Figure 8A The layout and Figure 9A The curve of -F represents the safety level S, and is a graph of the simulated polar coordinate curve. Figure 9H This is a diagram illustrating the meaning of... Figure 9A-E is a graph of the polar coordinate curve of the simulated lateral curve of the visual safety factor of the arrangement at a zero elevation angle, which is twice the ambient illuminance measured in lux and is the frontal display brightness measured in nits.

[0291] Other illustrative implementations are illustrated in Tables 3B-D, and Table 4 compares the privacy access angle 140 for each illustrative implementation. Implementations can target... Figure 1A -B arrangement or alternatives for Figure 4A The arrangement of -B is provided, wherein the arrangement includes a reflective polarizer 302.

[0292] Compared to the arrangement in Table 3A, the implementation including a C-plate compared to the intersecting A-plate can advantageously be thinner and cheaper. The implementation including two vertically oriented layers compared to two surface-oriented layers can advantageously achieve common-mode operation with zero voltage and can have lower power consumption. The implementation of the first delayer 300A including one vertically oriented layer and one surface-oriented layer advantageously achieves a smaller privacy turn-on angle 140° while maintaining a high level of security at higher polar angles.

[0293]

[0294] Table 3B

[0295]

[0296] Table 3C

[0297]

[0298] Table 3D

[0299] With respect to the illustrative embodiments in Tables 3A-D, the retarder (having a vertical alignment layer and a horizontal alignment layer) has a liquid crystal retarder 314, which has a delay for light with a wavelength of 550 nm, and the delay has a first delay value in the range of 700 nm to 2500 nm, preferably in the range of 850 nm to 1800 nm.

[0300] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, wherein the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 700 nm to 2500 nm, preferably in the range of 850 nm to 1800 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further comprises a pair of passive single-axis retarders having intersecting optical axes in the plane of the retarder, and each having a delay of light with a wavelength of 550 nm in the range of 600 nm to 1600 nm, preferably in the range of 750 nm to 1300 nm.

[0301] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder, wherein two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 700 nm to 2500 nm, preferably in the range of 1000 nm to 1800 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay of light with a wavelength of 550 nm in the range of -700 nm to -2500 nm, preferably in the range of -900 nm to -1800 nm.

[0302]

[0303] Table 4

[0304] Figure 9I This illustration shows the ambient illuminance, measured in lux, as twice the brightness of a front-facing display, measured in nits and operating in common mode. Figure 9A The safety level S of the arrangement is represented by a simulated polar coordinate curve. (Compared to the use of...) Figure 8B Compared to a wide-angle launch configuration, it has Figure 9A The collimated backlight of the brightness curve achieves improved privacy viewing angles, but with a narrow polar angle range, within which other observers can see a high-contrast image (S<0.1) in privacy mode. Such a display is ideal for display applications primarily used by a single viewer as well as occasional use by multiple users.

[0305] What might be desired is a switchable privacy display without the reflective polarizer 302. Reference will now be made to... Figure 10A -H discusses the illustrative implementation of Table 3A. Furthermore, the arrangements of Tables 3B-D can be provided in such an implementation.

[0306] Figure 10A This is a graph illustrating the analog polar coordinate curve of the brightness output of a transmissive spatial light modulator illuminated by a collimated backlight; the display may include... Figure 5A -B arrangement. Alternatively, Figure 1A The -B arrangement is not provided with a reflective polarizer 302 and is provided with Figure 3 Spatial light modulator. Alternatively, Figure 4A The -B arrangement may not be provided with a reflective polarizer 302.

[0307] Figure 10B This is a graph illustrating the simulated polar coordinate curves of the transmission of the second-stage control delayer. Figure 10C This is a graph illustrating the simulated polar coordinate curves of the reflectivity of a second-pole controlled retarder without a reflective polarizer.

[0308] Figure 10D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 9C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device without a reflective polarizer.

[0309] Figure 10E This is a graph illustrating the simulated polar coordinate curves of the transmission of the first-stage control delayer 300A. The pretilt angle direction of the first-stage control delayer 300A is parallel or antiparallel to the pretilt angle direction of the second-stage control delayer 300B.

[0310] Figure 10F The illustration is for Figure 10A A graph of the analog polar coordinates of the logarithmic output brightness of the spatial light modulator and the first and second pole control delay units, representing the polar coordinate curve of -E.

[0311] Figure 10G This is a graph illustrating the simulated polar coordinate curve of the safety level S for an arrangement without a reflective polarizer, where the ambient illuminance is measured in lux and is twice the brightness of the front display (measured in nits). Figure 10H This is a graph illustrating the simulated lateral curve of the visual safety factor at a zero-degree elevation angle for an arrangement with ambient illuminance measured in lux, which is twice the brightness of the frontal display measured in nits.

[0312] The relative performance at a switching angle of 140° is illustrated in Table 5. The order of the first-pole control delay unit 300A and the second-pole control delay unit 300B does not change the output polar coordinate curve.

[0313]

[0314] Table 5

[0315] Advantageously, compared to an arrangement with reflective polarizer 302, the display can be provided with a lower reflectivity. Such an arrangement may be desirable in certain operating environments (such as a car cabin under bright sunlight).

[0316] The desired outcome is a privacy display that provides off-axis viewing in both landscape and portrait modes, achieving a high level of security. References will now be made. Figure 11A -G Discuss the illustrative implementation plan in Table 6A.

[0317]

[0318] Table 6A

[0319] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 450 nm to 900 nm, preferably in the range of 550 nm to 800 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a pair of passive single-axis retarders having intersecting optical axes in the plane of the retarder, and each having a delay of light with a wavelength of 550 nm in the range of 250 nm to 800 nm, preferably in the range of 400 nm to 625 nm.

[0320] Figure 11A This is a graph illustrating the simulated polar coordinate curve of the brightness output of a transmissive spatial light modulator illuminated by a collimated backlight source. Figure 11B This is a graph illustrating the simulated polar coordinate curves of the transmission of the second-stage control delayer. Figure 11C This is a graph illustrating the simulated polar coordinate curve of the reflectivity of the second-stage control delay; and Figure 11D This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes... Figure 11C The reflectivity of the display and the Fresnel reflectivity from the front surface of the display device.

[0321] The surface alignment layer of the other of at least one first-pole controlled delay device and at least one second-pole controlled delay device (having the same type of alignment layer) has a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a second pair of antiparallel directions.

[0322] Figure 11EThis is a graph illustrating the simulated polar coordinate curves of the transmission of the first-stage controlled retarder, where the pretilt angle direction of the first-stage controlled retarder is orthogonal to the pretilt angle direction of the second-stage controlled retarder. The pretilt angle direction of the first-stage controlled retarder 300A is orthogonal to the pretilt angle direction of the second-stage controlled retarder 300B. The surface alignment layer of at least one of the first-stage and at least one second-stage controlled retarder (having a vertical alignment layer and a surface alignment layer) has a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a first pair of antiparallel directions.

[0323] exist Figure 11A -G and Figure 12A In the illustrative embodiment of -J, the first pair of antiparallel directions intersects with the second pair of antiparallel directions. Viewed from a plane perpendicular to the liquid crystal material layer of at least one first-electrode control retarder and at least one second-electrode control retarder, the first pair of antiparallel directions forms a 90-degree angle with the second pair of antiparallel directions.

[0324] A switchable liquid crystal retarder having at least one of a first-pole controlled retarder and at least one of a second-pole controlled retarder (having a vertical alignment layer and a horizontal alignment layer) has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and a switchable liquid crystal retarder having at least one of a first-pole controlled retarder and at least one of a second-pole controlled retarder (having an alignment layer of the same type) has a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value.

[0325] The magnitude of the difference between half of the first delay value and the second delay value is at most 400 nm, and preferably at most 200 nm.

[0326] Figure 11F This is a graph illustrating the logarithmic output brightness of the spatial light modulator, the first-pole control delay unit, and the second-pole control delay unit in analog polar coordinates.

[0327] Figure 11G This is a diagram illustrating the meaning of... Figure 11A -F is a graph of the simulated polar coordinate curve of the safety level S for an arrangement without a reflective polarizer, which is twice the ambient illuminance measured in lux and is the front display brightness measured in nits.

[0328] Advantageously, a monitor with high visual security for both landscape and portrait operation in privacy mode, and a high security factor for off-axis viewing locations, can be provided. Such a monitor can be positioned similarly to... Figure 9I The security level illustrated in the diagram has been switched to public operating mode.

[0329] Tables 6B-C illustrate other illustrative implementation schemes. Implementation schemes may be targeted at… Figure 1A -B arrangement or alternatives for Figure 4A The -B arrangement is provided, wherein the arrangement includes a reflective polarizer 302. In other embodiments, the reflective polarizer 302 may be omitted.

[0330] Compared to the arrangement in Table 6A, the implementation including a C-plate compared to the intersecting A-plate can advantageously be thinner and cheaper. The implementation including two vertically oriented layers compared to two surface-oriented layers can advantageously achieve common-mode operation with zero voltage and can have lower power consumption. The implementation of the first delayer 300A including one vertically oriented layer and one surface-oriented layer advantageously achieves a smaller privacy turn-on angle 140° while maintaining a high level of security at higher polar angles.

[0331]

[0332] Table 6B

[0333] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of 550 nm wavelength light in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay of 550 nm wavelength light in the range of -300 nm to -700 nm, preferably in the range of -350 nm to -600 nm.

[0334]

[0335] Table 6C

[0336] Regarding the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder (having the same type of alignment layer), the two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a delay of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, preferably in the range of 600 nm to 850 nm, and the other of at least one first-pole controlled retarder and at least one second-pole controlled retarder further includes a passive single-axis retarder having an optical axis perpendicular to the plane of the retarder, and having a delay of light with a wavelength of 550 nm in the range of -300 nm to -800 nm, preferably in the range of -400 nm to -800 nm.

[0337] Table 7 compares... Figure 6A - Delay in the implementation of C.

[0338]

[0339] Table 7

[0340] The desired outcome is to provide off-axis viewing in both landscape and portrait modes of the transmitting display, achieving a high level of security for the privacy display. Now, let's refer to... Figure 12A -G, targeting Figure 2 The illustrative pixel plane 214 and parallax barrier 700 arrangement are used to discuss the illustrative implementation scheme of Table 9A.

[0341] Figure 12A This is a graph illustrating the simulated polar coordinate curve of the brightness output of the transmitting spatial light modulator.

[0342] like Figure 1A As illustrated in the figure, the spatial light modulator 48 includes an emitting spatial light modulator arranged to output light, and the display polarizer is an output display polarizer 218 arranged on the output side of the emitting spatial light modulator 48. The emitting spatial light modulator includes an array of pixels 220, 222, 224 arranged in the pixel layer 214, and the display device further includes a parallax barrier 700 forming an array of apertures 702, wherein the parallax barrier 700 is spaced from the pixel layer 214 by a parallax distance d along an axis normal to the plane of the pixel layer 214, and each pixel 220, 222, 224 is aligned with the aperture 702.

[0343] Figure 12B This diagram illustrates the light emitted from the pixels of the spatial light modulator. Figure 2A graph of the simulated polar coordinate curves of the transmission of the barrier structure. An illustrative example is provided in Table 8, wherein the emitting spatial light modulator 48 and the aligned parallax barrier 700 have output brightness curves with a full width at half maximum of 40 degrees.

[0344] Parameters, x-axis direction Explanatory value 224 pixel pitch 20 micrometers 224 pixels emission width 10 micrometers Barrier orifice width 702 10 micrometers Barrier interval d 20 micrometers

[0345] Table 8

[0346]

[0347] Table 9A

[0348] Figure 12C This is a graph illustrating the simulated polar coordinates of the transmission of a second-pole controlled delay unit arranged between a first and a second additional polarizer, where the electric vector transmission directions of the polarizers are parallel. Figure 12D This is a simulated polar coordinate graph illustrating the reflectivity of a second-pole controlled retarder arranged between a reflecting polarizer and a second additional polarizer, where the electric vector transmission directions of the polarizers are parallel; and Figure 12E This is a graph illustrating the simulated polar coordinate curve of total reflectance, which includes reflectance and Fresnel reflectance from the front surface of the display device.

[0349] Figure 12F This is a graph illustrating the simulated polar coordinate curve of the transmission of a first pole control delay unit arranged between a display polarizer and a first additional polarizer, wherein the electric vector transmission directions of the polarizers are parallel, and the pretilt direction of the first pole control delay unit 300A is orthogonal to the pretilt direction of the second pole control delay unit 300B.

[0350] Figure 12G This is a diagram. Figure 12A -F shows a simulated polar coordinate graph of the logarithmic output brightness of the spatial light modulator, the first-pole controlled delay unit, and the second-pole controlled delay unit; and Figure 12H This illustration shows the ambient illuminance measured in lux, which is twice the brightness of a front-facing display measured in nits. Figure 12A The layout of the polar coordinate curve of -G is a graph of the simulated polar coordinate curve of the safety level S.

[0351] Advantageously, a display that provides the desired security factor S in both landscape and portrait operation can be provided. Compared to the embodiment in Table 6A, the desired delay of the first pole control delay is shortened. Such a pole control delay provides high-angle brightness reduction, while the parallax barrier 700 provides lower-angle brightness reduction. Advantageously, the consistency of the improved security level is achieved in the transmitting display.

[0352] Figure 12I This is a graph illustrating the simulated polar coordinate curve of safety level S, where the first-level control delay is... Figure 12H The second-pole control delay, and the second-pole control delay is Figure 12H The first-stage control delay unit is illustrated in Table 9B. (And...) Figure 9A Compared to the previous arrangement, the privacy access angle is advantageously reduced in the lateral direction.

[0353]

[0354] Table 9B

[0355] In other embodiments, the first-pole control delay may include a vertically oriented layer to advantageously achieve reduced power consumption. In other embodiments, as described elsewhere herein, the first-pole control delay may include a passive C-plate delay to advantageously achieve reduced cost and complexity.

[0356] Figure 12J The illustration is for Figure 12A The -H arrangement is represented by a graph of the simulated polar coordinate curve of the safety level S for an arrangement with ambient illuminance measured in lux, which is twice the brightness of the front display measured in nits and operating in public mode. Advantageously, image visibility (S < 0.1) is maintained so that the display can be easily seen with high contrast from extreme viewing angles greater than 30 degrees in both landscape and portrait orientations.

[0357] Figure 13 This is a side perspective view illustrating a switchable privacy display assembly 102 for use with a spatial light modulator 48, which includes a first pole control delay 300A and a first additional polarizer 318A, a reflective polarizer 302, and a second pole control delay 300B disposed between the first additional polarizer 318A and the second additional polarizer 318B. Advantageously, the spatial light modulator 48 can be reconfigured in the factory or in the field for use as a switchable privacy display. Figure 13 Features of the implementation scheme that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0358] Various alternatives to the optical stacking of the current implementation will now be described.

[0359] Figure 14 It is about Figure 15A -F、 Figure 16A -F、 Figure 17A -C and Figure 18A Illustration of alternative stacking arrangements for -F.

[0360] Figure 15A -F is a side view illustrating an alternative stack of optical components for a switchable privacy display 100, wherein a first pole control delay unit 300A and a second pole control delay unit 300B are arranged to receive light from a transmission spatial light modulator 48 and a backlight 20. Figure 15A Features of the implementation of -F that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0361] Figure 16A -F is a side view illustrating an alternative stack of optical components for a switchable privacy display 100, wherein one of the first pole control delay unit 300A and the second pole control delay unit 300B is arranged to receive light from a transmission spatial light modulator 48, and the spatial light modulator 48 is arranged to receive light from the other of the first pole control delay unit 300A and the second pole control delay unit 300B and the backlight 20; and Figure 17A -C is a side view illustration of an alternative stack of optical components for a switchable privacy display, wherein a spatial light modulator 48 is arranged to receive light from a first pole control delay unit 300A, a second pole control delay unit 300B, and a backlight 20. Figure 16A -F and Figure 17A Features of the implementation of -C that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations in the features.

[0362] Figure 18A -F is a side view illustrating an alternative to the optical component stack for the switchable privacy display 100, wherein a first pole control delay unit 300A and a second pole control delay unit 300B are arranged to receive light from the emission spatial light modulator 48. Figure 18A Features of the implementation of -F that are not discussed in further detail may be assumed to correspond to features with equivalent labels as discussed above, including any possible variations of the features.

[0363] exist Figure 15A -F、 Figure 16A -F、 Figure 17A -C and Figure 18A In the substitutions for -F, various substitutions are illustrated and can be described more generally as follows.

[0364] For each pole-controlled delay 300A, 300B including liquid crystal delay 314A, 314B having two planar alignment layers 417A, 417B, the respective passive delay 330A, 330B or a pair of intersecting passive delay 330AA, 330AB or 330BA, 330BB can be arranged to either receive light from the respective liquid crystal delay 314A, 314B; or the liquid crystal delay 314A, 314B can be arranged to receive light from the respective passive delay 330A, 330B or a pair of intersecting passive delay 330AA, 330AB or 330BA, 330BB.

[0365] For each pole-controlled retarder 300A, 300B comprising a surface-aligned layer 417A and a vertical-aligned layer 417B of liquid crystal retarder 314A, 314B, the vertical-aligned layer is preferably arranged between the respective liquid crystal material layers 421A, 421B and the respective passive retarder 330A, 330B. Advantageously, the size of the pole region for reduced brightness in privacy mode is increased.

[0366] for Figure 15A , 15C 15E Figure 16A , 16C 16E and Figure 18A , 18C As an alternative to 18E, one of the polarization control delay units 300A and 300B can be arranged between the reflective polarizer 302 and the further additional polarizer 318B. Advantageously, the reflectivity of the display 100 in privacy operation mode can be increased, and the security factor is improved.

[0367] Figure 15A -F、 Figure 16A -F and Figure 17A -C, in which the transmission spatial light modulator 48 and backlight 20 are omitted, or... Figure 18A The omitted space light modulator 48 in -F can be replaced by, for example, Figure 13 The alternative components illustrated in the figure.

[0368] As may be used herein, the terms “substantially” and “approximately” provide industry-accepted tolerances for their corresponding terms and / or the correlation between terms. Such industry-accepted tolerances are in the range of 0% to 10% and correspond to (but are not limited to) component values, angles, etc. Such correlation between terms is in the range of approximately 0% to 10%.

[0369] While various embodiments based on the principles disclosed herein have been described above, it should be understood that they are presented merely as examples and not as limitations. Therefore, the breadth and scope of this disclosure should not be limited to any of the exemplary embodiments described above, but should be defined solely by any claims published from this disclosure and their equivalents. Furthermore, while the foregoing advantages and features are provided in the described embodiments, the application of such published claims should not be limited to processes and structures for achieving any or all of the foregoing advantages.

[0370] Furthermore, the paragraph headings herein are provided for consistency with the recommendations under 37 CFR 1.77 or to provide organizational clues. These headings should not limit or characterize one or more embodiments that can be set forth from any of the claims published in this disclosure. Specifically, and by way of example, although the heading refers to “Technical Field,” the claims should not be limited by the language chosen under that heading to describe the so-called technical field. Furthermore, the description of the technology in the “Background Art” section is not to be interpreted as an admission that a particular technology is prior art to any one or more embodiments of this disclosure. “Summary of the Invention” is also not to be considered as a characteristic description of one or more embodiments set forth in the published claims. Additionally, any reference to the singular “invention” in this disclosure should not be used to prove that there is only one novel point in this disclosure. Multiple embodiments may be set forth according to the definition of the multiple claims published from this disclosure, and these claims accordingly define one or more embodiments protected by them, as well as their equivalents. In all cases, the scope of these claims should be understood according to the substance of the claims themselves, and not limited by the headings listed herein.

Claims

1. A display device, the display device comprising: Spatial light modulator; A display polarizer is arranged on one side of the spatial light modulator, and the display polarizer is a linear polarizer; A first additional polarizer is arranged on the same side of the spatial light modulator as the display polarizer, and the first additional polarizer is a linear polarizer. At least one first pole control delay unit is disposed between the first additional polarizer and the display polarizer; The second additional polarizer is a linear polarizer; as well as At least one second-pole controlled delay unit, wherein the second additional polarizer is disposed on the same side of the spatial light modulator as the first additional polarizer, outside the first additional polarizer, and the at least one second-pole controlled delay unit is disposed between the first additional polarizer and the second additional polarizer; and the display device further includes a backlight arranged for output light, the spatial light modulator includes a transmission spatial light modulator arranged for receiving output light from the backlight, the display polarizer is an input display polarizer disposed on the input side of the spatial light modulator, and the display device further includes an output display polarizer disposed on the output side of the spatial light modulator, the second additional polarizer is disposed on the output side of the spatial light modulator, and the at least one second-pole controlled delay unit is disposed between the second additional polarizer and the output display polarizer. in: Each of the at least one first-pole controlled delay unit and the at least one second-pole controlled delay unit includes a respective switchable liquid crystal delay unit, the switchable liquid crystal delay unit comprising a liquid crystal material layer and two surface alignment layers, the two surface alignment layers being configured to be adjacent to the liquid crystal material layer and on opposite sides of the liquid crystal material layer. Regarding one of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, one of the surface alignment layers is arranged to provide uniform alignment in adjacent liquid crystal material, and the other of the surface alignment layers is arranged to provide vertical alignment in adjacent liquid crystal material. With respect to the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, both surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, or both surface alignment layers are arranged to provide vertical alignment in adjacent liquid crystal materials.

2. The display device according to claim 1, wherein the switchable liquid crystal delay of one of the at least one first pole control delay and the at least one second pole control delay has a delay for light with a wavelength of 550 nm, the delay having a first delay value in the range of 700 nm to 2500 nm.

3. The display device according to any one of the preceding claims, wherein the at least one first-pole control delay unit and the at least one second-pole control delay unit further comprises at least one passive compensation delay unit.

4. The display device of claim 3, wherein the at least one passive compensation delay of one of the at least one first pole control delay and the at least one second pole control delay is arranged on the same side of the switchable liquid crystal delay as the surface alignment layer arranged to provide vertical orientation in adjacent liquid crystal material.

5. The display device according to claim 3, wherein the at least one of the at least first pole control delay and the at least one second pole control delay comprises a passive compensation delay, the passive single-axis delay having an optical axis perpendicular to the plane of the passive single-axis delay.

6. The display device according to claim 5, wherein the passive single-axis delayer has a delay in the range of -400nm to -2100nm for light with a wavelength of 550nm.

7. The display device according to claim 1, wherein The display device further includes a reflective polarizer, which is a linear polarizer, and The display polarizer is an output display polarizer arranged on the output side of the spatial light modulator. The second additional polarizer is arranged on the same side of the spatial light modulator as the first additional polarizer, outside the first additional polarizer. The at least one second-pole control delay unit is arranged between the first additional polarizer and the second additional polarizer, and the reflection polarizer is arranged between the first additional polarizer and the at least one second-pole control delay unit. The display device further includes a backlight arranged to output light, the spatial light modulator includes a transmissive spatial light modulator arranged to receive the output light from the backlight, the display polarizer is an input display polarizer arranged on the input side of the spatial light modulator, and the display device further includes an output display polarizer arranged on the output side of the spatial light modulator, a second additional polarizer arranged on the output side of the spatial light modulator, the at least one second pole control delay unit arranged between the second additional polarizer and the output display polarizer, and the reflective polarizer arranged between the output display polarizer and the at least one second pole control delay unit.

8. The display device according to claim 7, wherein one of the at least first pole control delay device and the at least second pole control delay device is the at least second pole control delay device, and the other of the at least first pole control delay device and the at least second pole control delay device is the at least first pole control delay device.

9. The display device of claim 1, wherein the switchable liquid crystal delay of one of the at least one first-pole control delay device and the at least one second-pole control delay device has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the switchable liquid crystal delay of the other of the at least one first-pole control delay device and the at least one second-pole control delay device has a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value.

10. The display device of claim 9, wherein the magnitude of the difference between half of the first delay value and the second delay value is at most 400 nm.

11. The display device according to claim 9, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, which have a retarding of light with a wavelength of 550 nm in the range of 450 nm to 900 nm. The other of the at least one first-pole controlled delayer and the at least one second-pole controlled delayer further includes a pair of passive single-axis delayers having intersecting optical axes in the plane of the delayers, and each having a delay in the range of 250 nm to 800 nm for light with a wavelength of 550 nm.

12. The display device according to claim 9, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, and The other of the at least one first-pole controlled delay unit and the at least one second-pole controlled delay unit further includes a passive single-axis delay unit having an optical axis perpendicular to the plane of the delay unit and having a delay in the range of -300nm to -700nm for light with a wavelength of 550nm.

13. The display device according to claim 9, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, and The other of the at least one first-pole controlled delay and the at least one second-pole controlled delay further includes a passive single-axis delay having an optical axis perpendicular to the plane of the delay and having a delay in the range of -300nm to -900nm for light with a wavelength of 550nm.

14. The display device of claim 9, wherein the spatial light modulator includes an emitting spatial light modulator arranged to output light, the display polarizer is an output display polarizer arranged on the output side of the emitting spatial light modulator, the second additional polarizer is arranged on the output side of the spatial light modulator, outside the first additional polarizer, and the at least one second pole control delay unit is arranged between the first additional polarizer and the second additional polarizer.

15. The display device of claim 14, wherein the emitted spatial light modulator has an output brightness curve having a full width at half maximum (FWHM) of at least 40 degrees.

16. The display device of claim 9, wherein the display device further comprises a backlight source arranged to output light, and the spatial light modulator comprises a transmissive spatial light modulator arranged to receive the output light from the backlight source.

17. The display device of claim 16, wherein the backlight has an output brightness curve having a full width at half maximum (FWHM) of at least 40 degrees.

18. The display device of claim 1, wherein the switchable liquid crystal delay of one of the at least one first-pole control delayer and the at least one second-pole control delayer has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the switchable liquid crystal delay of the other of the at least one first-pole control delayer and the at least one second-pole control delayer has a delay for light with a wavelength of 550 nm, the delay having a second delay value, half of the first delay value being less than the second delay value.

19. The display device according to claim 18, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 700 nm to 2500 nm, and The other of the at least one first-pole controlled delayer and the at least one second-pole controlled delayer further includes a pair of passive single-axis delayers having intersecting optical axes in the plane of the delayers, and each having a delay in the range of 600 nm to 1600 nm for light with a wavelength of 550 nm.

20. The display device according to claim 18, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 700 nm to 2500 nm, and The other of the at least one first-pole controlled delay and the at least one second-pole controlled delay further includes a passive single-axis delay having an optical axis perpendicular to the plane of the delay and having a delay in the range of -700nm to -2500nm for light with a wavelength of 550nm.

21. The display device of claim 18, wherein the spatial light modulator includes an emitting spatial light modulator arranged to output light, the display polarizer is an output display polarizer arranged on the output side of the emitting spatial light modulator, the second additional polarizer is arranged on the output side of the spatial light modulator, outside the first additional polarizer, and the at least one second pole control delay is arranged between the first additional polarizer and the second additional polarizer.

22. The display device according to claim 21, wherein The emitted spatial light modulator includes a pixel array arranged in a pixel layer, and The display device further includes a parallax barrier forming an array of apertures, wherein the parallax barrier is spaced apart from the pixel layer by a parallax distance along an axis of the normal to the plane of the pixel layer, and each pixel is aligned with an aperture.

23. The display device of claim 22, wherein the emitting spatial light modulator and the parallax barrier have an output brightness curve having a full width at half maximum (FWHM) of up to 40 degrees.

24. The display device of claim 18, wherein the display device includes a backlight source arranged to output light, and the spatial light modulator includes a transmissive spatial light modulator arranged to receive the output light from the backlight source.

25. The display device according to claim 24, wherein the backlight has an output brightness curve having a full width at half maximum (WHM) of up to 40 degrees.

26. The display device according to claim 1, wherein The surface alignment layer of one of the at least one first-pole controlled delay device and the at least one second-pole controlled delay device has a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a first pair of antiparallel directions, and The surface alignment layer of the other of the at least one first-pole controlled delay device and the at least one second-pole controlled delay device has a pretilt angle, the pretilt angle having a pretilt angle direction having a component in the plane of the liquid crystal material layer in a second pair of antiparallel directions, the first pair of antiparallel directions intersecting the second pair of antiparallel directions.

27. The display device of claim 26, wherein, viewed from a plane orthogonal to the liquid crystal material layer of the at least one first-pole control delay unit and the at least one second-pole control delay unit, the first pair of antiparallel directions are at 90 degrees to the second pair of antiparallel directions.

28. The display device of claim 26, wherein the switchable liquid crystal delay of one of the at least one first pole control delay device and the at least one second pole control delay device has a delay for light with a wavelength of 550 nm, the delay having a first delay value, and the switchable liquid crystal delay of the other of the at least one first pole control delay device and the at least one second pole control delay device has a delay for light with a wavelength of 550 nm, the delay having a second delay value, the first delay value being greater than the second delay value.

29. The display device of claim 28, wherein the magnitude of the difference between half of the first delay value and the second delay value is at most 400 nm.

30. The display device according to claim 26, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, which have a retarding of light with a wavelength of 550 nm in the range of 450 nm to 900 nm. The other of the at least one first-pole controlled delayer and the at least one second-pole controlled delayer further includes a pair of passive single-axis delayers having intersecting optical axes in the plane of the delayers, and each having a delay in the range of 250 nm to 800 nm for light with a wavelength of 550 nm.

31. The display device according to claim 26, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide uniform alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, and The other of the at least one first-pole controlled delay unit and the at least one second-pole controlled delay unit further includes a passive single-axis delay unit having an optical axis perpendicular to the plane of the delay unit and having a delay in the range of -300nm to -700nm for light with a wavelength of 550nm.

32. The display device according to claim 26, wherein Regarding the other of the at least one first-pole controlled retarder and the at least one second-pole controlled retarder, the two surface alignment layers are arranged to provide a vertical alignment in adjacent liquid crystal materials, the adjacent liquid crystal materials having a retardation of light with a wavelength of 550 nm in the range of 500 nm to 900 nm, and The other of the at least one first-pole controlled delay unit and the at least one second-pole controlled delay unit further includes a passive single-axis delay unit having an optical axis perpendicular to the plane of the delay unit and having a delay in the range of -300nm to -800nm ​​for light with a wavelength of 550nm.

33. The display device of claim 26, wherein the spatial light modulator includes an emitting spatial light modulator arranged to output light, the display polarizer is an output display polarizer arranged on the output side of the emitting spatial light modulator, the second additional polarizer is arranged on the output side of the spatial light modulator, outside the first additional polarizer, and the at least one second pole control delay unit is arranged between the first additional polarizer and the second additional polarizer.

34. The display device according to claim 33, wherein The emitted spatial light modulator includes a pixel array arranged in a pixel layer, and The display device further includes a parallax barrier forming an array of apertures, wherein the parallax barrier is spaced apart from the pixel layer by a parallax distance along an axis of the normal to the plane of the pixel layer, and each pixel is aligned with an aperture.

35. The display device of claim 34, wherein the emitting spatial light modulator and the parallax barrier have an output brightness curve having a full width at half maximum (FWHM) of up to 40 degrees.

36. The display device of claim 26, wherein the display device further comprises a backlight source arranged to output light, and the spatial light modulator comprises a transmission spatial light modulator arranged to receive the output light from the backlight source.

37. The display device according to claim 36, wherein the backlight has an output brightness curve having a full width at half maximum (FWHM) of up to 40 degrees.

38. The display device of claim 1, wherein the spatial light modulator includes an emitting spatial light modulator arranged to output light, the display polarizer is an output display polarizer arranged on the output side of the emitting spatial light modulator, the second additional polarizer is arranged on the output side of the spatial light modulator, outside the first additional polarizer, and the at least one second pole control delay unit is arranged between the first additional polarizer and the second additional polarizer.

39. The display device of claim 1, wherein the display device further comprises a backlight source arranged to output light, and the spatial light modulator comprises a transmissive spatial light modulator arranged to receive the output light from the backlight source.

40. The display device of claim 1, wherein the other of the at least one first-pole control delay unit and the at least one second-pole control delay unit further comprises at least one passive compensation delay unit.

41. The display device of claim 40, wherein the at least one passive compensation delay of the other of the at least one first-pole control delay and the at least one second-pole control delay comprises: A passive single-axis delayer, the passive single-axis delayer having an optical axis perpendicular to the plane of the passive single-axis delayer; or A pair of passive single-axis delayers, the passive single-axis delayer pair having intersecting optical axes in the plane of the passive single-axis delayer.

42. The display device of claim 1, wherein, with respect to the other of the at least one first pole control delay and the at least one second pole control delay, the two surface alignment layers are arranged to provide vertical alignment in adjacent liquid crystal materials.

43. The display device of claim 42, wherein the display device further comprises a backlight arranged to output light, the spatial light modulator comprises a transmissive spatial light modulator arranged to receive the output light from the backlight, and the other of the at least one first pole control delay unit and the at least one second pole control delay unit is located between the backlight and the transmissive spatial light modulator.

44. The display device of claim 1, wherein, with respect to the other of the at least one first pole control delay and the at least one second pole control delay, the two surface alignment layers are arranged to provide surface alignment in adjacent liquid crystal materials.

45. The display device according to claim 16, 17, 24, 25, 36, 37, 39 or 43, wherein: The display polarizer is an input display polarizer arranged on the input side of the spatial light modulator; The first additional polarizer is arranged between the backlight and the input display polarizer; and The second additional polarizer is arranged on the same side of the spatial light modulator as the first additional polarizer, between the backlight and the first additional polarizer, and the at least one second pole control delay is arranged between the first additional polarizer and the second additional polarizer.

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