Glasses display system for displaying a virtual image in a user's field of vision with aperture scanner

Abstract

The disclosure relates to a spectacle display system (1) for displaying a virtual image in a user's field of vision, comprising a display unit (14) for emitting light (163'', 161'', 162'') as computer-generated image information in a direction of emission; comprising a deflection unit (17) for deflecting the light (163'', 161'', 162'') emitted by the display unit (14) as computer-generated image information into an eye (10) of the user, comprising a plurality of micro-mirror elements (12, 12', 12'') which can each be tilted in a support structure and which each have a reflective surface (25) for deflecting the light (163'', 161'', 162'') emitted by the display unit (14) as computer-generated image information;wherein an aperture unit (70) arranged in an optical path of the light (163'', 161'', 162'') between the display unit (14) and the tiltable micro-mirror elements (12, 12', 12'') is adjustable by means of a control signal and is configured to adjust at least one beam position (70b', 70b'', 70b*) for the light deflected at the reflective surfaces (25) of the tiltable micro-mirror elements (12, 12', 12'') according to the control signal in order to provide a glasses display system (1) with improved immersion.

Description

Scope of the invention

[0001] The disclosure relates to a spectacle display system for displaying a virtual image in a field of vision of a user, comprising a display unit for emitting a light as computer-generated image information in an emission direction and comprising a deflection unit for deflecting the light emitted by the display unit as computer-generated image information into an eye of the user, comprising a plurality of micro-mirror elements, each tiltable in a support structure, which each have a reflection surface for deflecting the light emitted by the display unit as computer-generated image information. background

[0002] Glasses display systems for displaying a virtual image in a user's field of vision, known as "augmented reality glasses" or "AR glasses" for short, are able to overlay virtual objects in the form of virtual images onto the natural environment in the user's field of vision, thus virtually supplementing the field of vision. By displaying stereo images, these virtual objects can be placed freely in space. For this reason, it is advantageous to enable the largest possible field of vision that can be supplemented virtually and a display with high (angular) resolution in order to create an immersive feeling through permanent visibility and spatially consistent positioning of the virtual objects, namely the feeling that the virtual objects are physical objects. The weight of such glasses in particular contributes to the immersive feeling and can lead to an unnatural feeling for the user, especially when moving the head. The so-calledVergence accommodation problem is also a well-known effect that detracts from the immersive feeling.

[0003] The vergence accommodation problem exists in all 3D displays that show 3D objects using two stereo images. The 3D information, i.e., the distance of the object from the eye, is determined by the shifted stereo images. This distance conflicts with the distance at which the eye is focused to see a sharp image. A related problem arises in AR applications where virtual 3D objects are integrated into a real 3D environment. If the focus distance of the stereo image does not match the focus distance for the real environment, both scenes—the real and the virtual—cannot be viewed simultaneously, even though they are spatially fixed at the same location in the environment.

[0004] According to the state of the art, various optical methods are known for projecting a virtual image into the field of view of the natural environment. However, it is a technically unsolved problem to make the necessary optics small enough to achieve the form factor and weight of normal glasses. Glasses that are too large represent a technical limitation of the possible applications, since, for example, one would not accept a large product on the face in every everyday situation. If the weight is too great, AR glasses can only be worn for a limited time. Exemplary solutions are described in DE 10 2020 206 392 A1 or DE 10 2023 101 777 A1.

[0005] US Patent No. 10,623,707 B2 describes AR glasses with a high-resolution image for the central field of vision (fovea centralis) and a lower-resolution image area projected into the peripheral field of vision. For this purpose, the eye's gaze direction is measured using an eye-tracking sensor, and the projection optics are adjusted accordingly.

[0006] DE 10 2021 206 209 B3 describes AR glasses with micromirrors that are transparent to ambient light.

[0007] The publication US 2020 0186761 A1 presents AR glasses that allow the focal length of the AR optics to be adjusted to display objects at different distances. Thus, a technical solution to the vergence accommodation problem is revealed. US 2020 0186761 A1 also includes an eye-tracking module to measure the vergence eye parameters. Furthermore, it is proposed to use these measured values ​​to track the eye with the optics to enable eye tracking for different eye positions.

[0008] DE 10 2007 021 036 A1, JP 2011- 75 954 A and DE 10 2015 226 425 A1 disclose different aperture devices for stereoscopic displays.

[0009] The technical task is therefore to provide a glasses display system with improved immersion, in particular with minimized weight and the largest possible virtually augmentable field of view with the best possible image quality, as well as the possibility of addressing problems typical for AR glasses such as the vergence accommodation problem and / or the problem of visual acuity correction. overview

[0010] This problem is solved by the subject matter of the independent claim. Advantageous embodiments emerge from the dependent claims, the description, and the figures.

[0011] One aspect relates to a spectacle display system for displaying a virtual image in a user's field of vision, comprising a display unit for emitting light as computer-generated image information in a radiation direction and a deflection unit for deflecting the light emitted by the display unit as computer-generated image information into an eye of the user. The radiation direction runs in the direction of the user's field of vision (forward, thus the light is emitted into the field of vision). The deflection unit, with at least the micromirror elements mentioned below, is arranged in the user's field of vision (in front of the user's eye(s)) and serves to deflect the light back (backward) into the user's eye(s).

[0012] The deflection unit comprises a plurality of tiltable micro-mirror elements, each arranged in a support structure. Each of these elements has a reflective surface for deflecting the light emitted by the display unit as computer-generated image information into the user's eye. The reflective surface is permeable to ambient light emitted from the environment in front of the user in their field of vision toward the eye. The reflective surfaces can therefore be considered semi-transparent mirror surfaces.

[0013] A multitude of micromirrors can be understood here, for example, as at least 20, at least one hundred, or at least one thousand micromirrors. The reflecting surfaces are small, as is typical for micromirrors, for example, <100 mm. 2 or <20mm 2Since the micromirrors are movably mounted in the support structure, the reflective surfaces can each be aligned with their angular orientation in two dimensions. This means that the light emitted by the display unit, the light from the display unit, can be redirected into the eye or pupil for different orientations and / or positions of the eye. Since the deflection unit is at least partially (i.e. partially or completely), in particular with the micromirror elements, arranged in an optical path of ambient light from the user's field of vision into the user's eye, the virtual image corresponding to the computer-generated image information in the user's field of vision can be overlaid with real objects in the environment, since the micromirror elements are at least partially transparent to light from the environment (ambient light) (as required for AR glasses).For a better immersive feeling with virtual images that are as large as possible and as free of artifacts as possible, the deflection unit and / or the display unit are controlled depending on the orientation of the eye(s), for example with the control unit described below.

[0014] Advantageously, all micro-mirror elements (in particular always and / or predominantly) are angularly aligned such that only light from the display unit can be directed into the user's eye. This has the advantage that no light source placed elsewhere leads to a visible reflection in the eye. This avoids annoying light reflections that are visible as ghost images. This is particularly advantageous for applications in outdoor environments, where the sun, as a very bright light source, can lead to otherwise unpleasant stray light reflections. A resulting further advantage is that a high reflectance, for example a semi-transparent coating, can be selected for the reflective surfaces of the micro-mirror elements, since even with high reflectance, unwanted light reflections in the eye cannot be amplified.

[0015] The display unit can have one or more preferably flat screen elements ("displays") for generating the light, but also one or more (laser) projector elements. In particular, the display unit can be a stereo display unit suitable for generating a virtual stereo image in the field of vision. For this purpose, the stereo display unit can have two screen elements or two (laser) projector elements, each of which is assigned to one of the user's two eyes. For example, the screen elements or (laser) projector elements can each be arranged on a temple unit of the spectacle display system on the side of the user.

[0016] In one embodiment, it can be provided that the micro-mirror elements and the support structure are arranged in a sealed housing element of the deflection unit that is filled with a liquid. The housing element can be arranged in front of the user's eyes, similar to the lenses of conventional eyeglasses. Accordingly, the liquid, the micro-mirror elements, and the support structure are arranged in an interior of the housing element such that the micro-mirror elements and the support structure are surrounded by the liquid. The housing element is accordingly oil-tight and / or waterproof and is made of or with a material that is (at least substantially) transparent to the ambient light and the light of the display unit, as is the case with conventional eyeglass lenses. The micro-mirror elements and the support structure are also advantageously made of a transparent material, as will be explained again below.

[0017] The liquid bath of micro-mirror elements and support structure has a damping effect, suppressing vibrations and thus unwanted small, rapid changes in the angular orientation of the reflecting surfaces. This is advantageous because the eye performs sudden movements of up to 1000° per second and then rests. Furthermore, the liquid reduces a difference in refractive index at the material transition, i.e., the interface between the liquid and the micro-mirror or support structure. This reduces Fresnel reflections on the one hand, and other refractive effects on the other. Both the reduction of reflections and effects reduces the visibility of the elements or structures in the liquid bath, as is known, for example, from glass components immersed in water.This avoids artifacts in the field of view that detract from the user's immersive experience, and makes the use of the micro-mirror element arrangement ("micro-mirror array") directly in front of the user's eyes in their field of view possible in the first place. However, the micro-mirror array enables the large-scale virtual extension of the field of view with greater (angular) resolution for the virtual image and is thus a prerequisite for an immersive glasses display system with dimensions similar to those of commercially available glasses.

[0018] In a further embodiment, it is provided that the micro-mirror elements and / or the support structure and / or further components which are surrounded by the liquid or border the liquid (such as a side of the housing element facing the interior) are each (at least substantially) transparent to the ambient light from the user's field of vision, as also described above for the housing element. The micro-mirror elements and / or the support structure and / or further components are accordingly made from or with a respective transparent material with a first refractive index. In particular, the housing element and / or the micro-mirror elements and / or the support structure and / or the further components can be made from the same material, which facilitates the adaptation of the optical properties to one another.

[0019] The liquid is also (at least essentially) transparent to ambient light and has a second refractive index adapted to the first refractive index in order to ensure the smallest possible deviation. Accordingly, the liquid must be selected such that the second refractive index does not deviate from the first refractive index by more than a predetermined limit value of, for example, 0.005 over a predetermined wavelength range of, for example, 400 nm - 700 nm and / or a predetermined temperature range of, for example, 0° - 30°. The liquid can also be optimized for one or more sub-ranges of the respective ranges, for example, having a second refractive index particularly similar to the first refractive index in the wavelength range of 540 nm + / - 30 nm and / or in the temperature range of 21° + / - 2°.

[0020] In the sub-range, a smaller maximum limit value for the deviation can be specified accordingly, for example 0.002. Such liquids, “refractive index matching liquids,” are commercially available with desired properties. Accordingly, it can be advantageous to actively control the temperature of the micro-mirror array, i.e. to measure it and set a target temperature or target temperature range by heating or cooling. A temperature control device for the liquid can therefore be provided. The temperature control device can have a sensor unit for measuring the temperature of the liquid and a temperature control unit for adjusting the temperature of the liquid to a specified temperature value, i.e. depending on the measured value and the specified temperature, either for heating or cooling. In this way, temperature-dependent deviations can be avoided or at least reduced.

[0021] This means that the ambient light is refracted so little as it passes through the deflection unit that any change in the ambient light, particularly at least in the wavelength range of the ambient light and / or at least in an angular range of the ambient light and / or at least in the temperature range, is below the user's perception threshold. As a result, the material transitions and thus the micro-mirror elements and / or the support structure and / or other components surrounded by the liquid become virtually invisible to the user. Thus, the micro-mirror elements can be arranged over a large area in front of the user's eyes without disrupting their perception of the environment and thus of the virtual image, significantly improving the immersive experience when using the glasses display system.

[0022] In one embodiment, it can be provided that an aperture unit that can be adjusted by means of a control signal is arranged in an optical path of the light between the display unit and the tiltable micro-mirror elements. The adjustable aperture unit is designed to adjust at least one beam position on the deflection unit and / or at least one beam width associated with the respective beam position on the deflection unit for the light deflected at the reflection surfaces of the tiltable micro-mirror elements according to the control signal.The adjustable aperture unit can therefore be used to determine the location of the light hitting the deflection unit via the adjustable beam position and thus the micro-mirror elements the light hits and / or the size of an area on the deflection unit onto which the light hits via the adjustable beam width. This means that certain micro-mirror elements among the micro-mirror elements close to the beam position can be excluded from being illuminated by the light, for example micro-mirror elements which would only be illuminated to a small extent with a larger beam (as explained in more detail below). The adjustable aperture unit can be viewed or referred to as an aperture scanner, since it enables local scanning of the display unit orthe deflection unit, in which an effective aperture (“exit aperture”) is set by the adjustable diaphragm unit and can also be dynamically adjusted with the dynamically adjustable beam width.

[0023] This has the effect that with the control signal and the adjustable aperture unit (which can also be referred to as an adaptive aperture), an exit aperture of the display unit can actually be set dynamically, i.e. in a time-varying manner, by means of a control signal.

[0024] In general (i.e. when viewed without an aperture unit), the exit aperture of the display unit is visible to the eye as a mirror image via each micro-mirror element. If the exit aperture is chosen to be very large, any necessary multiplexing, for example, becomes more complex, and the weight of the AR glasses increases without any added value. When designing the exit aperture (i.e. its diameter), it is therefore desirable to achieve the smallest possible diameter. If the exit aperture of the display unit is too small, a virtual image cannot be projected for every direction the user is looking in. The virtually expandable field of view is therefore relatively small, or a large number of micro-mirror elements would result in gaps in the virtual image because not every (required) virtual pixel would result in a line of sight to a physical pixel.

[0025] The exit aperture of the display unit therefore requires a certain minimum size to enable a light path from the display unit to the micro-mirror element and from the micro-mirror element to the eye for all AR viewing angles, i.e., the largest possible virtually expandable field of view. A pixel image information is thus projected as a beam of rays with the diameter of the display unit's exit aperture onto the deflection unit, onto the micro-mirror elements (the "micro-mirror array" as a whole). A typical diameter of an exit aperture, for example, is 8 mm. A typical diameter for micro-mirror elements or their reflective surfaces is 2-4 mm. Thus, the beam of rays from a pixel image information falls on several neighboring micro-mirror elements simultaneously.Since each micro-mirror element is ideally aligned, depending on the current orientation of the eye, so that the central line of sight from the pupil is projected into the center of the display unit's exit aperture, it can happen that light from a pixel image information incident on two neighboring micro-mirror elements simultaneously can also be seen in the eye simultaneously. However, because neighboring micro-mirror elements are aligned differently, the same pixel image information is perceived from two different reflected directions, resulting in one or more virtual ghost images.

[0026] The adjustable aperture unit ensures that only a cropped beam of rays is projected onto the different micro-mirror elements for each pixel of image information, so that as little light as possible falls on the (nearest) neighboring micro-mirror elements, or only light that does not hit the pupil and is therefore not visible, or only such a small amount of light that this light is not perceived as disturbing.

[0027] It is therefore advantageous to design the adjustable aperture unit in such a way that for each micro-mirror element only viewing directions for the virtual image are provided in which the light striking the respective micro-mirror element occupies a larger area than on other, (nearest) neighboring micro-mirror elements. Extreme viewing directions which primarily (i.e. at least predominantly) strike a neighboring micro-mirror element and in doing so only hit the respective micro-mirror element being viewed (at a particular point in time) to a very small extent, for example just barely grazing it, should accordingly no longer hit the exit aperture of the display unit. Accordingly, a small exit aperture of the display unit can be selected for each micro-mirror element being viewed at a particular point in time, for example as part of a time-multiplexing process, in order to improve the image quality.This is achieved with the adjustable aperture unit. An example of such a case is shown in . Fig. 7f illustrated.

[0028] This has the advantage that diffraction effects during image formation are minimized and maximum sharpness of the virtual image can be achieved. This is because a micro-mirror element, which only deflects a small portion of the total beam originally emitted by the display unit into the eye, acts as an aperture. This means that the beam can be clipped if it is only partially reflected. It is known from optics that if the aperture is selected to be small, diffraction increases. Therefore, it is advantageous to position the beam on the micro-mirror element using the adjustable aperture unit in such a way that it is not, or almost not, clipped by the micro-mirror element. The diffraction effect is shown as an example in Fig. 7c illustrated.

[0029] In another embodiment, it is provided that the adjustable aperture unit is designed to adapt the beam position by adapting at least one position of at least one transparent partial aperture region, i.e. one switched transparent by means of the control signal, within an overall aperture region that can be switched transparent or opaque by the control signal. A remaining region of the overall aperture region that is complementary to the at least one partial region is opaque, i.e. switched opaque by means of the control signal. Thus, one or more partial aperture regions can be switched transparent, so that only these partial aperture regions are permeable to light from one or more pieces of pixel image information assigned to the respective partial aperture region, and other pieces of pixel image information do not reach the deflection unit.As described below, the location of the transparent sub-area(s) can vary over time, for example to implement a time-division multiplexing process. This has the advantage that crosstalk of the pixel image information, which can result in the ghost images mentioned above, for example, is avoided or at least reduced. This improves image quality even for large fields of view and increases the immersion of the system. As explained further below, the terms “transparent sub-area” and “opaque remaining area” can also be understood to mean that in the sub-area and remaining area the light is modified in a way other than absorption, so that light falling on transparent sub-areas is ultimately visible to the user and light falling on opaque remaining areas is ultimately invisible to the user. As explained below, this can occur as an alternative to absorption, for example by changes in the polarization properties of the respective light.

[0030] In a further embodiment, the adjustable aperture unit comprises or is a mechanoelectric aperture element. The mechanoelectric aperture element has an aperture that is displaced in a plane transverse to the optical path of the transmitted light when the beam position is adjusted, for example, by a micro-electro-mechanical mirror ("MEMS mirror"). Alternatively or additionally, also to the embodiments with a pixelated liquid crystal element explained below, the aperture unit can comprise one or more switchable polarization diffraction gratings. When the beam position is adjusted, the transmitted light can be deflected in several different directions depending on an applied voltage.To achieve a lateral shift, an inverse diffraction grating is placed downstream of each diffraction grating, so that the first diffraction grating causes a change in angle, while the second grating compensates for this change. Offsetting these two diffraction gratings in the direction of the optical axis results in a lateral shift of the original aperture on a plane orthogonal to the optical axis. A corresponding technical implementation is published in: Guo, Qi, et al., "Fast switching beam steering based on ferroelectric liquid crystal phase shutter and polarization grating." Liquid Crystals 46.9, (2019): 1383-1388.

[0031] In a further embodiment, it is provided that the adjustable aperture unit is designed to adapt, in addition to the at least one beam position, a beam width assigned to the beam position(s) for the light deflected at the reflection surfaces of the tiltable micro-mirror elements in accordance with the control signal. The beam width can be adapted in particular by adapting an area and / or a diameter of the at least one transparent partial aperture region assigned to the respective beam position within the overall aperture region that can be switched to be transparent (in particular transparent or opaque) by the control signal. The beam width can in particular also be adapted differently for different beam positions. This optimizes the image quality, in particular also for differently sized reflection surfaces of the micro-mirror elements at different beam positions.By depending on the control signal, the beam width can be adjusted (and / or specified) over time and / or for time-varying beam positions. This can improve the performance of a multiplexing process and increase image quality.

[0032] In one embodiment, the beam width of the emitted light in the optical path in front of the adjustable aperture unit is larger than the diameter of the reflecting surface(s) of the illuminated micro-mirror elements. This applies to parallelized light; otherwise, the beam widths at the reflecting surfaces with and without the aperture unit are compared. This allows the effective beam width to be optimized particularly well, since it is particularly easy to specify a beam position with favorable, i.e., large-area irradiation of one or more reflecting surfaces.

[0033] In one embodiment, the adjustable aperture unit is configured to adjust the beam width such that it is smaller than the diameter of the reflective surface(s) of the respective illuminated micro-mirror elements, in particular (in the case of micro-mirror elements with differently sized reflective surfaces) of one of the illuminated micro-mirror elements. This allows the light to be directed from the deflection unit into the eye with particularly few artifacts (e.g., ghost images), which increases image quality and thus immersion of the system.

[0034] In a further embodiment, it is provided that the adjustable aperture unit is designed to adjust the beam position and beam width for the light in such a way that at least (in particular always) a large portion of the light transmitted through the adjustable aperture unit illuminates the reflection surface of exactly one of the micro-mirror elements in the form of exactly one light beam. Alternatively, it can be provided that the transmitted light illuminates several micro-mirror elements in the form of several (in particular disjoint) transmitted light beams, wherein each of the transmitted light beams, with the beam position and beam width predetermined by the adjustable aperture unit, precisely illuminates at least a large portion of the light of the respective light beam. This can be achieved, for example, by simultaneously switching several partial aperture areas of the overall aperture area transparent.A majority can be understood to mean at least 50%, preferably at least 65%, particularly preferably at least 80%. This allows a particularly bright, sharp virtual image to be displayed. In both cases, the display unit can be switched off in certain areas, so that not only is the aperture unit prevented from (already generated, emitted) light from adversely affecting the deflection unit, but this is also achieved through more targeted light emission. On the one hand, this is more energy-efficient, and on the other hand, depending on the geometric interplay of the user's line of sight and the geometry of the AR glasses, beam adjustment via the aperture unit alone or beam adjustment via the aperture unit in combination with beam adjustment via the partially switched off display unit delivers results that lead to better image quality.Area-by-area switching can also be used to create spatially separated virtual pixels at a given time, given a given adjustment or setting of the aperture unit with several spatially separated active physical pixels. Light from different physical pixels then passes through a transparent partial aperture area at a given time, creating virtual pixels at spatially separated locations. Area-by-area switching reduces artifacts and improves image composition.

[0035] In another embodiment, a frame rate is specified for the computer-generated image information; and the aperture unit is designed to adapt (in particular change) the beam width and / or beam position several times within the time period specified for an image according to the frame rate. The beam width and / or beam position are thus adapted / changed at an adaptation frequency (“sub-frame rate”) that is higher than the frame rate, which results from the frame rate times the number of beam positions (which correspond to the scan positions of the exit aperture). The pixel image information of a pixel may then only be displayed in one or a few sub-images within an individual image (“frames”). In order to control the display unit, in addition to the pixel image information, a scan position, i.e.The angular deflection of the corresponding micro-mirror element(s) through which the light is transmitted by the aperture unit at the corresponding times must be known. The angular deflection then determines when the respective pixel image information is displayed, or vice versa, as is known from scanning processes.

[0036] In particular, if the exit aperture of the display unit is larger than the reflection surface of a micro-mirror element, there is more than one scan position for the exit aperture for each frame, at which the light falls on a micro-mirror in such a way that the corresponding pixel image information is visible to the eye only for this spatial direction played on the micro-mirror. Thus, in the form of the aforementioned (sub-frame) time multiplexing, different virtual pixels of the virtual image can be technically realized by the same physical pixel of the display unit. This requires a display unit whose pixels can display several (at least two) pieces of pixel image information in a sub-frame of the individual images in a manner synchronized with the change in the angular orientation of the micro-mirror elements (which function as exit aperture scanners).

[0037] This results in the special technical effect that more virtual pixels are realized than physical pixels are available. For example, if the light is reflected from the side, a field of view of 50° covered by the display unit may be necessary. If this field of view is doubled by the mirrors, then approximately only 50° / 100° = ½ of the virtual pixels are physically required, and all other virtual pixels are realized by time-multiplexing neighboring physical pixels. This has the advantage of allowing the use of a smaller display, enabling further miniaturization of the overall system.

[0038] It can be provided that the aperture unit is configured to adjust the beam position to at least three, in particular at least 7, preferably at least 10, and particularly preferably at least 200, most particularly preferably 400 different beam positions within the time period specified for an image according to the refresh rate. This allows the light to be directed particularly flexibly onto the micromirror elements, so that particularly high image quality can be achieved.

[0039] The aperture unit can be configured to adjust the beam width and / or beam position at a frequency of at least 100 Hz, preferably at least 1000 Hz, particularly preferably at least 20 kHz. A frequency of at least 100 kHz is also possible. µLEDs are particularly suitable for this purpose, as they can be operated at a very high on / off switching frequency (currently up to 300 kHz) and thus achieve high brightness (light intensity).

[0040] Accordingly, a control unit can be provided, which is configured to control the adjustable aperture unit using the control signal and the display unit using a further control signal according to a time-division multiplexing scheme, in which at least two virtual pixels of the virtual image are assigned to a physical pixel of the display unit. Time-division multiplexing thus ensures that light from a physical pixel is directed onto the reflective surfaces of different micro-mirror elements at different times.

[0041] For example, using a GPU as the control unit, an image can be calculated that is to be displayed as a virtual image. Each pixel of the image describes a piece of pixel image information that is to be displayed for a spatial direction in the user's field of view. In the method presented here, however, the mirrors move continuously to direct the light into the viewer's pupil as the orientation of the eye changes. Although the radiation direction of the display unit is constant, the light rays deflected in the deflection unit are observed, and after each movement of a micro-mirror element, a new assignment of physical pixel to virtual pixel in the specified spatial direction must be calculated in order to display the image information in the specified spatial direction. For this purpose, the angular orientation or direction of each micro-mirror element must be known.For this purpose, the individual micro-mirror elements can be equipped with an individual angle sensor for measuring the respective angular orientation, or the micro-mirror elements can be controlled so precisely that the controlled position is known with sufficient accuracy. For example, the corresponding pixel-to-spatial direction assignment rule can be stored in a lookup table for each mirror position. The assignment rule can thus be used to specify an assignment of the respective virtual pixels of the virtual image to a respective physical pixel of the display unit that changes depending on the orientation of the eye. The content of a virtual pixel can thus be specified according to the assignment rule for different orientations of the eye (and thus at different times) by different physical pixels and / or by different micro-mirror elements or their angular orientation.

[0042] In the case of a resulting blending from one micro-mirror element to another, a beam of rays that hits both micro-mirror elements may have a reduced intensity in the eye because not the full area of ​​the beam of rays hits the eye, e.g., if in the limiting case half of the beam of rays hits each micro-mirror element. This is exemplified in Fig. 7c. Compared to a beam path in which the beam hits the micro-mirror element in the center, a reduced intensity is perceived by the viewer's eye in this case. As explained further below, it may be advantageous to increase the physical brightness of the associated physical pixel accordingly in this case, so that the user perceives a homogeneous image brightness.

[0043] In one embodiment, it is provided that the aperture unit comprises or is a pixelated liquid crystal element, in particular with a bistable liquid crystal, which can be divided into individually switchable volumes. One possibility is to arrange the pixelated liquid crystal element (and thus the aperture unit at least partially, i.e. partially or entirely) in the beam path close to the deflection unit, for example by integrating it into the spectacle lens. Another possibility is to arrange the pixelated liquid crystal element (and thus the aperture unit at least partially, i.e. partially or entirely) in the beam path close to the display unit, for example by integrating it into an optic of the display unit or by arranging it on the optic. Arranging in the beam path close to a unit can be understood, for example, as arranging in the 25%, in particular 10%, of the beam path closest to the respective unit.The advantage of the pixelated liquid crystal element is that the beam position and / or beam width can be adjusted very quickly and very precisely, allowing individual micro-mirror elements to be easily "switched on" or "activated," i.e., used to display the virtual image by irradiating the individual micro-mirror element. This allows, for example, time-division multiplexing with good image quality to be realized.

[0044] However, using a simple pixelated liquid crystal element near the deflection unit without any additional elements creates the problem that the AR glasses become opaque to ambient light, since most of the micro-mirror elements are "switched off" at one point in time during time-multiplexing. This results in very low transmission, even at high scanning speeds.

[0045] To avoid this problem, one embodiment provides that the pixelated liquid crystal element is or comprises (in particular only) a switchable wave plate, and the diaphragm unit comprises, in addition to the liquid crystal element, a first and, in particular, also a second static polarization element, which, in the case of two polarization elements, are each transparent to different polarizations. For example, the first polarization element can be transparent to s-polarized light and the second polarization element to p-polarized light, or vice versa, or this can apply analogously to two other, for example, circularly polarized states. The first polarization element is arranged in the optical path between the display element and the pixelated liquid crystal element, preferably on the display unit and / or in the beam path near or in the display unit.The second polarization element is arranged in the optical path between the pixelated liquid crystal element and the micro-mirror elements, preferably at the deflection unit and / or in the beam path near or in the deflection unit.

[0046] If only the first polarization element is present, it is preferably arranged on the deflection unit and / or in the beam path near or in the deflection unit in the optical path between the display element and the pixelated liquid crystal element. The first polarization element can, for example, be transparent to s- or p-polarized light. In this embodiment, the first polarization element is arranged such that light deflected into the eye by the deflection unit also passes through it. In this embodiment, light perceived by the user thus passes through the first polarization element twice with the first but without the second polarization element. The switchable wave plate is then a switchable λ / 4 plate, whereby the light linearly polarized by the first polarization element is converted into circularly polarized light.When reflected at or in the deflection unit, the circular polarization is converted, i.e., clockwise rotating light is converted into counterclockwise rotating light, or vice versa. When the light passes through the switchable wave plate and the first polarization element again, the aperture unit, i.e., the switchable wave plate, can be adjusted to select which lights are transmitted through the aperture unit and which are not. Since the ambient light can be assumed to be unpolarized to a good approximation, the view of the natural surroundings remains unobstructed in this case.

[0047] The adjustable aperture unit is designed to adapt the beam position of the light incident on the micro-mirror elements by adapting the conversion property for polarizations of the total aperture area (formed in particular by the liquid crystal element / wave plate with the second polarization element), either to convert the polarization in the transparent partial area(s) in combination with maintaining the polarization in the remaining area of ​​the total aperture area which is different from the partial area(s), or vice versa.

[0048] For example, in an embodiment with two polarization elements, unpolarized light emitted by the display unit can first be converted into a first polarization, e.g. s-polarization, by the first polarization element. In the at least one transparent partial area of ​​the aperture unit, the polarization is converted, e.g. converted to p-polarization, and retained in the remaining area. In front of the micro-mirror elements, the light of both polarizations strikes the second polarization element, which is only transparent to the light of the second polarization. By selecting the transparent partial aperture area, it is possible to set which micro-mirror elements are irradiated with light and which are not, based on knowledge of a geometric relationship between the display unit, aperture unit, deflection unit and eye position.The transparent partial aperture area is then defined in this case according to the above definition as the aperture area through which light passes (transmits) into the user's eye and is thus visible due to the adjustable properties of the aperture unit in the transparent partial aperture area. The opaque remaining aperture area is then defined in this case according to the above definition as the aperture area through which light passes (transmits) into the user's eye and is thus invisible due to the adjustable properties of the aperture unit in the opaque remaining aperture area.

[0049] The light of the second polarization reflected by the illuminated micro-mirror element is then superimposed with the (typically unpolarized) ambient light and, after passing through the second polarization element and the pixelated liquid crystal element, is beamed into the user's eye. Since the ambient light is also polarized, the AR glasses are darkened, similar to sunglasses, since only one polarization state, i.e., half of the light, can be transmitted by the second polarization element.

[0050] As an alternative to arranging the pixelated liquid crystal element near the deflection unit, one embodiment may provide for the pixelated liquid crystal element to be arranged near the display unit. This places the pixelated liquid crystal element in the beam path between the display unit and the deflection unit, but not in the beam path between the micro-mirror element and the eye. This avoids a dimming effect similar to that of sunglasses, as in the above embodiment.

[0051] In this case, the adjustable aperture unit can be used to scan the exit aperture of the display unit in discrete positions by successively switching different sub-areas of a total aperture area irradiated by the display unit transparent and making the respective remaining areas opaque. The transparent sub-areas can be circular, square, or hexagonal, for example. Transparent sub-areas at successive time steps can overlap. The transparent sub-areas thus form one or more sub-apertures for a given time step.

[0052] As an alternative to the overlapping sub-apertures described in the last paragraph, the sub-areas made transparent in successive time steps can also be selected to be disjoint. The exit aperture of the display unit is thus divided into adjacent areas or sub-apertures for scanning by the micro-mirror elements. This has the advantage that only a few sub-frames have to be displayed by the display unit, i.e. the requirements for the speed of the display unit and the necessary brightness intensity are lower. This takes advantage of the fact that light that falls simultaneously on a micro-mirror element and its nearest neighbor generally does not hit the pupil of the eye in both cases: Since a neighboring micro-mirror element has a different angular position, the light from the neighboring mirror generally hits next to the pupil in this case.The reduced minimum requirements for the display unit also have a positive effect on image quality.

[0053] The electrical structures required to switch the liquid crystal element can lead to diffraction effects in transmission, which can degrade the image. However, these diffraction effects can be influenced by selecting the size of the structures so that the diffraction orders do not reach the eye and are therefore invisible to the user. A particular advantage is that the micro-mirror elements are very small, so even slight angular deviations in the light passing through the aperture unit no longer reach the pupil of the eye.

[0054] In a further embodiment, the spectacle display system comprises an additional focusing unit, in particular with or consisting of an electrically adjustable, fluid-controlled lens, which is arranged in or on the display unit. The focusing unit is designed to shift a focal plane for the light emitted by the display unit according to an additional control signal. The focusing unit can accordingly be referred to as an adaptive focusing unit. The additional focusing unit can be designed, for example, to resolve the vergence accommodation problem and / or to compensate for a visual impairment of the user.

[0055] By choosing an adaptive aperture (in the form of an adjustable diaphragm unit) that is smaller than the pupil of the human eye (i.e., a transparent partial aperture area for the adjustable diaphragm unit that is smaller than the pupil), the depth of field of the projected image is increased. As a result, the virtual image is not only sharp at a defined distance, but over a certain area as perceived by humans. In this way, the image can be displayed sharply at different distances without the need for an additional focusing unit, provided these distances lie within the depth of field, thereby advantageously solving the vergence accommodation problem. The beneficial effect of small effective apertures on depth of field can also be combined with a focusing unit to sharply depict areas larger than the depth of field at different distances in front of the eye.

[0056] Since the adaptive aperture unit and the eye's pupil limit the effective diameter of the optical path of a virtual pixel, the requirements for the projection optics are advantageously reduced. This allows for a large f-number in the projection optics, i.e., a large aperture, while a sharp image only needs to be guaranteed for a small area of ​​the optics. This simplifies the design and manufacture of the projection optics. A larger f-number also enables a shorter focal length and thus the use of a smaller display, which is advantageous for a miniaturized design.

[0057] The additional focusing unit allows the focus of the virtual image to always be adjusted to the position of the current viewing direction. Information on eye orientation (“eye tracking”) can be used for this purpose, as described further below. Preferably, the focus is changed uniformly for the entire virtual image, for example, by using an electrically adjustable liquid lens. However, other optical approaches are also possible, for example, by stacking several transparent displays. Flat reflection surfaces allow any focus distance of the display unit to be displayed without causing aberrations. Other known beam splitter technologies, such as waveguides, in contrast, must be designed for a fixed, predetermined focus distance.

[0058] With the additional focusing unit, especially the fluid-controlled lens, a user's visual impairment can be dynamically compensated (i.e., individually for different users) regardless of the resolution of the vergence accommodation problem. In this case, an additional lens element must be placed in an optical path of the ambient light from the field of vision to the eye, between the environment and the deflection unit. For example, it is conceivable for the user to wear their conventional glasses for visual acuity correction over the AR glasses or use a corresponding attachment. Visual acuity correction can be further refined with additional lens elements between the display unit and the deflection unit.

[0059] If an additional focusing unit is present, it is particularly advantageous if the reflection surfaces are flat. This allows for the greatest possible flexibility and range of applications for the focusing unit. In contrast, concave reflection surfaces enable particularly high light efficiency. With concave reflection surfaces, the light from only one physical pixel of the display unit is imaged onto a respective micromirror, which then redirects it to the location in the user's eye intended for the virtual image. Accordingly, multiplexing is not required in this case. The concave reflection surfaces can also be selected to focus directly on the display unit. This eliminates the need for additional optical elements, but all micromirror elements image the display unit simultaneously.As a result, a multiplexing process must be used to map pixel information (the light from a physical pixel of the display unit) unambiguously in a single viewing direction. Regardless of the flat or concave shape, the reflective surfaces can be of different sizes and / or at least partially overlap. A hexagonal shape is advantageous due to its good surface coverage.

[0060] In one embodiment, the glasses display system comprises an eye tracking device (“eye tracking”) for determining the orientation of the user's eye, as well as a control unit for controlling the deflection unit depending on the result of determining the eye orientation. This allows the light to be directed specifically into the pupil of the eye, increasing light efficiency and avoiding undesirable effects such as “eye glow,” in which third parties see reflections of the deflected light in the user's eye. Due to the improved energy efficiency, the weight of, for example, a battery, as well as the required size of, for example, the display unit, can be reduced, which also leads to improved immersion.

[0061] It can be provided that the control unit is also designed to control the display unit according to an assignment rule stored in the control unit. In this case, the assignment rule can specify an assignment of the respective virtual pixels of the virtual image to a respective physical pixel of the display unit that changes depending on the orientation of the eye. The content of a virtual pixel is thus specified by different physical pixels for different orientations of the eye (and thus at different times). This is because, when the micro-mirror elements move, the assignments of physical pixels of the display unit to virtual pixels of the virtual image are always changed, and in a different way for each pixel combination.This nonlinear change is compensated for by the mapping rule, so that the virtual pixels retain their desired position within the virtual image. This increases image quality and enables particularly large virtual images.

[0062] In a further embodiment, the display unit is configured to adjust the intensity of the light emitted toward the respective beam position for each beam position adjusted by the aperture unit. In particular, this can be done by aligning the light flux of the light arriving at different beam positions, either consecutively or simultaneously. The alignment is to be understood in the context of the virtual image to be displayed. Due to the aligned light flux for the different beam positions, the virtual image should be perceived by the user as having a uniform brightness; however, the virtual image may have brighter and darker image areas.The adjusted intensity serves to homogenize the image brightness in the sense of compensating for light losses caused by the aperture unit in the respective viewing directions and to achieve a two-dimensionally specified light intensity profile for the virtual image.

[0063] The described features and feature combinations, including those in the general introduction, as well as the features and feature combinations disclosed in the description of the figures or the figures alone, can be used not only alone or in the described combination, but also with other features or without some of the disclosed features, without departing from the scope of the invention. Consequently, embodiments that are not explicitly illustrated and described in the figures, but that can be created by separately combining the individual features disclosed in the figures, are also part of the invention. Therefore, embodiments and feature combinations that do not encompass all features of an originally formulated independent claim are also to be considered disclosed.Furthermore, embodiments and combinations of features are to be considered as disclosed which deviate from the combinations of features or go beyond those described in the dependencies of the claims.

[0064] In the context of this disclosure, “transverse / alongitudinal” can be understood as “at least substantially perpendicular / parallel,” i.e., “vertical / parallel” or “substantially perpendicular / parallel,” i.e., perpendicular / parallel except for a predetermined deviation. The predetermined deviation can, for example, be a maximum of 15°, preferably a maximum of 5°, particularly preferably a maximum of 3°. Accordingly, “oppositely oriented” in the context of this disclosure can be understood as “at least substantially oppositely oriented,” i.e., “at least substantially antiparallel oriented.” The restriction “substantially” can also refer to a maximum permissible deviation specified as a percentage, for example a maximum of 15%, preferably a maximum of 5%, particularly preferably a maximum of 3%. Detailed description

[0065] Exemplary embodiments are described in more detail below with reference to schematic drawings. Fig. 1 is a plan view of an exemplary embodiment of a spectacle display system; Fig. 2 a further plan view of the embodiment of Fig. 1 in which an effective pixel multiplication is illustrated; Fig. 3 another plan view of the embodiment of Fig. 1 in which an effective pixel merge is illustrated; Fig. 4 an additional plan view of the embodiment of Fig. 1 in which a combined use of a transparent partial aperture area is illustrated; Fig. 5 a schematic diagram of the effect of finite aperture sizes; Fig. 6 is a plan view of exemplary embodiments of a panel unit; Fig. 7 example illustrations of different beam positions on a micromirror array; Fig. 8 exemplary embodiments with a diaphragm unit arranged on the deflection unit; Fig. 9 is a plan view of an exemplary embodiment of a spectacle display system with additional focusing unit and prescription correction; Fig. 10 shows another embodiment of a spectacle display system in a glare situation; and Fig. 11 a front view and interior view of another exemplary embodiment of a glasses display system.

[0066] In the figures, identical or functionally equivalent features are provided with the same reference numerals.

[0067] Fig. Figure 1 shows a plan view of an exemplary embodiment of a spectacle display system, illustrating one half, i.e., one eye. The system can be expanded accordingly, symmetrically, for two eyes.

[0068] In Fig. 1a shows one half of the spectacle display system 1, for example, the left half from above or the right half from below. Light 163", 161", 162" is emitted by a display unit 14 (here arranged laterally), which in this case is imaged by an optical system 13 such that this light 163", 161", 162" is (partially) reflected by micro-mirror elements such as 12, 12', 12" of a deflection unit 17 and strikes the pupil 11 of the eye 10. The optical system 13 can comprise one or more lenses and / or mirrors and / or other optical components such as one or more aperture units (also adaptive, i.e., adjustable with a control signal). The eye is oriented in a central viewing direction B (here parallel to the y-direction).If the micro-mirror elements 12, 12', 12" (for example, with typical dimensions of approximately 2 mm) are designed to be at least substantially transparent to ambient light, then both a viewing of the natural environment 100 according to light rays such as 161', 162', 163' is possible, and a virtual image with light rays 161", 162", 163" can be superimposed on the light rays 161', 162', 163' of an ambient light. The optics 13 can be designed such that the virtual image can be viewed sharply at a finite or infinite distance. The micro-mirror elements 12, 12', 12" are mounted so that they can be movably tilted, so that their angular orientation can be adjusted in two dimensions.

[0069] In the present example, the micro-mirror elements 12, 12', 12" and a support structure for the micro-mirror elements 12, 12', 12" (not shown for reasons of clarity) are optionally arranged in a sealed housing element 17a filled with a liquid 23. The liquid 23 is selected in such a way that the refractive index between the micro-mirror element material(s) and the liquid is as identical as possible. It is known that glass components become invisible when they are immersed in a liquid that has a nearly identical refractive index. Two effects occur here. Firstly, the Fresnel reflection, which occurs when transitioning from one medium to another with a different refractive index, disappears. Secondly, light rays are not refracted at the material transition.However, even with very small differences, there is still the possibility of partial reflection and total internal reflection if the angles meet the interface very flatly.

[0070] In the present embodiment shown, in conjunction with an exemplary determination of the orientation of the eyes 10 and thus the position of the pupils 11 by means of an eye tracking device 15, it is possible to direct the light 163", 161", 162" of the optics 13 very specifically into the pupil 11 of the eye 10. In the case of an eye movement, for example as in Fig. 1b depicts a lateral eye movement, with a changed position of the pupil 11, the micro-mirror elements 12, 12', 12" are aligned accordingly so that the light 163", 161", 162" of the optics 13 again hits the pupil 11 exactly. In addition to the support structure for the micro-mirror elements 12, 12', 12", the micro-mirror elements 12, 12', 12" are also equipped with one or more actuator elements (not shown for reasons of clarity) for adjusting the angular orientation and thus the respective reflection angles, and in the present case additionally with an individual angle sensor (also not shown here) for measuring the current angular orientation.

[0071] This enables a control loop for tracking the micro-mirror elements 12, 12', 12", so that the light 163", 161", 162" of the optics 13 hits the pupil 11 of the eye 10. For this purpose, the position of the pupil 11 is measured with the eye tracking device 15, and the desired angular orientation of the micro-mirror elements 12, 12', 12" is calculated by a control unit and subsequently compared with the actual position of the micro-mirror elements 12, 12', 12". The actuator element(s) then adjusts the difference between the actual and desired positions, aiming for a sufficiently high speed so that the eye 10 can perceive the virtual image stably even when moving. Speeds of 1000° / s are known as the maximum eye speed, from which a minimum processing speed can be derived.

[0072] When the angular alignment of the micro-mirror elements 12, 12', 12" is changed, the viewing direction also changes with the new orientation of the eye 10, which now deviates from the central viewing direction B. In comparison of Fig. 1a and Fig. 1b it is noticeable that the light 161" in Fig. 1a is reflected as light 161 and in Fig. 1b as light 161b, with the lights 161b and 161 differing in their direction. This results in the assignment of the respective virtual pixels of the virtual image to a respective physical pixel of the display unit 14 changing, and the image information emitted in direction 161" by the display unit 14 must be adapted to the changed angular orientation.

[0073] Thus, in the event of an eye movement, not only the orientation of the micro-mirror elements 12, 12', 12" should be adjusted, but also the pixel light image information generated on the display unit 14. However, since the geometric arrangement of the projector to the micro-mirror is known, the laws of optics can be used to calculate which new image information must be displayed so that the human observer at a given location of the pupil (given "eyebox") has the impression that the virtual image has not shifted, and a corresponding assignment rule can be stored in a control unit of the display unit 14.

[0074] The control of the micro-mirror elements 12, 12', 12" is preferably carried out in such a way that the central viewing beam, i.e. the viewing beam that starts from the center of the pupil and hits the associated micro-mirror element in the center, i.e. for example along light 163b in Fig. 1b is deflected to the center of the optics 13. Since, as explained, a change in the inclination of the micro-mirror elements 12, 12', 12" changes the angle at which a pixel image information is seen by the display unit 14, it may be advantageous not to continuously adjust the micro-mirror elements 12, 12', 12", but rather in steps based on a limit value that specifies how off-center the light 163b may strike the pupil 11 of the eye 10. It is advantageous that the eye makes micro-movements that, as a result, do not need to be corrected. Furthermore, it is advantageous that the micro-mirror elements 12, 12', 12" are embedded in the liquid 23, which has a damping effect and suppresses vibrations (i.e., small, rapid angular movements).

[0075] Furthermore, in the present case, an aperture unit 70 which can be adjusted by means of a control signal is arranged in an optical path of the light between the display unit 14 and the tiltable micro-mirror elements 12, 12', 12" of the deflection unit 17. In the present case, the aperture unit 70 is arranged in the optical path or beam path near the display unit. This dynamically adjustable aperture unit 70 is designed to adjust at least one beam position for the light deflected at the reflection surfaces 25 of the tiltable micro-mirror elements 12, 12', 12" according to the control signal, as can be seen from Fig. 2 is explained in more detail by way of example.

[0076] Fig. 2 shows a further plan view of the embodiment of Fig. 1, which illustrates effective pixel multiplication. The exit aperture 41 of the display unit 14 is defined by the optics 13 used here. The aperture 41 is larger than the micro-mirror elements 12, 12', 12" or their reflective surfaces 25. Thus, the emitted light for a physical pixel 14a of the display unit 14 is a light beam with edge rays 60 that simultaneously impinges on several neighboring micro-mirror elements 12, 12', 12" and possibly others. The light beam thereby forms a pixel image information of the display 14. Since neighboring micro-mirror elements 12, 12', 12" have a different inclination, the image information of the same physical pixel 14a becomes visible in the human eye 10 through multiple light beams 61, 62, and 63. However, this would occur at different ambient positions 100a, 100b, 100c, whereby the image information of pixel 14a would be repeated for different solid angles.This corresponds to artifacts called ghost images.

[0077] Such artifacts can be prevented by the adjustable aperture unit 70, which, as a function of an adjustable aperture arranged downstream in the beam path, adjusts or reduces the beam position of the light beam with the edge rays 60, here also its diameter, so that only one of the micro-mirror elements 12, 12', 12" is illuminated. This can be achieved by switching a partial aperture area 70b ( Fig. 6) within a transparent and / or opaque switchable total aperture area 70a ( Fig. 6) can be realized. The relationship between exit aperture 41, diameter 40 ( Fig. 3) and size of pupil 11 is shown below using Fig. 5 is further explained.

[0078] On the other hand, time multiplexing can also be implemented with the adjustable aperture unit 70, in that different partial aperture areas of the total aperture area can be made transparent at different time steps and the respective remaining areas (which can include the partial aperture areas switched transparent at other time steps) can be switched opaque. Exemplary designs of the aperture unit 70 or the aperture area of ​​the aperture unit 70 are shown in Fig. 6a-6c.

[0079] In both cases, a unique, in particular one-to-one, assignment of pixel image information to a micromirror is established.

[0080] Fig. Figure 3 shows another plan view of the embodiment of Fig. 1, in which an effective pixel merging is illustrated. Alternatively or in addition to the Fig. In addition to the case described in Figure 2, in which different virtual pixels can be generated with one physical pixel, it is also possible to form a virtual pixel with different physical pixels, whereby the different physical pixels and different transparent aperture areas can operate simultaneously or at different times in a time-division multiplexing process. This is described below.

[0081] The aperture unit 70 is adapted or adjusted in this case such that two partial aperture areas 70b, 70bb at the edge of the overall aperture area 70a are transparent, and a central remaining aperture area is opaque. Two different physical pixels of the display unit 14 (not shown) are active, so that a first light 161" (of the first pixel) passes through the aperture unit 70 in a first direction toward the deflection unit 17, and a second light 162" (of the second pixel) passes through the aperture unit 70 in a second direction toward the deflection unit. Since the two pixels are arranged at different locations, the two directions differ.

[0082] To better illustrate the functionality of the aperture unit 70, in addition to the lights or light beams 161", 162" transmitted in the configuration shown, the corresponding full lights or full light beams 161*, 162* are also shown. The full lights or full light beams 161*, 162* correspond to the light generated by the first or second physical pixel, respectively, which is transmitted by the aperture unit 70 when the entire aperture area 70a is completely switched to transparent. These full lights 161*, 162* have a beam width W that corresponds to the aperture of the aperture unit 70. Since this aperture and thus the beam width W is significantly larger than a micro-mirror element 12, 12', the full lights 161*, 162* strike several micro-mirror elements (not shown here) in the plane E.

[0083] By adjusting the position and / or size of the transparent partial aperture area(s) 70b, 70bb, a beam position and / or a beam width w1, w2 of the transparent partial aperture area(s) 70b, 70bb can be specified. This also specifies which micro-mirror elements 12, 12' the corresponding lights 161", 162" impinge on. Together with the respective angular orientation of the micro-mirror elements 12, 12' illuminated by the lights 161", 162", the viewing direction for the corresponding virtual pixel is specified.

[0084] In the example shown, the viewing direction for the virtual pixel at the ambient position 100a runs exactly in the middle between two micro-mirror elements 12, 12'. Both micro-mirror elements 12, 12' are tilted in such a way that the lights or light beams 161, 162 deflected or reflected by them run parallel to each other. Since the two micro-mirror elements 12, 12' are (nearest) neighbors, the lights 161, 162 merge into one another, thus being separated by a distance that is smaller than human resolving power. In the example shown, the resulting combined light beam 161, 162 thus has a beam width w1+w2 which corresponds to the sum of the individual beam widths. However, the beam width w1+w2 can also be smaller or slightly larger.

[0085] By creating a virtual pixel using two physical pixels, the Fig. 7d explains

[0086] In Fig. 4 is an additional plan view of the embodiment of Fig. 1, in which a transparent partial aperture area is used in combination. Shown here are three physical pixels A, B, C of the display unit 14, as examples. Their lights 161", 162", 163" each pass through the identically configured (same) transparent partial aperture area 70b. Since the different physical pixels A, B, C are arranged at different locations, their lights 161", 162", 163" are imaged onto different micro-mirror elements 12, 12', 12", which are arranged remotely from one another here, with the same aperture setting of the aperture unit 70. With a suitable angular alignment of the micro-mirror elements 12, 12', 12", they generate respective virtual pixels. This preferably occurs simultaneously, since this allows the switching frequency of the aperture unit to be reduced in time-multiplexing.The result is that in a time multiplexing with an exemplary number of 100 different aperture settings, i.e. 100 different positions for the shown transparent partial aperture area 70b, 1 / 100 of the physical pixels of the display unit are active for the time of one position of the partial aperture area 70b, similar to a sparsely populated matrix.

[0087] Fig. Figure 5 shows a schematic diagram of the effect of finite aperture sizes. Fig. 1 and Fig. 2, three apertures interact: the diameter of the pupil 11, the diameter 40 of the respective micro-mirror element 12, 12', 12" and the exit aperture of the display unit 14, which is determined by the optics 13. In Fig. 5, the corresponding optical system was drawn with optical axis 42 for clarity, and the deflection was ignored. Depending on the line of sight and the distance between the apertures, different apertures can limit the diameter of the relevant beam of the emitted light. Line of sight 44 at the top of Fig. 5, for example, is a limiting case as the maximum angle that is possible through the pupil 11 when viewing a mirror image with the mirror diameter 40 shown. However, viewing ray 44 does not fall on the aperture 41 of the optics 13 and thus no light can be emitted into this angular range by the display unit 14. Instead, the viewing ray 43 has the maximum possible angle at which light from the aperture of the optics 13 is visible in the eye 10. However, a beam of rays (shown here with parallelized light) is relevant in order to increase the light intensity of the image and minimize diffraction effects. A full beam of rays 45 with edge rays 46 is in the center of Fig. 5. Below in Fig. 5 shows a smaller beam 48 that, at the given angle corresponding to the edge rays 47, is limited by the size of the aperture 41. It is therefore advantageous to select the largest possible aperture 41 for the optics 13, thus opening up many viewing angles with full brightness for the virtual image. However, this conflicts with selecting the smallest possible optics 13 in order to save weight and enable a slim AR glasses design. In this technical conflict, several adjacent micro-mirror elements 12, 12', 12" must be considered to ensure that a large, continuous image, i.e., without gaps due to missing virtual pixels, is visible to the eye 10. In this design, the aperture 41 of the optics is then selected to be as small as possible.

[0088] In Fig. 6 shows a plan view of exemplary embodiments of a panel unit. As in Fig. As shown in Figure 6a, the adjustable aperture unit 70 comprises an electrically adjustable or switchable overall aperture area 70a, which can be used for the purpose of a multiplexing process. For this purpose, the switchable overall aperture area 70a is used as an aperture, here with a diameter of 41. The switchable overall aperture area 70a is switched to transparent in a partial aperture area 70b and opaque in the remaining aperture area 70c. In this case, the size of the transparent partial aperture region 70b is selected such that a diameter of the beam bundle that can transmit through the transparent partial aperture region 70b - and thus the beam width of the light that is deflected at the deflection unit 17 - is less than or equal to the diameter 40 of the reflection surface 25 of a micro-mirror element 12, 12', 12".Since the diameter 41 is larger than diameter 40, there is also a position of the transparent partial aperture area 70b, and thus a beam position for the light deflected at the deflection unit 17, in which the resulting beam bundle only falls on one micro-mirror element 12 and not also partially on one or more adjacent micro-mirror elements 12', 12".

[0089] If it is then additionally as in Fig. 6b, the transparent partial aperture area 70b is gradually shifted as a transmission area, e.g., on a spiral path 72. Then, for each viewing angle given by a physical pixel, a position for the transparent partial aperture area 70b can be found, at which the transmitted light only falls on one micro-mirror element 12 and is thus only deflected by this one micro-mirror element 12. The shifting of the transparent partial aperture area 70b can take place continuously or, as shown here, at discrete positions such as 71, 71', etc. If a light beam only falls on one micro-mirror element 12, then only at one surrounding position 100a ( Fig. 2) and not at further surrounding positions 100b, 100c a virtual image of the corresponding physical pixel.

[0090] In Fig. 6c shows an embodiment of a diaphragm unit with a liquid crystal element as the overall diaphragm region 70a. By means of a plurality of linear electrodes 70d, 70e, 70f, which are arranged one behind the other in the optical path with different orientations, a transparent partial diaphragm region 70b can be freely defined in size and position in the overall diaphragm region 70a. The electrodes define the pixel areas in which a liquid crystal of the liquid crystal element can be switched. In the case shown, with an orientation of the different linear electrodes 70d, 70e, 70f at an angle of 120° to one another, a hexagonal shape of the transparent partial diaphragm region 70b results. This is particularly advantageous with a hexagonal shape of the reflection surfaces 25. In addition, this technical implementation is advantageous because no transistors are required within the overall diaphragm region, as is the case, for example,This is the case with liquid crystal displays, because the electrodes 70d, 70e, 70f run to the edge and can be contacted there.

[0091] As can be seen from the Fig. 5, it may be advantageous to support a maximum beam intensity of 50% of the beam intensity available for each physical pixel for each micro-mirror element 12 (i.e., less than the maximum beam width of the light emitted by the pixel, in particular the parallelized light). This advantage arises when the size of the aperture 41 resulting from this restriction must be designed (cf. Fig. 6). If the aperture 41 is to be designed such that all beam widths or all bundle diameters are supported, then the aperture 41 becomes comparatively large. In this case, diameter 41 would have to be selected so large that even light beam 44 would hit the aperture. If, instead, the restriction is placed on only light bundles with an intensity of up to 50% at the location of the mirror diameter 40, then the diameter 41 can be selected to be significantly smaller. This has a further advantage, since a truncated aperture causes greater diffraction and thus reduces the maximum achievable resolution. The resulting decrease in intensity in the virtual image can be compensated for by increased light emission per area of ​​the display unit. Since the geometric conditions for each pixel are known, corresponding compensation can be carried out, e.g., using a lookup table previously generated by calibration.

[0092] As a starting point for the design of the size of the micro-mirror elements 12, 12'', 12''' or their reflection surfaces 25, the requirement can be chosen that for a given effective exit aperture, at least 50% of the achievable intensity should always be achieved with only one reflection surface 25, if the viewing direction is aligned with the light beam centrally striking the micro-mirror element. It should always be ensured that a gapless virtual image can be generated. A gap can describe not only a missing virtual pixel, but also a virtual pixel with a lower intensity that can no longer be sufficiently compensated by a higher emitted intensity (a virtual pixel whose brightness thus deviates noticeably from a brightness profile given for the virtual image).

[0093] Additional boundary conditions include: - the geometry of the relative arrangement of display unit 14 to deflection unit 17 to eye 10, and / or - the smallest possible exit aperture of the display unit 14, and / or - the smallest possible diffraction effects on the micro-mirror elements 12, 12', 12'' (better for larger reflection surfaces 25), and / or - the relative angular alignment of adjacent micro-mirror elements 12, 12', 12'' (larger differences reduce the number of artifacts such as ghost images when light partially falls on adjacent micro-mirror elements 12, 12', 12''), and / or - the step size of the adjustable aperture unit and thus a spatial distance between successive positions for the transparent partial aperture area(s) 70b in a time-multiplexing / scanning method (with a small step size, a position of the partial aperture area 70b and thus a beam position can always be found at which all light transmitted through the aperture unit 70 falls on only one micro-mirror element 12, 12', 12''), and / or - the maximum switching speed for the entire aperture range 70a of the aperture unit 70 (a refresh rate of 60-120Hz should be achieved).

[0094] Fig. Figure 7 shows exemplary illustrations of different beam positions on a respective micromirror array. In the partial images, the positions of the different relevant apertures 11, 40, 41 are projected onto a projection plane E ( Fig. 3), which essentially runs through the micro-mirror elements 12, 12', 12''. The largest diameter is the projection 70a' of the entire aperture area 70a, the second largest diameter is the projection 11' of the pupil 11 with the central viewing point 11'', and the smallest diameter is the beam position 70b', shown as the projection of the transparent partial aperture area 70b, whose diameter corresponds to the beam diameter of the light transmitted through the aperture unit 70. The projection 11' corresponds to a virtual pixel, and the projections 70a', 70b' each correspond to a physical pixel of the display unit 14. For the projection 70a', it is assumed that the entire aperture area 70a is completely transparent. The partial images show situations corresponding to different virtual pixels, i.e., different viewing directions.

[0095] It should be noted here that beams of light are drawn as circles. Due to the angular constellations, in reality they are often ellipses, although beams of any shape are conceivable depending on the aperture. For the sake of simplicity and clarity, this aspect is ignored in the illustrations, and the functionality is explained using circular geometries.

[0096] Fig. 7a shows a situation in which a virtual pixel is observed which is arranged such that the viewing point 11'' hits the shown micro-mirror element 12 essentially centrally. With a larger transparent partial area 70b (and thus beam position 70b' with a greater beam width), the light transmitted through the aperture unit 70 would not only (essentially) hit the micro-mirror element 12 but also the six neighboring micro-mirror elements 12', 12''. Since the micro-mirror elements 12, 12', 12'' are generally tilted differently, the light deflected by the micro-mirror elements 12, 12', 12'' would be imaged in seven different spatial directions. The adjustable aperture unit 70 determines the position and size of the transparent partial aperture area 70b, i.e.the beam position 70b' and beam direction of the transmitted light are adjusted and reduced in size such that the light is (essentially) only deflected by the central micro-mirror element 12.

[0097] It is also possible for a physical pixel to generate multiple virtual pixels by quickly adjusting the position of the transparent partial aperture area 70b and thus the beam position 70b'. This corresponds to a time-multiplexing method. For example, in the situation shown, the aperture unit 70 could also direct light to the pupil from viewing direction 11** with pupil projection 11* if the angular orientation of the micro-mirror element 12' is suitably adjusted. This is exemplified by Fig. 3 explained above.

[0098] Fig. Figure 7b shows a situation in which the observed virtual pixel corresponds to a viewing point 11'' slightly shifted from the center of the micro-mirror element 12. In the case shown, the beam position 70b' is selected such that the associated light beam is nevertheless (essentially only) reflected into the eye by the central micro-mirror element 12. The beam position is thus shifted relative to the viewing direction 11''.

[0099] With the same viewing direction, as in Fig. 7c, the beam position 70b' can be selected such that light also falls on the adjacent micro-mirror elements 12', 12''. For example, this can be the case if the beam position consists of Fig. 7a relative to the viewing direction 11'' in contrast to Fig. 7b is retained. If such overlaps of the light with different micro-mirror elements 12, 12', 12'' are slight, this may be irrelevant: This is because the neighboring micro-mirror elements 12, 12', 12'' have different orientations and generally correspond to only the light from the central micro-mirror element 12 reaching the eye 11. However, the beam width of the light perceived by the user is not only limited by the adjustable aperture unit ("adaptive aperture"), but is also cut off at the edge of the central micro-mirror element 12, which effectively reduces the aperture. The effective beam width corresponding to the hatched partial area of ​​the beam surface in beam position 70b' is reduced, which, as a reduced aperture, reduces the resolving power. Accordingly, it is usually more advantageous to adjust the beam position relative to the viewing direction 11'', as shown in Fig. 7b is shown.

[0100] However, there are also cases in which this is different. If the transparent partial area 70b and thus its projection 70b' are shifted in discrete steps from position to position, the ideal (for example in Fig. 5b) and thus the ideal beam position can be selected. As a technical compromise, the choice of a beam position with a reduced effective beam width can then be achieved, as in Fig. 5c shown in order to take advantage of the fact that a smaller number of discrete positions of the transparent partial aperture area 70b must be scanned. This smaller number of scan positions has the advantage of a higher achievable brightness for the virtual image, since switching the beam positions 70b' by discretely shifting the partial aperture area 70b requires time during which no light can be transmitted, which reduces the light intensity of the virtual image. However, the brighter the virtual image, the more immersive the perception of the virtual image, since only with a sufficiently bright virtual image can the surroundings be prevented from shining through the image.

[0101] Fig. 7d is accordingly Fig. 3 shows a limiting case in which the viewing direction 11'' and thus the observed virtual pixel lies exactly in the middle between two micro-mirror elements 12, 12'. The observed virtual pixel can thus be assigned to two different physical pixels, since the two micro-mirror elements 12, 12' can have different angular orientations, i.e. can be tilted differently. For each physical pixel, respective projections are shown here: for the first physical pixel, whose light is deflected by the first micro-mirror element 12, the projection / beam position 70a', 70b', and for the second physical pixel, whose light is deflected by the second micro-mirror element 12', the projection / beam position 70a'', 70b''.

[0102] Depending on the requirements, one physical pixel can be used for the virtual pixel in the case shown, or two, or even more physical pixels can be used for the one virtual pixel in order to increase the intensity of this virtual pixel. Fig. 7e shows a case in which the viewing direction 11'' and thus the observed virtual pixel lies exactly in the middle between three micro-mirror elements 12, 12', 12''. Analogous to Fig. 7d, a third physical pixel can thus additionally be used via the beam position 70b'' in the projection 70a'' to increase the brightness of the virtual pixel.

[0103] Fig. 7f shows the beam positions of many physical pixels on a common micro-mirror element 12. The lights of the different pixels all pass through the aperture unit 70 through the same transparent partial aperture area 70b. However, since the light from each physical pixel leaves the display unit 14 at a different angle, the associated beam positions 70b', 70b'', ..70b* on the common micro-mirror element 12 are shifted relative to one another. For improved brightness of the virtual image, it is advantageous to use several physical pixels simultaneously for a (scan) position of the transparent partial aperture area 70b and thus of the aperture unit 70. This is exemplified in Fig. 3. However, only pixels should be used (ie activated or switched on) which fall entirely on a common micro-mirror element 12 or at least as shown in Fig. 7c, overlap so clearly with the common micro-mirror element 12 that they are imaged only as a single virtual pixel in the pupil 11. Alternatively or additionally, physical pixels can be used that are far enough apart from each other not to overlap in the virtual image. This is exemplified in Fig. 4 shown.

[0104] In Fig. 8 shows a further exemplary embodiment with a diaphragm unit arranged on the deflection unit. In contrast to the Fig. 1 and Fig. 2, the aperture unit 70 is here close to or as in Fig. 8b, are arranged in the deflection unit 17. This allows an alternative multiplexing method to be implemented. The multiplexing is essentially carried out near the plane of the micro-mirror elements 12, 12', 12''.

[0105] As in Fig. As shown in Figure 8a, a static first polarizer 90 is inserted into the beam path so that the light striking the micro-mirror elements 12, 12', 12'' is fully polarized. Furthermore, a birefringent pixelated switchable (pixelated) liquid crystal element 91 is used to electrically switchably change the polarization, whereby only two states are relevant. With a further static polarizer 92, the individual segments of the segmented liquid crystal 91 can be switched to change the polarization, individual segments 93, 93', 93'', and other segments 94 to maintain polarization, similar to a liquid crystal screen. Thus, light from the display unit 14 falling through the polarization-changing segments 93, 93', 93'' is ultimately visible to the user, while light from the display unit 14 falling through the polarization-maintaining segments 94 is ultimately invisible to the user.The liquid crystal element 91 with the second polarization element 92 thus defines the transparent partial aperture regions 70b and the opaque remaining aperture regions 70c. The segments 93, 93', 93'', 94 of the liquid crystal element 91 are sized such that light passing through only strikes one micro-mirror element 12, 12', 12''. Depending on the diameter 41 of the exit aperture, several segments such as 93, 93', 93'' can be switched simultaneously to change polarization, thus making the corresponding partial aperture regions 70b transparent. Since only one polarization filter is placed between the eye 10 and the natural environment, the eye 10 can see the natural environment 100 independently of the switching state of the liquid crystal element 91, albeit with a 50% reduced intensity, as is known from sunglasses.Depending on the design of the polarization states (linear or circular), it may be necessary to place a static wave plate between the second polarizer 92 and micro-mirror elements 12, 12', 12'' so that the reflected light can again transmit the polarization filter 92.

[0106] In Fig. This is shown in greater detail in Figure 8b. In the example, the display unit 14 emits light or light beams 161'', 162'', 163'' with s- and p-polarization. In the first polarization unit 90, the light beams 161'', 162'', 163'' are s-polarized. In the transparent partial aperture areas 70b of the aperture unit 70, the polarization of light is changed by the liquid crystal element 92, and in the opaque partial aperture areas 70b of the aperture unit 70, it is maintained.

[0107] In this case, the light beams 161'', 162'' are p-polarized and can thus pass through the aperture unit 70 toward the micro-mirror elements 12, 12'. The still s-polarized light beam 163'', however, is absorbed by the second polarization element 92 and cannot pass through the aperture unit 70. The light beams 161'', 162'' are reflected by the micro-mirror element 12 and are visible to the eye 10 and thus to the user as light beams 161, 162, just like the ambient light or the ambient light beams 100a, 100b.

[0108] Fig. Figure 8c shows an embodiment without the second polarization element 92, in which the aperture unit 70 with the liquid crystal element 91 and the first polarization element 90 is arranged close to, here in the deflection unit 17. The liquid crystal element 91 is designed in this case as a switchable λ / 4 plate and thus reverses the polarization of circularly polarized light.

[0109] Light beams 161'', 162'', which are emitted by the display unit 14 as p+s polarized light, thus first pass through the first polarization element 90 and the liquid crystal element 91 before being deflected by the micro-mirror elements 12, 12'. The light beams 161'', 162'' are initially linearly polarized, here s-polarized, by the first polarization element 90. A light beam 161'', which passes through a transparent partial aperture region 70b, is converted into light with a circular polarization, here I-polarized light. A light beam 162'''', which passes through an opaque residual aperture region 70c, is converted into light with a different circular polarization, here r-polarized light.

[0110] Upon reflection from the micro-mirror elements 12, 12', the circular polarization is reversed. This results in only the light 161" from the display unit 14, which has passed through the transparent partial aperture area 70b, being transmitted through the polarization element 90 and thus being visible. Light 162" that has only passed through the opaque remaining aperture area 70c has the incorrect polarization for the polarization element 90 and is absorbed by it. Light from surrounding positions 100a, 100b is not visibly affected by the liquid crystal element 91; only the overall intensity is reduced by the polarization element 90, similar to sunglasses. Fig. Figure 9 is a plan view of one plane of an exemplary embodiment of a spectacle display system with an additional focusing unit, including vision correction. The additional focusing unit 13'', as adaptive optics, is adjusted in its focus by a control unit 110. For example, the focus of the virtual image can be set either to infinity (beam path / light beam 112) or to finite (beam path / light beam 111). This solves the vergence accommodation problem. If the focus can be adjusted faster than a frame rate, different focal planes can even be set within a virtual image.

[0111] With an additional lens element 13''' between the deflection unit 17 and the surrounding area 100, visual acuity correction can be integrated without major effort. Its properties are then taken into account accordingly by the control unit 110.

[0112] Fig. 10 shows another embodiment of a glasses display system in a glare situation. In this case, another person 143 can look into the display unit 14 with their eyes 10" (the optics 13 is embodied here as part of the display unit 14). Thus, there is a risk that person 143 will be dazzled. Since the glasses display system 1 uses cameras 142, 142', for example, to determine their orientation in space, these cameras 142, 142' and / or other sensors such as the eye tracking device 15 can measure the eye positions 10, 10' of the user. This also allows the calculation of an angular range 145 in which emitted light dazzles the opposite person 143. The control of the display unit 14 can thus be informed that there is a risk of dazzling in the angular range 145 and, for example, no content will be displayed in this area or only with reduced intensity.

[0113] In Fig. 11 shows another exemplary embodiment of a spectacle display system. As can be seen from Fig. As can be seen in Figure 11a, the spectacle display system 1 in this example comprises a deflection unit 17 with a plurality of micro-mirror units 12, 12', 12'', which are arranged over a large area in a field of view corresponding to that of conventional spectacles. Fig. 11b shows an interior view of the deflection unit 17 with the numerous micro-mirror units 12, 12', 12''. Neighboring micro-mirror units 12, 12' are shown here as an example, which partially overlap. In the example shown, the micro-mirror units 12, 12', 12'' are arranged offset in the y-direction and are also of different sizes. Micro-mirror unit 12'' has a larger reflection surface than micro-mirror unit 12', and micro-mirror unit 12' has a larger reflection surface than micro-mirror unit 12.

Claims

[1] Glasses display system (1) for displaying a virtual image in a field of view of a user, with - a display unit (14) for emitting a light (163'', 161'', 162'') as computer-generated image information in an emission direction, wherein a refresh rate is predetermined for the computer-generated image information; - a deflection unit (17) for deflecting the light (163'', 161'', 162'') emitted by the display unit (14) as computer-generated image information into an eye (10) of the user, with a plurality of micro-mirror elements (12, 12', 12'') which can each be tilted in a support structure and which each have a reflection surface (25) for deflecting the light (163'', 161'', 162'') emitted by the display unit (14) as computer-generated image information; characterized by - an aperture unit (70) arranged in an optical path of the light (163'', 161'', 162'') between the display unit (14) and the tiltable micro-mirror elements (12, 12', 12'') and adjustable by means of a control signal, which aperture unit is designed to adapt at least one beam position (70b', 70b'', 70b*) for the light deflected at the reflection surfaces (25) of the tiltable micro-mirror elements (12, 12', 12'') to at least three different beam positions according to the control signal within the time period predetermined for an image according to the refresh rate. [2] Glasses display system (1) according to the preceding claim, characterized by that the adjustable aperture unit (70) is designed to adapt the at least one beam position (70b', 70b'', 70b*) by adapting at least one position of a respective transparent partial aperture area (70b) within an overall aperture area (70a) that can be made transparent by the control signal. [3] Glasses display system (1) according to one of the preceding claims, characterized by in that the adjustable aperture unit (70) is designed to adapt, in addition to the beam position (70b', 70b'', 70b*), a beam width associated with the beam position (70b', 70b'', 70b*) for the light deflected at the reflection surfaces (25) of the tiltable micro-mirror elements (12, 12', 12'') in accordance with the control signal. [4] Glasses display system (1) according to the preceding claim, characterized by that the beam width is to be adjusted by adjusting an area and / or a diameter of the transparent partial aperture area (70b) within the total aperture area (70a) which can be switched to be transparent or opaque by the control signal. [5] Glasses display system (1) according to one of the preceding claims, characterized bythat the beam width of the emitted light (163'', 161'', 162'') in the optical path in front of the adjustable aperture unit (70) is greater than a diameter of the reflection surface (25) or the reflection surfaces (25) of the respective illuminated micro-mirror elements. [6] Glasses display system (1) according to one of the preceding claims, characterized by that the adjustable aperture unit (70) is designed to adjust the beam width such that it is smaller than the diameter (40) of the reflection surface (25) or the reflection surfaces (25) of the respective illuminated micro-mirror elements. [7] Glasses display system (1) according to one of the preceding claims, characterized bythat the adjustable aperture unit (70) is designed to adjust the beam position (70b', 70b'', 70b*) and the beam width for the light in such a way that a large part of the light (163'', 161'', 162'') transmitted through the adjustable aperture unit (70) illuminates the reflection surface (25) of exactly one micro-mirror element (12, 12', 12''), in particular in combination with a region-wise switching off of the display unit. [8] Glasses display system (1) according to one of the preceding claims, characterized by , that -the aperture unit (70) is designed to adjust the beam width and / or beam position (70b', 70b'', 70b*) several times within the time period specified for an image according to the refresh rate. [9] Glasses display system (1) according to the preceding claim, characterized bythat the aperture unit (70) is designed to adapt the beam position (70b', 70b'', 70b*) to at least 7, preferably at least 10 and particularly preferably at least 200 different beam positions within the time period predetermined according to the refresh rate for an image. [10] Glasses display system (1) according to one of the preceding claims, characterized by that the aperture unit (70) is designed to adapt the beam width and / or beam position (70b', 70b'', 70b*) with a frequency of at least 100Hz, preferably at least 1000Hz, particularly preferably at least 20kHz. [11] Glasses display system (1) according to one of the preceding claims, characterized by that the aperture unit (70) comprises or is a pixelated liquid crystal element (91). [12] Glasses display system (1) according to the preceding claim, characterized by , that - the pixelated liquid crystal element (91) is or comprises a switchable wave plate; - the aperture unit (70) comprises, in addition to the liquid crystal element, a first and a second static polarization element (90, 92) which are permeable to different polarizations; wherein - the first polarization element (90) is arranged in the optical path between the display element (14) and the pixelated liquid crystal element (91), preferably on the display unit (14), and the second polarization element (92) is arranged between the pixelated liquid crystal element (91) and the micro-mirror elements (12, 12', 12''), preferably on the deflection unit (17); and - the adjustable aperture unit (70) is designed to adapt the beam position (70b', 70b'', 70b*) by adapting the polarization conversion property of the overall aperture area (70a) either to convert the polarization in the transparent partial area(s) (70b) in combination with maintaining the polarization in the remaining area of ​​the overall aperture area (70a) different from the transparent partial area(s) (70b), or vice versa. [13] Glasses display system (1) according to one of the preceding claims, characterized by - a control unit which is designed to control the adjustable aperture unit (70) by means of the control signal and the display unit (14) with a further control signal according to a time-multiplexing, in which at least two virtual pixels of the virtual image are assigned to one physical pixel of the display unit (14). [14] Glasses display system (1) according to one of the preceding claims, characterized by an additional focusing unit, in particular with or consisting of an electrically adjustable liquid-controlled lens, in or on the display unit (14), which is designed to shift a focal plane for the light emitted by the display unit (14) according to an additional control signal. [15] Glasses display system (1) according to one of the preceding claims, characterized by that the display unit (14) is designed to adapt an intensity of the light emitted towards the respective beam position (70b', 70b'', 70b*) for the beam position (70b', 70b'', 70b*) adjusted by the diaphragm unit (70), in particular in such a way that a light flux of the light reaching different beam positions (70b', 70b'', 70b*) one after the other or simultaneously is equalized.

Images