Device for controlling visible light transmittance

Abstract

The present invention discloses an apparatus comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having orthogonal first and second polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically connected in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; the first cell comprising individually switchable pixel regions within a common switching region of the second cell.

Description

Technical Field

[0001] This application relates to an apparatus for controlling the transmittance of visible light, an assembly including the apparatus and at least one optical component, a device including the apparatus, a processor and a memory including instructions for controlling the apparatus, and a method of operating such an apparatus. Background Technology

[0002] Some optical applications benefit from the ability to adjust the transmittance of incident visible light between different regions of the viewing plane. One technique involves using pixelated optical components that exhibit polarization-dependent absorption characteristics, and using two such pixelated optical components optically tandem (each for one of two orthogonal polarizations) together to adjust the transmittance of unpolarized light. Summary of the Invention

[0003] The inventors of this application have conceived different methods. Attached Figure Description

[0004] As an example only, the example is described in detail below with reference to the accompanying drawings, in which:

[0005] Figure 1 A representation of an example of the components of a dimmer device;

[0006] Figure 2 Another representation of an example of components of a dimmer device;

[0007] Figure 3 A representation of an example of the electrodes of a dimmer device;

[0008] Figure 4 A representation of an example head-mounted kit showing an example of a dimmer device;

[0009] Figure 5 Demonstration for operation Figure 4 A representation of an instance of a head-mounted device system; and

[0010] Figure 6 An example of the equipment is shown schematically. Detailed Implementation

[0011] An apparatus is provided comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having orthogonal first and second polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically connected in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; the first cell comprising individually switchable pixel regions within a common switching region of the second cell.

[0012] The first cell may be contained within a pixel electrode array in the common switching region of the second cell.

[0013] Only one of the first cell and the second cell may contain an independently addressable pixel electrode array.

[0014] The first cell can be a pixelated cell, and the second cell can be a global cell.

[0015] The first cell may contain dye molecules that can be electrically switched between at least the first mode and the second mode, and the second cell may contain dye molecules that can be electrically switched between at least the third mode and the fourth mode.

[0016] The first cell and the second cell can be a mixture of the dye molecules and liquid crystal material molecules, and the orientation of the dye molecules is determined by an electrically switchable orientation of the liquid crystal molecules.

[0017] The first cell and the second cell can be vertically aligned liquid crystal cells.

[0018] The first cell and the second cell can be electrically controlled birefringent liquid crystal cells.

[0019] The device may further include: a first pair of film components in the first cell, wherein on either side of the mixture of dye molecules and liquid crystal material molecules, one film component supports an individually addressable pixel electrode array on one side of the mixture, and the other film component supports a common blanket electrode on the other side of the mixture; and a second pair of film components in the second cell, wherein on either side of the mixture of dye molecules and liquid crystal material molecules, each film component supports a blanket electrode on either side of the mixture.

[0020] An assembly is provided, comprising: a device including: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having orthogonal first and second polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically connected in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; and at least one additional optical component.

[0021] The at least one additional optical component may include at least one of the following: a waveguide, a brightness adjustment component, a lens, an image generating device, a reflection reduction layer, or a protective layer.

[0022] A device is disclosed comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having orthogonal first and second polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically connected in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; at least one processor; and at least one memory containing instructions configured to cause the device to switch the first cell between the first mode and the second mode, and to switch the second cell between the third mode and the fourth mode, by means of the at least one processor.

[0023] The device can be installed on a human head by assembling the first cell and the second cell in a field of view of one eye of the human head.

[0024] The device may include: a first lens including a first lens on the first cell and the second cell, and a second lens including a second lens on the first cell and the second cell.

[0025] The field of view of the eye can be a first field of view of a first eye, the first lens can be assembled to be positioned in the first field of view during use, and the second lens can be positioned in a second field of view of a second eye of the human head during use.

[0026] The device may be at least one of the following: an augmented reality display device, a virtual reality display device, or a mixed reality display device.

[0027] A method of operating a device is disclosed, the device comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having orthogonal first and second polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically connected in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; the first cell comprising individually switchable pixel regions within a common switching region of the second cell, the method comprising: operating the first cell in the first mode for at least one of the pixel regions, and simultaneously operating the first cell in the second mode for at least one of the pixel regions.

[0028] The method may further include electrically switching the dye molecule of the first cell between at least the first mode and the second mode; and electrically switching the dye molecule of the second cell between at least the third mode and the fourth mode. It should be understood that other states may be provided by any two or more combinations of the states described above.

[0029] Various other configurations are also described in the following embodiments and the appended claims.

[0030] refer to Figures 1 to 3 According to some examples, the dimmer device comprises two object-subject liquid crystal (LC) cells A and B optically connected in series. Figure 1 The object-subject cell A is displayed on the front side of the device, but alternatively, the object-subject cell B may be displayed on the front side of the device.

[0031] Each guest-host LC cell A and B comprises a mixture of liquid crystal molecules and dichroic (or negative dichroic) dye molecules in corresponding volumes of 10 and 12 contained between corresponding pairs of membrane assemblies 2, 4 and 6, 8. Membrane assemblies 2, 4, 6, 8 each comprise a corresponding support membrane (e.g., an organic polymer / plastic membrane) 22, 24, 26, 28 supporting at least corresponding electrodes 14, 16, 18, 20 for switching the LC-dye mixture between at least two modes. Support membranes 22, 24, 26, 28 support other components not shown in the figure, such as circuitry for addressing electrodes 14, 16, 18, 20, and sealants / adhesives for bonding the membrane assemblies of the cells together and laterally enclosing the LC / dye mixture. The support films 22, 24, 26, and 28 may also support, for example, LC alignment layers (e.g., rubbed polyimide (PI) layers) that interface with LC / dye mixtures 10 and 12, and spacers formed in situ on the support films 22, 24, 26, and 28 to increase the uniformity of the thickness of the LC-dye mixtures 10 and 12 across the entire working area.

[0032] Dye molecules immediately exhibit a change in orientation after the orientation of liquid crystal molecules changes. The degree to which dye molecules absorb visible light depends on the orientation of the dye molecules and the polarization of the light. For positive dichroic dyes, they exhibit greater absorption for light with an electric field parallel to the long axis of the dye molecules than for light with an electric field perpendicular to the long axis of the dye molecules; and for negative dichroic dyes, the opposite is true.

[0033] Cell A can be electrically switched between at least a transmission mode and a dimming mode. The transmission mode is used to transmit visible light having both orthogonal first and second polarizations, and the dimming mode exhibits a greater reduction in transmittance for visible light with the first polarization compared to visible light with the second polarization (relative to the transmission mode). Cell B can also be electrically switched between at least a transmission mode and a dimming mode. The transmission mode is used to transmit visible light having both orthogonal first and second polarizations, and the dimming mode exhibits a greater reduction in transmittance for visible light with the second polarization compared to visible light with the first polarization (relative to the transmission mode).

[0034] Cell A is a pixelated cell, and cell B is a global cell.

[0035] Cell A comprises an array of individually addressable pixel electrodes 14 on one side of the LC-dye mixture 10 and a common blanket electrode 16 on the other side of the LC-dye mixture 10. The array of individually addressable pixel electrodes 14 allows the LC-dye mixture 10 to vary the transmittance (for visible light with first polarization) of one or more other pixel regions relative to those regions. Each of the pixel electrodes 14 in the pixel electrode array can be individually addressed by a passive matrix circuitry or an active matrix circuitry. According to another embodiment, the pixels can be directly addressed by a direct-drive (segmented) circuitry (without any matrix) including dedicated addressing conductors for each pixel. Electrical switching of the pixel regions in cell A is achieved by changing the potential across the respective pixel electrodes 14 and the common electrode.

[0036] Cell B comprises common blanket electrodes 18, 20 on both sides of the LC-dye mixture 12. For cell B, no pixelation is used to switch the transmittance of the LC-dye mixture 12 (for visible light with a second polarization). Switching of cell B is limited to switching the entire region of the pixel electrode array covering the entire cell A. Electrical switching of the cell is achieved by changing the potential of the electrodes 18, 20 across the cell on opposite sides of the LC-dye mixture in cell B.

[0037] According to one example, the transmittance of cells A and B can be reduced (for visible light with corresponding polarization) by similarly changing the potential across LC-dye mixtures 10 and 12.

[0038] For example, LC cells A and B can be vertically aligned (VA) type LC cells, and the transmittance of cells A and B can be reduced by changing the relatively small (e.g., zero) potential across LC-dye mixtures 10 and 12 to a larger potential across LC-dye mixtures 10 and 12.

[0039] Table 1 below shows the total output of individual pixel regions for four combinations of electrical inputs for two cells A and B.

[0040] Global cell B Individual pixels in pixelated cell A Total transmittance of individual pixel regions Disconnect (clear) Disconnect (clear) high Connect (in darkness) Connect (in darkness) Low Disconnect (clear) Connect (in darkness) medium Connect (in darkness) Disconnect (clear) medium

[0041] Table 1

[0042] Disconnect the substantially zero potential across the LC-dye mixture and connect the larger potential across the LC-dye mixture.

[0043] Alternatively, cells A and B can be electrically controlled birefringent (ECB) type cells, and the reduction in transmittance can be achieved by changing the larger potential across LC-dye mixtures 10 and 12 to a smaller potential across LC-dye mixtures 10 and 12 (e.g., substantially zero).

[0044] Table 2 below shows the total output of individual pixel regions for four combinations of electrical inputs for two cells A and B.

[0045] Global cell B Individual pixels in pixelated cell A Total transmittance of individual pixel regions Disconnect (Darkness) Disconnect (Darkness) Low Connect (Clear) Connect (Clear) high Disconnect (Darkness) Connect (Clear) medium Connect (Clear) Disconnect (clear) medium

[0046] Table 2

[0047] Next, disconnect the substantially zero potential across the LC-dye mixture and connect the larger potential across the LC-dye mixture.

[0048] For example, the test apparatus achieved total transmittance values ​​of approximately 18.5%, 44%, and 65% for dark / dark, dark / clear, and clear / clear combinations, respectively.

[0049] As will be discussed below, a dimmer device can form part of an augmented reality (AR) headset. When the headset is used in bright outdoor conditions, it can be useful to put global cell B in dark mode. Cell A pixels in the area where the light engine presents virtual objects to the user of the headset are then in dark mode, and cell A pixels in the area where the light engine does not present virtual objects to the user are then in clear mode.

[0050] When the AR headset is used in moderate lighting conditions or dim indoor conditions, it can be useful to put global cell B in clear mode. Depending on whether the light engine needs assistance from a dimmer device to clearly present virtual objects to the user against a real background, the pixels of cell A in the area where the light engine presents virtual objects to the user of the headset can then be in either dark or clear mode.

[0051] In one example, global cell B in dark mode exhibits a greater reduction in transmittance for vertically polarized visible light than for horizontally polarized visible light, and pixelated cell A in dark mode exhibits a greater reduction in transmittance for horizontally polarized visible light than for vertically polarized visible light. Pixels operating cell B in dark mode and cell A in clear mode thus provide the same type of glare reduction effect for those pixel areas as polarized sunglasses.

[0052] The above description mentions switching between two modes (maximum transmission mode and minimum transmission mode), but the technology can be extended to switch between one or both of the two cells A and B between more than two modes (including an intermediate transmission mode between the maximum transmission mode and the minimum transmission mode).

[0053] Compared to the method of providing two optically tandem pixel cells, the dimmer device described above requires a less stringent alignment procedure for its assembly. Furthermore, for instances of pixel cell types containing a black matrix (such as active matrix pixel cells), reducing the number of pixel cells from two to one can provide a dimmer device exhibiting less parallax.

[0054] The dimmer device described above can be used, for example, in a liquid crystal device such as a switchable lens device or a beam steering device. For instance, the device may be or include an adaptive optical lens comprising a liquid crystal device including a dimmer device according to any of the examples herein. Such a device may be or include a head-mounted device, which may be referred to as a head-mounted display (HMD).

[0055] Liquid crystal devices, including the dimmer devices described above, are suitable for a wide range of applications, including eye lenses (such as spectacle lenses), virtual reality (VR), mixed reality (MR) and augmented reality (AR) head-mounted devices; optical projectors; photographic devices; and communication devices.

[0056] Dimmer devices can be used in augmented reality (AR) head-mounted kits, such as Figure 4 The headgear shown. Figure 4 A representation of an AR head-mounted kit that displays and includes the dimmer device described above.

[0057] The headgear 40 includes a support frame 42 that supports optical components arranged in optical series in front of the user's eyes.

[0058] At least one optical component, such as Figure 4 One or more of the optical components shown herein may be considered to correspond to or be part of an assembly that may be considered to include a display stack containing at least one liquid crystal cell according to the examples herein. In, for example... Figure 4 In some instances, such assemblies include stacks of liquid crystal cells according to the examples herein. Figure 4 In one example, the push lens 48a includes at least one stack of liquid crystal cells, the pull lens 48b includes at least one stack of liquid crystal cells, and the assembly includes the push lens 48a, the waveguide 50, the pull lens 48b, the variable dimmer device 46 (which is an example of a brightness adjustment assembly), and the front window / lens 44.

[0059] The stacked liquid crystal cells can be aligned along a common optical axis. However, in some cases, the optical axes of at least two of the stacked liquid crystal cells can be offset from each other in a direction parallel to the plane of the radial electrode pattern of at least one of the liquid crystal cells, subject to the condition that light traversing the assembly traverses the stacked liquid crystal cells. Figure 4For clarity, only the optical components for one half of the head-mounted kit are shown, but a matching set of optical components for the other half of the head-mounted kit is also provided.

[0060] The waveguide 50 of the head-mounted device displays the left and right perspectives of one or more virtual reality objects, allowing the user to perceive these objects as 3D objects. Alternatively, other mechanisms, such as laser projection, can be used to display the left / right perspectives of one or more virtual reality objects.

[0061] The user's left and right eyes need to rotate relative to each other so that the left and right perspectives of the virtual reality object are simultaneously guided to the fovea (the part of the retina that is responsible for clear central vision, which is essential for activities crucial to visual detail) of the user's corresponding left and right eyes to determine the distance of the virtual reality object perceived by the user. This mechanism is called "vergence".

[0062] The LC optical lens device described above can be used as an adaptive lens device to control the position of the left / right viewpoint of the displayed virtual reality object so that the user's eye perceives the focal plane (i.e., without blurring). In other words, the LC optical lens device described above can be used as an adaptive lens device to control the degree to which the lens in the user's eye needs to adapt to the left and right viewpoints of the virtual reality object so that the user's eye perceives the focal plane (i.e., without blurring). This adaptive mechanism of the lens in the user's eye is called accommodation.

[0063] The LC optical lens device described above can be used to substantially generate optical images (real or virtual) of a virtual reality object from the left / right perspective at a certain distance from the user's eyes, which the user perceives as being at that distance through the convergence mechanism discussed above. This allows the user to perceive a focused 3D image of the virtual reality object without disrupting the convergence-accommodation reflection, through which the focusing effect (accommodation) of the lens in the user's eyes is unconsciously associated with the aforementioned rotation (convergence) of the left and right eyes relative to each other. In other words, the LC optical lens device can be used to avoid or reduce eye strain caused by the conflict between the convergence and accommodation mechanisms (referred to as convergence-accommodation conflict).

[0064] The liquid crystal device described in the examples herein can provide a less complex and / or higher-quality system to actively adjust focus to compensate for the focal discrepancy between virtual objects and the real-world environment visible to the user of the head-mounted device via optical components mounted in front of each eye. This, for example, allows for a consistent combination of perceived and actual image depth, thereby improving user comfort.

[0065] exist Figure 4 In this device, the head-mounted device 40 allows light from the real-world environment surrounding the device to be at least partially transmitted through optical components and reach the user's eyes. In this example, the optical components are at least partially transparent. On a sunny day, the ambient light level outdoors can be significantly higher than indoors, such as approximately 100 times higher. When a user operates the head-mounted device outdoors, this can cause virtual objects to fade and become difficult to see unless the light level transmitted from the environment to the user is properly controlled. Figure 4 In this device, the variable dimmer device 46 controls the amount of light transmitted through the optical components toward the eyes, for example, to reduce the brightness of light transmitted from the environment toward the user under bright conditions, and can be used to provide ambient dimming to dim the ambient light transmitted through the head-mounted device 40.

[0066] The variable dimmer device 46 provides so-called global dimming, wherein the brightness of light from the environment is adjusted by substantially the same amount across the plane of the variable dimmer device 46 facing the user (e.g., to reduce the brightness of light by substantially the same amount across the entire surface area of ​​the variable dimmer device 46). In other words, global dimming allows for substantially spatially uniform control of the brightness of light transmitted through the variable dimmer device 46 (e.g., to provide a substantially spatially uniform reduction in brightness across the user's field of view).

[0067] The variable dimmer device 46 may also or alternatively provide local dimming, wherein the variable dimmer device 46 is adjustable to control the brightness of light transmitted from the ambient light on a zone-by-zone basis (where a zone may correspond to a single pixel or multiple pixels). Variable dimming may involve adjusting brightness across the entire surface area smaller than the variable dimmer device 46, such as adjusting brightness in a sub-region smaller than the surface area of ​​the variable dimmer device 46. However, in other cases, local dimming may involve adjusting brightness across the entire surface area of ​​the local dimmer device 46, but adjusting different amounts in at least two portions of the surface area.

[0068] although Figure 4 Not shown, but it should be understood that the head-mounted device 40 can be configured to obtain, for example, light intensity data indicating the brightness of light in the environment surrounding the head-mounted device 40, from a light sensor within the head-mounted device 40. For example, if a first side 49a of the head-mounted device 40 is configured to face the user, wherein the head-mounted device 40 is mounted on the user's head, the head-mounted device 40 may include a light sensor to detect the brightness of light at a second side 49b of the head-mounted device 40 opposite the first side 49a. The variable dimmer device 46 may be controlled, at least in part, based on the brightness data, to adjust the brightness of light transmitted from the second side of the head-mounted device 40 toward the user, thereby improving the visibility of virtual objects displayed to the user by the head-mounted device 40.

[0069] exist Figure 4 In one example, a first lens (push lens 48a) comprising at least one stack of liquid crystal cells, as described herein, is located between the waveguide 50 and the eye, wherein the head-mounted device 40 is in use. Light representing a virtual object is generated and transmitted to the waveguide 50, which guides the light through the push lens 48a and to the eye. The push lens 48a has a focusing effect that focuses the light representing the virtual object so that the object is presented to the user in focus. For example, a virtual object may be generated such that it is in focus at a focal plane at infinity. The push lens 48a may then focus the virtual object at a focal plane closer to the user than infinity, allowing the user to focus more comfortably on the virtual object. The focal plane in which the virtual object will be focused and the magnification thus applied by the push lens 48a may be determined based, for example, eye-tracking data obtained by a suitable sensor, as discussed further below, indicating the direction in which the user's eyes are looking.

[0070] Before using the head-mounted device 40, the external environment is presented to the user in a focused manner. However, in the absence of the pulling lens 48b, light from the external environment will at least partially pass through the waveguide 50 and through the pushing lens 48a, and will therefore undergo a focusing effect provided by the pushing lens 48a. This will distort the external environment as viewed by the user through the head-mounted device 40. To compensate for the distortion introduced by the pushing lens 48a, Figure 4 The head-mounted device 40 includes a second lens (pull lens 48b) positioned on the side of waveguide 50 opposite to the push lens 48a. The pull lens 48b applies an appropriate focusing effect to light from the environment passing through it, to at least partially compensate for or otherwise reduce the focusing effect introduced by the push lens 48a. For example, the push lens 48a and pull lens 48b may provide opposite focusing effects, such as being substantially equal in magnitude but opposite in sign. As an example, one of the push lens 48a and pull lens 48b may provide a positive focusing magnification, and the other may provide a negative focusing magnification, the positive and negative focusing magnifications being substantially equal in magnitude.

[0071] In the examples described herein, at least one lens (such as at least one of a pushing lens 48a and a pulling lens 48b, and in some cases, both pushing lens 48a and pulling lens 48b) each comprises a so-called doublet lens of a liquid crystal cell according to the examples described herein. A doublet lens is a stack of two liquid crystal cells. The focusing effect of a liquid crystal-based lens can depend on the polarization of the light incident on the lens. Instead of using a separate polarizer assembly, using a doublet lens such as this can provide a suitable focusing effect and improved light transmission; in some examples, this is achieved by orthogonally positioning one liquid crystal cell of the doublet lens relative to the other liquid crystal cells to modify the corresponding polarization orientation of the light.

[0072] Figure 4 Examples of push lens 48a and pull lens 48b combined with various other optical components are shown. It should be understood that the liquid crystal cell according to the examples herein can be combined with different... Figure 4 The optical components shown herein are used in combination to provide further flexibility in functionality. This can further reduce the size and / or weight of devices including liquid crystal cells and / or improve the optical performance of the devices. For example, an assembly including liquid crystal cells according to the examples herein (such as a display stack) may include a reflection reduction layer (such as an anti-reflective (AR) coating) that may be laminated to another optical component of the assembly (such as a front window / lens 44); and / or a protective layer (such as a hard coating) for protecting the assembly from damage, for example, due to abrasion and / or wear due to exposure to environmental conditions.

[0073] refer to Figure 5 According to some examples, system 55 includes processor 51, which operates based on computer program code stored in memory 52 to control image generation driver chip 53 so that the image generation system generates images of one or more virtual reality objects from the left / right perspective, through which the user can perceive 3D images of virtual reality objects and display the images via waveguide 50.

[0074] although Figure 5 Not shown in the text, but it should be understood that there can be two waveguides: one waveguide displays the left-view image of the virtual reality object to the left eye, and the other waveguide displays the right-view image of the virtual reality object to the right eye, as shown in the reference. Figure 5 Further discussion follows. It is possible to have two image generation systems: one image generation system generates an image of the virtual reality object from the left perspective, and the other image generation system generates an image of the virtual reality object from the right perspective (however, in some cases, a single image generation system may generate two images, or an image generation system may generate a single image to be displayed to both eyes). The image generation systems are referenced below. Figure 6Further discussion follows. Input from the sensors is fed into the processor, enabling the processor to control the position of virtual reality objects displayed by waveguide 50, for seamlessly overlaying one or more virtual reality objects onto the user's view of the real environment.

[0075] Based on inputs from one or more sensors 54 that sense the movement of the user's eyes and / or based on the content displayed by the waveguide 50, the processor 51 controls the adaptive lens driver chip 38 to achieve the optical focusing magnification (diopter) required for the aforementioned generation of the optical image of the waveguide's display output at a distance from the user's eyes, at which the virtual content determined by the user to be viewing (e.g., by tracking the user's eyes) is intended to be perceived by the user (via the convergence mechanism described above). The driver chip is an example of a controller, which may be implemented in hardware, for example, via a suitably configured circuit system. In some cases, the driver chip may include or be considered to implement at least one processor.

[0076] Figure 6 The hardware architecture of device 60 according to another example is schematically illustrated. Device 60 includes at least one stack of liquid crystal cells according to the examples herein. Figure 6 In this configuration, device 60 is assembled for use and mounted on a human head, such as on a user's head, wherein the stacked liquid crystal cells are positioned within the field of view of the eyes. Figure 6 In one example, device 60 is an AR head-mounted device used to display virtual images to the wearer of the head-mounted device, and may be similar to or identical to [other devices]. Figure 4 The headgear 40. However, in other instances, including with Figure 6 Devices with similar hardware architectures to Device 60 can be assembled for different purposes and may include additional components and / or omissions. Figure 6 At least one of the components shown in the figure.

[0077] Figure 6 The device 60 includes an optical system 62, an image generation system 64, at least one processor 66, a memory 68, at least one sensor 70, a user input / output interface 72, a communication system 74, and at least one additional hardware system 76. The components of the device 60 are interconnected via at least one bus 78, which may be or include any suitable interface or bus for transmitting data between the illustrated components.

[0078] The optical system 62 includes a first assembly and a second assembly, which in this example are a first display stack 62a and a second display stack 62b, respectively. The first display stack 62a includes, for example, a first set of optical components configured in a layered stack. The device 60 is configured to allow light from the external environment, when in use and mounted on the head, to be at least partially transmitted through the first display stack 62a and toward the user's first eye. In other words, the device 60 has a first side configured to face the user in use (e.g., ...). Figure 4 In the case of the first side 49a), the first display stack 62a is configured to direct light from the second side to the first eye (in this case, via the first display stack 62a). In this case, the first display stack 62a includes the optical components shown in FIG. X, namely, a push lens 48a, a waveguide 50, a pull lens 48b (where the push lens 48a and the pull lens 48b are each examples of a liquid crystal device according to the examples herein), a variable dimmer device 46, and a front window / lens 44. The push lens 48a and / or the pull lens 48b of the first display stack 62a can be regarded as a first lens containing at least one of the first liquid crystal cell stacks according to the examples herein. The first lens is assembled to be positioned in the first field of view of the first eye (e.g., the user's first eye) during use.

[0079] exist Figure 6 In this embodiment, the second display stack 62b includes a second set of optical components, which in this example are identical to the first set of optical components but are configured to transmit light toward the user's second eye when the device 60 is in use. In other words, the second display stack 62b is configured to direct light from a second side of the device 60 toward the second eye. Therefore, in this example, the push lens and / or pull lens of the second display stack 62b can be considered as a second lens including at least one of the second components in the liquid crystal cell stack according to the embodiment herein. The second lens is configured to be positioned in the second field of view of the second eye (e.g., the user's second eye) during use. It should be understood that the first lens may be visible only to the first eye or to both the first and second eyes during use, and the second lens may be visible only to the second eye or to both the first and second eyes during use.

[0080] The spatial arrangement of the components of the second display stack 62b in at least one layer of the stack may be a mirror image of the spatial arrangement of the corresponding components of the first display stack 62a in the corresponding layer of the first optically configured stack 62a, as reflected in the sagittal plane of the device 60 (which may be referred to as the longitudinal plane of the device 60, and for example, separates the left and right sides of the device in use). However, in other cases, the first display stack 62a and the second display stack 62b may have different structures from each other. It should be understood that the optical system 62 may include additional components, such as Figure 6 Other optical components not shown in the image.

[0081] Device 60 also includes an image generating system 64 for generating an image of a virtual object to be displayed to a user of device 60, such that the virtual object appears to the user as an overlay on top of an external environment at least partially visible to the user via optical system 62. Image generating system 64 may be or include a display device for generating images (e.g., images of virtual objects) for display by device 60 to the user. The display device may be a liquid crystal display (LCD), a light-emitting diode (LED) display device (such as an organic light-emitting diode (OLED) display device), an electroluminescent (EL) display device, etc. Figure 6 In this example, the image generating system 64 communicates optically with the optical system 62. For instance, if device 60 is in... Figure 4 In the form of a head-mounted device 40, the image generation system 64 can be housed by a support frame 42. Light representing virtual objects generated by the image generation system 62 can be transmitted directly (e.g., without traversing another optical component) or via at least one additional optical component to the optical system (e.g., transmitted to a structure such as...). Figure 4 (The waveguide 50 shown is a waveguide). In some cases, the image generation system may include two display devices, a first display device for a first eye and a second display device for a second eye, for example, when it is necessary to display a first image to the first eye and a second image to the second eye. In other instances, a single display device may be used to generate an image to be displayed to both the first and second eyes.

[0082] exist Figure 6 In one example, the image generating system 64 is shown as a system separate from the optical system 62. However, in other examples, the image generating system may be part of the optical system. For instance, an assembly of the optical system (such as a display stack) may include the image generating system, such as a display device.

[0083] The at least one processor 66 of the device 60 may be a single processor or a plurality of processors of one or more types. Components of the at least one processor 66 may be implemented using suitably programmed hardware, for example, in the form of a circuit system. The at least one processor 66 may include a central processing unit (CPU), a graphics processing unit (GPU), and / or a neural processing unit (NPU), which may be referred to as a neural network accelerator.

[0084] In some instances, devices, such as Figure 6 The device 60 includes a drive circuit system connected to at least one electrical connection to an electrode pattern of a liquid crystal cell stack to apply a potential difference across one or more sets of electrodes of the liquid crystal cells of the liquid crystal cell stack. The applied potential difference (such as the magnitude and / or timing of the applied potential difference) may be determined by at least one processor 66 and / or by the drive circuit system, such as a controller implemented by at least a portion of the drive circuit system, based on instructions stored in a memory.

[0085] If the potential difference is determined by the driving circuitry system, the determination of the potential difference can be initiated by instructions received from at least one processor, such as instructions indicating that a virtual object will be displayed and one or more electrode sets will therefore be activated so that the virtual object is presented to the user with focus. In this way, the driving circuitry system can be unknown to the at least one processor from which it receives instructions. In other words, the operation of the driving circuitry system can, for example, be independent of the at least one processor used to control the driving circuitry system, so that the same effect can be achieved regardless of the at least one processor coupled to the driving circuitry system (the limitation being that at least one processor provides appropriate instructions to the driving circuitry system so that the driving circuitry system determines a suitable potential difference).

[0086] A potential difference can be applied to an electrical connection by at least one driver of a drive circuit system, such as... Figure 5 The adaptive lens driver chip 38 is an example of a driver. Applying a potential difference by at least one driver can be considered equivalent to a so-called "driving" of an electrode pattern via an electrical connection. The driver circuit system may be in the form of at least one system-on-a-chip (SoC).

[0087] Memory 68 may be or may include volatile and / or non-volatile memory usable by a computer. Memory 68 may include random access memory (RAM) and / or read-only memory (ROM). Memory 68 may be removable from device 60 or non-removable. Memory 68 stores instructions for controlling device 60 according to the examples herein, such as activating one or more sets of electrodes of a stack of liquid crystal cells. For example, activating an electrode set refers to applying a potential difference between at least two terminals connected to the electrode set. The instructions may be in the form of computer-readable and / or executable instructions, such as computer program instructions. Although memory 68 is in Figure 6 The memory 68 is shown as a component separate from at least one processor 66, but in some cases, the memory 68 may be or include the internal memory of at least one processor 66, in which case at least one processor 66 and memory 68 may be at least partially integrated into the same system or component.

[0088] In this example, at least one sensor 70 is configured to acquire eye-tracking data of the device during use, such eye-tracking data indicating, for example, the direction in which at least one of the user's eyes is looking, as those skilled in the art will understand. Eye-tracking data may be acquired for each eye individually, or for a single eye of the user, or for a combination of both eyes of the user. Suitable sensors for acquiring eye-tracking data include: a camera 70a for acquiring an image of at least one of the user's eyes, an inertial measurement unit (IMU) 70b for determining the orientation of the device 60, and at least one position sensor 70c, such as a Global Positioning System (GPS) sensor, for determining the position of the device 60. As those skilled in the art will understand, the IMU 70b may include at least one accelerometer or gyroscope for determining the orientation of the device 60. The focusing effect of at least one liquid crystal cell may be controlled based on the eye-tracking data, for example, to reduce strain on the user's eyes, as further described above.

[0089] Device 60 also includes a user input / output interface 72 through which a user can interact with device 60 to control the state of device 60. For example, user input / output interface 72 may be or include input devices such as buttons, touch screens, sliders, controllers, or any other suitable means for transmitting user requests to device 60 to control device 60.

[0090] Device 60 includes a communication system 74 for receiving data from a remote system, for example, via a suitable telecommunications network (such as a wireless network) or via some other type of network or connection. Communication system 74 may include input / output interfaces for receiving data from the remote system, such as a Bluetooth connector, a Universal Serial Bus (USB) connector, or a network connector.

[0091] Figure 6 The device 60 includes at least one additional hardware system 76, such as a power source, for supplying power to the electrical components of the device 60.

[0092] Some examples of optical focusing devices have been described above, but the same technology has been applied to other fields, such as beam steering optics.

[0093] Other examples relate to a method of operating an apparatus according to any of the examples in this document.

[0094] The term “substantially” as used in this article can be considered to mean two components that are “substantially” the same: the same within manufacturing tolerances, the same within measurement uncertainty, and / or within 5% of each other.

[0095] Apart from any modifications explicitly mentioned above, it will be apparent to those skilled in the art that various other modifications can be made within the scope of this invention to the described examples.

[0096] The applicant hereby discloses individually the various features described herein and any combination of two or more such features, within the following limits: such features or combinations are feasible based on the general knowledge of those skilled in the art, taking into account whether such features or combinations solve any of the problems disclosed herein, and without limiting the scope of the claims. The applicant indicates that embodiments of the invention may consist of any such individual features or combinations of features.

Claims

1. An apparatus comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having first and second orthogonal polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; the first cell comprising individually switchable pixel regions within a common switching region of the second cell.

2. The apparatus of claim 1, the first cell comprising an array of pixel electrodes within the common switching region of the second cell.

3. The apparatus of claim 1, only one of the first cell and the second cell comprising an independently addressable array of pixel electrodes.

4. The apparatus of claim 1, the first cell being a pixelated cell and the second cell being a global cell.

5. The apparatus of any preceding claim, the first cell comprising dye molecules electrically switchable between at least the first mode and the second mode; and the second cell comprising dye molecules electrically switchable between at least the third mode and the fourth mode.

6. The apparatus of any preceding claim, the first cell and the second cell comprising a mixture of the dye molecules and liquid crystal material molecules, the orientation of the dye molecules being determined by electrically switchable orientation of the liquid crystal molecules.

7. The apparatus of claim 6, the first cell and the second cell being homeotropic liquid crystal cells.

8. The apparatus of claim 6, the first cell and the second cell being electrically controlled birefringence liquid crystal cells.

9. The apparatus of any of claims 5 to 8, further comprising: a first pair of film assemblies in the first cell, one film assembly supporting an individually addressable array of pixel electrodes on one side of the mixture of dye molecules and liquid crystal material molecules, and the other film assembly supporting a common blanket electrode on the other side of the mixture; and a second pair of film assemblies in the second cell, each film assembly supporting a blanket electrode on either side of the mixture of dye molecules and liquid crystal material molecules.

10. An assembly comprising: an apparatus comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having first and second orthogonal polarizations, and the second mode exhibiting a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically in series with the first cell, wherein the second cell is electrically switchable between a third mode and a fourth mode, the third mode transmitting visible light having the first and second polarizations, and the fourth mode exhibiting a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; a second cell optically in series with the first cell, where the second cell is electrically switchable between a third mode that transmits visible light having the first polarization and the second polarization, and a fourth mode that exhibits a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode, at least one additional optical component.

11. The assembly of claim 10, wherein the at least one additional optical component includes at least one of: a waveguide, a luminance adjustment component, a lens, an image generating device, a reflection reduction layer, or a protective layer.

12. An apparatus comprising: a first cell electrically switchable between at least a first mode and a second mode, the first mode transmitting visible light having first and second orthogonal polarizations, and the second mode exhibiting a greater reduction in transmissivity for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically in series with the first cell, where the second cell is electrically switchable between a third mode that transmits visible light having the first polarization and the second polarization, and a fourth mode that exhibits a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode, at least one processor; and at least one memory including instructions configured to, by the at least one processor, cause the apparatus to switch the first cell between the first mode and the second mode, and to switch the second cell between the third mode and the fourth mode.

13. The apparatus of claim 12, configured to be mounted on a human head in a manner such that the first cell and the second cell are positioned in a field of view of one eye of the human head.

14. The apparatus of claim 13, comprising: a first lens including a first pair of the first cell and the second cell, and a second lens including a second pair of the first cell and the second cell.

15. The apparatus of claim 14, the field of view of the eye being a first field of view of a first eye, the first lens being configured to be positioned in the first field of view in use, and the second lens being positioned in a second field of view of a second eye of the human head in use.

16. The apparatus of any one of claims 12-15, wherein the apparatus is at least one of: an augmented reality display apparatus, a virtual reality display apparatus, or a mixed reality display apparatus.

17. A method of operating an apparatus, the apparatus comprising: a first cell electrically switchable between at least a first mode that transmits visible light having first and second orthogonal polarizations, and a second mode that exhibits a greater reduction in transmittance for visible light having the first polarization than for visible light having the second polarization relative to the first mode; and a second cell optically in series with the first cell, where the second cell is electrically switchable between a third mode that transmits visible light having the first polarization and the second polarization, and a fourth mode that exhibits a greater reduction in transmittance for visible light having the second polarization than for visible light having the first polarization relative to the third mode; the first cell including individually switchable pixel regions within a common switching region of the second cell, The method includes operating the first cell in the first mode for at least one of the pixel regions and simultaneously operating the first cell in the second mode for at least one of the pixel regions.

18. The method of claim 17, further comprising electrically switching the dye molecules of the first cell between at least the first mode and the second mode; and electrically switching the dye molecules of the second cell between at least the third mode and the fourth mode.

Images