Phototechnical modules for building facades

Abstract

The subject of the invention is a phototechnical module (100) for building facades, in particular for glazing, which has, for its intended arrangement on the building facade, a front side (10a), a rear side (10b), a top side (10c) and a bottom side (10d), which comprises at least a front base plate (2) and a rear base plate (3), which base plates (2, 3) are made light-transmitting and between which an intermediate chamber is formed, and a number of microsheet elements (1) accommodated in the intermediate chamber, each microsheet element (1) being phototechnical. and a microsheet element (1) having a light-tight sheet section (11) with a light-technical front surface (11a) and / or a light-technical rear surface (11b), each microsheet element (1) being hingedly arranged on a front base plate (2) or on a rear base plate (3) by means of peripheral mounting sections (12) in such a way that each sheet section (11) can be swung from a light-tight closed position towards the upper surface (10c) or towards the lower surface (10d) about a horizontal swing axis into at least one light-transmitting open position.

Description

[Technical Field]

[0001] The present invention relates to a photo-technical module for building facades, in particular for glazing, and to a system for constructing building facades. [Background technology]

[0002] Shutter arrays and mirror arrays, which are constructed from a multitude of actuable microelements in the form of microshutters or micromirrors, belong to the so-called Micro-Opto-Electro-Mechanical Systems (MOEMS: Optical MEMS) and are used in many different applications, for example as projector elements, routers, shutters or apertures in the fields of projection displays, optical information processing, microscopy, lithography, laser structuring, or as sunlight-guiding elements in glazing of buildings, for high-resolution light modulation or light deflection.

[0003] The microelements that make up the array are miniaturized optical elements in the size range of a few square micrometers to square millimeters, whose position and thus their optical function can be controlled by active or passive actuation. The microelements are optionally configured in this case as purely opaque microshutters or as micromirrors with reflective surfaces. Typical thin-film methods are used to manufacture the array, in particular thin-film methods using deposition processes, lithographic and etching steps, and sacrificial layer techniques.

[0004] Optoelectronic modules with micromirrors based on MOEMS are known in the prior art for active light deflection in building facades. For example, US Pat. No. 5,629,493 discloses an array in the form of a micromirror assembly for integration into facades, in which the micromirror elements are arranged in a regular, planar matrix and are individually or collectively driven and controlled by a central control unit via an addressing network. This provides the possibility of active sunlight deflection with high spatial resolution, which allows for tailored and personalized lighting conditions in the rooms located behind the facade. For a detailed description of the production, function, and principle of use of such micromirror arrays, see non-patent document 1.

[0005] Furthermore, Non-Patent Document 2 discloses a MOEMS micromirror array for daylight guiding in building glazing. A module based on this MOEMS micromirror array has a front, a back, a top, and a bottom surface, with respect to the placement of the module on a planned building facade. The back surface of the module should be oriented toward the interior of the building, and the top surface of the module should be oriented upward. The module also includes a front base plate and a back base plate, each of which is optically transparent, and a micromirror is housed in an intermediate chamber between the base plates. In this case, the micromirrors are hingedly arranged on the inner surface of the front base plate so that each micromirror can swing from a light-tight, closed position toward the bottom surface of the module around a horizontal swing axis to at least one light-transmitting, open position. In the closed position, the micromirror abuts the front base plate approximately parallel to the surface and reflects incoming sunlight back to the outside of the building facade. When a large number of micromirrors are moved into their closed position, this results in a large-area mirroring of the building facade, which can lead to characteristic light reflections that can be disruptive to, for example, adjacent road traffic or neighboring buildings. In addition, the rear surface of the mirror element is typically also formed to have a metallic luster, so that, in the closed position of the mirror element, a mirror effect also occurs toward the space behind the glazing. However, the large-area internal mirroring of the glazing can be perceived as unwelcome by people in the space.

[0006] The prior art application of optical technical modules for light deflection to building facades also conflicts with the utilization of the building facade surface for energy capture using the photovoltaic effect, which is nowadays implemented in multiple ways by the integration of large areas of solar modules into building facades, including glazing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] DE 10358967 A1 [Non-patent literature]

[0008] [Non-Patent Document 1] Hillmer et al., Jpn. J. Appl. Phys. 57, 08PA07(2018) [Non-patent document 2] Hillmer et al., Journal of Optical Microsystems 1, 014502(2021) Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is therefore to overcome the aforementioned drawbacks of the prior art and to propose a phototechnical module for building facades, which is particularly suitable for building individualized and needs-adapted systems for constructing building facades. [Means for solving the problem]

[0010] The above problem is solved by an opto-technical module according to claim 1 and a system for constructing a building facade based on this opto-technical module according to claim 12. Advantageous developments of the invention are described in the dependent claims.

[0011] The invention relates to a photo-technical module, which, with respect to its intended placement on a building facade, has a front, a rear, an upper and a lower surface, and which comprises at least: a front base plate and a rear base plate, the base plates being optically transparent and having an intermediate chamber formed therebetween; a plurality of microsheet elements accommodated in the intermediate chamber, each microsheet element having a light-tight sheet section with an optically front surface and / or an optically rear surface, each microsheet element being hingedly arranged on a front base plate or a rear base plate by peripheral attachment sections such that each sheet section can be swung from a light-tight closed position towards the upper or lower surface about a horizontal swing axis to at least one light-transmitting open position; Equipped with This includes the technical idea.

[0012] The core idea of ​​the present invention is that, in addition to the front surface, the rear surface of the sheet section of the microsheet element also has an application-specific optical technical function, and the arrangement of the microsheet element on the front or rear base plate, in combination with the selectable swing direction of the sheet section, allows for various properties regarding the optical deflection of sunlight entering the module, thereby providing a wide variety of configuration possibilities for the optical technical function of the light module according to the present invention. The front surface here refers to the surface that is exposed toward the front of the module in the closed position of the sheet section. When the module is properly placed on the building glazing, in the closed position of the sheet section, the front surface is therefore visible from the outside of the building, and the rear surface is visible from the inside of the corresponding building space. The configuration and arrangement of multiple microsheet elements in one module is preferably uniform in this case. Generally, variations in this regard are also possible within the module.

[0013] The sheet sections preferably have uniformly rectangular contours and dimensions. In principle, more complex contours or size ratios may also be suitable, allowing for substantially complete surface coverage of the base plate oriented plane-parallel to one another. The microsheet element has a layer structure that includes at least one light-opaque layer. In the closed position of all sheet sections, in which they are oriented substantially plane-parallel to the base plate, the module is thus light-opaque, so that, for example, sunlight cannot enter the building interior through the assigned windows. In addition to the light-opaque layer, the microsheet element typically has other layers with other optical properties, in particular to form the optical front and back surfaces of the sheet sections.

[0014] For example, the front and / or rear surface of the sheet section may have a mirror effect for visible light and / or near-infrared (NIR), with the front and / or rear surface being formed as a mirror layer, particularly made of metal. The optical function of the mirrored front or rear surface is primarily to deflect incoming sunlight into the interior of the building, i.e., into the space located behind the corresponding module. Depending on the arrangement of the microsheet elements on the front or rear base plate and the swing direction of the sheet section, either the front or rear surface of the sheet section is used for this purpose. In the case of modules in the prior art (see Non-Patent Document 2 above), the microsheet elements are arranged on the front base plate, and in the closed position, the mirrored front surface of the sheet section is exposed toward the front of the module, which, in actual use on a building facade, can cause undesirable disturbances to surrounding traffic due to strong light reflections. This can be avoided according to the present invention, since the rear surface of the sheet section has the desired mirror effect and the swing is performed from the closed position toward the underside of the module. In such an embodiment, the front side facing traffic in the closed position does not contribute to the deflection of sunlight into the interior of the building and therefore does not need to have a mirror effect, so that unwanted dazzling of traffic does not occur. In particular, it is expedient to selectively provide a mirror effect on the front or rear side of the seat section and assign an optical function different from the mirror effect to the respective other side of the seat section.

[0015] For example, the front and / or rear surfaces of the sheet sections have a scattering effect for visible light, and the front and / or rear surfaces have a particularly targeted surface roughness. A targeted scattering effect occurs when the incident light is diffusely reflected rather than directionally reflected, so that the characteristic mirror effect of microsheet elements does not occur. Such an optical effect of the microsheet elements may be desirable, particularly in the case of strong solar radiation, when the sheet sections are moved to a closed position but a mirror effect that could dazzle, for example, surrounding road traffic, must not occur when observed from the outside. For people inside the building, the matte appearance of the darkened glazing is typically more comfortable than a large-area mirror effect.

[0016] In another embodiment, the front and / or rear surfaces of the sheet sections have an absorption effect for visible light and / or near-infrared light, and the front and / or rear surfaces have a layer system that exhibits, in particular, a photovoltaic effect, and the module is designed for photovoltaic energy harvesting. Preferably, the absorptive photovoltaic layer system is arranged on the front surface of the sheet sections, which is exposed to the outside, i.e., the incoming sunlight, when the sheet sections are closed. This allows, for example, the intense sunlight incident during the daytime, which would be desirable to keep out of the space by closing the microsheet elements, to be effectively utilized for photovoltaic energy harvesting. This allows the module of the present invention to combine the reflective light deflection effect of the rear surface of the sheet sections, for example for interior lighting, with the photovoltaic function of the front surface, while simultaneously avoiding reflections that could disrupt road traffic, thereby overcoming the drawbacks of prior art systems for constructing building facades.

[0017] In another embodiment, the front and / or rear surface of the sheet section is formed with a dielectric coating, in particular, to generate a color impression for a specific application. In this embodiment, the modules can be used as design elements of building facades, i.e., their optical function is to generate a specific color impression for the observer. For example, a number of modules formed differently with respect to color properties can also generate color patterns. Color patterns can also be generated dynamically based on the activatability of the individual microsheet elements. Each surface of the sheet section can be formed as an interference mirror, for example, based on a dielectric single or multiple coating. Alternatively, suitable color pigments or nanoparticles can be applied to the coating. The color impression is generated by interference or absorption of a part of the white solar spectrum.

[0018] In particular, each microsheet element has a layer structure, which comprises at least one compressively stressed layer and one tensilely stressed layer, and along the sheet section of each microsheet element, a compressively stressed compensation layer is arranged on the tensilely stressed layer, and each microsheet element has: a sheet section formed to be globally stress-free and having two substantially plane-parallel surfaces; a peripheral mounting section rigidly disposed on one of the base plates; a hinge section located between the seat section and the mounting section, the hinge section having a curvature in which an internal stress is induced, thereby forming an open position of the microsheet element; The area is divided into the following categories.

[0019] In this case, the microsheet elements are in a maximum open position in the absence of external actuation, and the maximum open position is achieved based on the existing internal stresses due to the curvature of the hinge section between the mounting section, which is form-fitted on the base plate, and the stress-compensated sheet section, e.g., the hinge section has a radius of curvature that is 1 / 100 to 1 / 3 of the length of the longest side of the contour of each microsheet element.

[0020] With further advantages, the oscillation of the seat sections between the closed position and at least one open position can be actuated by an electrostatic action principle, for which the front base plate and / or the rear base plate have an electrically conductive layer and the seat sections each have or form an electrode, such that individual microsheet elements and / or groups of multiple microsheet elements can be actuated by application of a voltage signal between the electrode and the corresponding base plate.

[0021] In particular, each microsheet element has at least one electrically conductive layer, thereby forming an electrode layer, and the corresponding base plate has a layer structure, which includes an optically transparent, electrically conductive base layer and an optically transparent, electrically insulating insulating layer, and the mounting section of each microsheet element is disposed on the insulating layer.

[0022] For example, in its most open position, the sheet sections are oriented substantially perpendicular to the base plate, providing maximum light transmission, and this position is assumed when the microsheet element is not subject to electrostatic forces due to the application of a voltage, so that the hinge sections curl up purely in response to their internal mechanical stresses.

[0023] Between the maximally open and closed positions of the sheet sections, further intermediate positions may be assumed, preferably representing corresponding gray values ​​in terms of transmittance. Starting from the maximally open position of the sheet sections, application of a continuously increasing voltage between the base plate and the electrodes can result in stepless closing of the microsheet elements up to a limit voltage beyond which the microsheet elements are completely closed. This variety of application-specific adjustable opening angles of the sheet sections relative to the base plate can be utilized for targeted light deflection, in particular with mirrored sheet sections.

[0024] When an actuation voltage is applied, electric field lines extend from both the rear and front surfaces of the microsheet element toward the conductive base layer. To prevent the seat sections from tipping over to the wrong side against the elastic restoring force of the hinge sections, the mounting section of each microsheet element, in one advantageous embodiment, includes a dielectric shielding layer. The purpose of this shielding layer is to extend the operable swing range of the seat sections beyond 90°, for example, to 120°. The maximum open position is assumed in the absence of applied voltage and is determined by the degree of curvature of the hinge sections. When the seat sections are swung beyond 90° in the maximum open position toward the closed position in which the seat sections are in plane-parallel contact with the base plate, application of an actuation voltage generates an electrostatic attraction between the base layer of the base plate and the seat sections. This attraction is directed toward swinging the microsheet element further in the open direction, thus acting in the opposite direction to the intended actuation logic. To contribute to reducing the electric field strength and thus the parasitic attraction, a dielectric shielding layer is arranged in the mounting section between the substrate and the sheet section that is swung above the substrate. Furthermore, in embodiments with a layer system that exhibits a photovoltaic effect, the potential relationship can be selected so that the electric field strength at the corresponding surfaces of the sheet section is further weakened by the targeted orientation of the n-type and p-type doped layers. The expansion of the sheet section's sway range that can be achieved by these measures allows, in particular, comprehensive utilization of the optical technical functions of the front and rear surfaces.

[0025] For example, the front and / or rear surface of the sheet section may have a layer system exhibiting the photovoltaic effect on an electrode layer, in particular a pn junction based on an organic or inorganic semiconductor. Compound semiconductors such as CuInGaSe2, CdTe, CdSe, GaAs, or CdInGaSe are suitable materials and can be deposited by thin-film deposition processes. The layer system exhibiting the photovoltaic effect is preferably arranged on the front surface of the sheet section, i.e., facing sunlight in a closed position. In principle, however, the rear surface may also be configured for photovoltaic energy harvesting and absorb indirect sunlight or artificial light used in the assigned space.

[0026] Preferably, the microsheet elements have a rectangular outline with an edge length of 10 micrometers to 2 mm and / or are arranged in a regular matrix of parallel rows and parallel columns, so that the entire microsheet elements, in the closed state, form an approximately complete surface coverage of, in particular, the base plate.

[0027] In an advantageous embodiment, the module of the present invention includes an addressing network consisting of planar lines forming electrical connections between the electrode layer and / or photovoltaic layer of an individual microsheet element or a group of multiple microsheet elements and a peripheral module interface for computer-controlled addressing and activation of the microsheet elements and / or extraction of the voltage generated by the photovoltaic effect. This type of addressing network, including the module interface, allows the use of a remotely located controller for driving and controlling the individual microsheet elements, particularly allowing the integration of multiple modules of the present invention into a system for constructing a building facade using a single central controller for the entire system. Alternatively, the use of multiple distributed controllers may be useful, for example, when the floors of an equipped building are occupied by different households, each of which desires individual system control.

[0028] The present invention also relates to a system for constructing a building facade, in particular a glazing, comprising a plurality of optotechnical modules according to at least one of the aforementioned embodiments of the present invention and at least one control device for actuating the microsheet elements of the modules, electrically connected to the modules, wherein the modules are arranged so that their rear faces face the interior of the building and their upper faces face up. The front faces of the modules are in this case exposed to direct or indirect solar radiation, and the rear faces face the space present behind the glazing when attached to the glazing. It should be noted that the positional reference "up" refers to the Earth's gravitational field, i.e., the upper faces of the modules, when arranged on the intended building facade, have a greater distance from the ground than their respective lower faces.

[0029] The configuration of the modules of the system according to the present invention, in particular with regard to the arrangement of the microsheet elements, the swing direction, and / or the optical effect of the front and rear surfaces of the sheet sections, can be adapted to the optical requirements of the building facade, the building's location, and the orientation of the building facade with respect to its orientation. For example, the modules can have individually different configurations, adapted to the optical requirements of the corresponding section of the building facade. For example, it is possible to provide for a specific section of the building facade to suppress the outwardly directed mirror effect of the modules in the closed position of the microsheet elements, for example, to avoid dazzling surrounding traffic. Or the installation of photovoltaically active modules on the building facade can be limited to facade sections with south-, east-, and west-facing exposure.

[0030] In addition to the deflection of visible sunlight and the utilization of photovoltaics, the system according to the invention is also designed to manipulate radiation from the near-infrared and mid-infrared spectrum, and can thus be used in an appropriate manner for the thermal management of buildings, for example, closed modules can contribute to the retention of heat radiation from the interior of a building at night or in winter, particularly by means of a mirror effect.

[0031] Further features that improve the invention will be explained in detail below with reference to the drawings together with the description of preferred embodiments of the invention. [Brief explanation of the drawings]

[0032] [Figure 1a] 1 is a schematic cross-sectional view of an embodiment of an opto-technical module according to the invention; [Figure 1b] 1 is a schematic cross-sectional view of an embodiment of an opto-technical module according to the invention; [Figure 1c] 1 is a schematic cross-sectional view of an embodiment of an opto-technical module according to the invention; [Figure 1d] 1 is a schematic cross-sectional view of an embodiment of an opto-technical module according to the invention; [Figure 2a] 1 is a schematic cross-sectional view of an embodiment having a layer system exhibiting a photovoltaic effect; [Figure 2b] 1 is a schematic cross-sectional view of an embodiment having a layer system exhibiting a photovoltaic effect; [Figure 2c] 1 is a schematic cross-sectional view of an embodiment having a layer system exhibiting a photovoltaic effect; [Figure 2d] 1 is a schematic cross-sectional view of an embodiment having a layer system exhibiting a photovoltaic effect; [Figure 3] 1 is a schematic cross-sectional partial view of an embodiment having a layer system exhibiting a photovoltaic effect; [Figure 4] FIG. 1 is a schematic cross-sectional partial view demonstrating electrostatic actuation. [Figure 5] 1 is a schematic cross-sectional partial view demonstrating the internal stresses of a microsheet element. [Figure 6]1 is a schematic diagram of an exemplary building facade with a system according to the invention consisting of opto-technical modules; DETAILED DESCRIPTION OF THE INVENTION

[0033] 1a-1d show schematic cross-sectional views of four different embodiments of an optoelectronic module 100 according to the present invention, each comprising a front base plate 2 and a rear base plate 3, and a plurality of microsheet elements 1 housed in an intermediate chamber between the base plates 2, 3. For installation on a planned building facade, particularly for glazing, the module 100 has a front face 10a and a rear face 10b, and an upper face 10c and a lower face 10d. The module 100 is intended to be placed on the building facade with the upper face 10c facing upward and the rear face 10b oriented toward the building interior. The front base plate 2, and typically also the rear base plate 3, are optically transparent in this case.

[0034] Each microsheet element 1 has a planar sheet section 11, a mounting section 12 arranged on the respective base plate 2, 3, and a hinge section 13 located between the sheet section 11 and the mounting section 12. The sheet sections are shown in a partially open position. The swing range is indicated by a dashed arc and is illustratively approximately 120° from the closed position. In this closed position, the sheet section 11 abuts the corresponding base plate 2, 3 in a plane-parallel manner. The swing movement is performed around a horizontal swing axis, which is perpendicular to the plane of the drawing. Alternatively, the swing range may be limited to, for example, approximately 90°, so that maximum transmittance is provided for light impinging perpendicularly on the base plate 2, 3 when the actuation means are in a voltage-free state.

[0035] Actuation of the microsheet element 1, i.e., oscillation of the sheet sections 11, is achieved by applying a voltage between the electrically conductive electrode layer 7 and the respective electrically conductive base layers 21, 31. The base layers 21, 31 are disposed on transparent carriers 20, 30 and are electrically isolated from the microsheet element 1 by insulating layers 22, 32.

[0036] Each sheet section 11 has a mirror layer 4, in particular a metallic mirror layer 4, with a mirror effect for visible light and near-infrared (NIR), and on the opposite side a specially designed surface roughness 5 with a scattering effect for visible light. Depending on the position of the sun and the orientation of the sheet section 11, the mirror layer 4 can effect targeted light deflection into the building space. The high reflectivity for NIR radiation additionally contributes to thermal regulation; for example, room heat radiating through a facade window can be reflected back into the building by a suitably positioned mirror layer 4.

[0037] The four illustrated embodiments differ in terms of the placement of the microsheet element 1 on the front base plate 2 or the rear base plate 3 and the respective swing directions of the sheet sections 11, which can swing from a light-tight closed position towards the upper surface 10c or the lower surface 10d of the respective module 100.

[0038] In FIG. 1a, the microsheet element 1 is arranged on a rear base plate 3. Starting from a light-tight closed position in which each sheet section 11 abuts the rear base plate 3 in a plane-parallel manner, the sheet sections 11 can be swung toward the lower surface 10d. The optically-oriented front surface 11a of each sheet section 11 has a surface roughness 5, and the optically-oriented rear surface 11b is formed as a mirror layer 4, which has a mirror effect for visible light and NIR. In the closed position of the sheet sections 11, sunlight incident through the front base plate 2 is scattered by the front surface 11a, so that no dazzling effect due to specular reflection occurs for an observer on the side of the front base plate 2. In the open position of the sheet sections 11, the incoming sunlight is specularly reflected by the rear surface 11b and transmitted through the rear base plate 3 into the building space located behind it, thereby achieving the desired light deflection effect.

[0039] 1b, the microsheet element 1 is also arranged on the rear base plate 3, but here, starting from the closed position, the swinging of the seat section 11 is performed towards the upper surface 10c. The front surface 11a of the seat section 11, which is oriented towards the front base plate 2 in the closed position, is formed by the mirror layer 4, and the rear surface 11b has a surface roughness 5.

[0040] In the embodiments of Figures 1c and 1d, the microsheet elements 1 are disposed on the front base plate 2 of the module 100, and the oscillation direction of the sheet sections 11 is oriented from the closed position in which the sheet sections 11 are in plane-parallel contact with the front base plate 2 toward the upper surface 10c in the case of Figure 1c and toward the lower surface 10d in the case of Figure 1d. In the embodiment of Figure 1c, the front surface 11a of the sheet section 11 has a surface roughness 5, and the rear surface 11b is formed as a mirror layer 4. In the embodiment of Figure 1d, this relationship is reversed.

[0041] The inventive configurability of the module with regard to the arrangement of the microsheet elements 1 on the front or rear base plates 2, 3 and the oscillating orientation of the sheet sections 11 combined with the allocation of application-specific light-technical functions to the front 11a and rear 11b of the sheet sections 11 provides the module 100 with a high degree of adaptability and individuality in relation to the specific requirements present in each case of the assigned section of the building facade constituted with the module 100.

[0042] 1a-1d is furthermore suitable for achieving color effects, in particular on the scattering surfaces of the sheet section 11. For this purpose, the relevant surfaces may be mixed with color pigments or nanoparticles and / or coated with dielectric interference filters.

[0043] 2a to 2d show schematic cross-sectional views of four alternative embodiments of an opto-technical module 100 according to the invention, in which the microsheet elements 1 each have a combination of a mirror layer 4 and, on the opposite side, a layer system 6 exhibiting a photovoltaic effect. With regard to the arrangement of the microsheet elements 1 on the base plates 2, 3 and the swinging orientation of the sheet sections 11, the same relationships apply as in the previous embodiments of FIGS. 1a to 1d.

[0044] The photovoltaic layer system 6 absorbs visible light, UV radiation and part of the NIR, and the module 100 is thereby configured for photovoltaic energy harvesting. The photovoltaic layer system 6 exemplarily comprises two compound semiconductor layers 61, 62, in particular inorganic II-VI, III-V or III-IV-V compound semiconductors, between which a pn junction is present.

[0045] 2a and 2c are particularly suitable for efficient photovoltaic energy harvesting, in which the photovoltaic layer system 6 is arranged on the front side 11a of the seat section 11, which, in the closed position of the seat section 11, is exposed towards the front base plate 2 and thus towards the incident sunlight. If the photovoltaic layer system 6 is arranged on the rear side 11b of the seat section 11, as in the embodiments of FIGS. 2b and 2d, the module 100 essentially functions as an energy converter for indirect sunlight scattered from the ground and for artificial light incident through the rear base plate 3 from the corresponding building space.

[0046] 3 shows a schematic cross-sectional partial view of a key part of an embodiment of a module 100 according to the invention, which comprises a photovoltaic layer system 6. The illustrated microsheet element 1 has a layer structure comprising the photovoltaic layer system 6 with compound semiconductor layers 61, 62 provided on the front surface 11a, a metallic conductive electrode layer 7, and a mirror layer 4 applied along the sheet section 11 to the rear surface 11b.

[0047] The microsheet element 1 is arranged on a rear base plate 3, which has an optically transparent, electrically conductive base layer 31 and an optically transparent, electrically insulating insulating layer 32. A voltage U is formed at the pn junction of the layer system 6 which exhibits the photovoltaic effect. pv can be taken out between the electrode layer 7 and the top electrode 64 at the attachment section 12 of the microsheet element 1 .

[0048] The electrode layer 7, particularly in the hinge section 13, additionally serves as an electrode for electrostatically actuating the microsheet element 1, for which purpose a voltage U akt can be applied. In the sheet section 11, surface charges can be induced on the mirror layer 4 forming the rear surface 11b and on the semiconductor layer 61 forming the front surface 11a.

[0049] In the state shown in Figure 3, the seat section 11 is in a wide open position, having been swung more than 90° from the closed position. In this state, the operating voltage U act When an electric field is applied, a significant attractive force is generated between the front surface 11 a and the base layer 31, which acts to counteract the attractive force between the electrode layer 7 at the hinge section 13 and the base layer 31. The attractive force between the front surface 11 a and the base layer 31 thereby acts to counteract rocking of the seat section 11 to a closed position, preventing intended actuation. To weaken the electric field between the front surface 11 a and the base layer 31, the mounting section 12 includes a dielectric shielding layer 63, which is made of an insulating material with a high dielectric constant.

[0050] The module 100 in all embodiments preferably comprises an addressing network (not shown) that connects individual microsheet elements 1 or groups of microsheet elements 1 with computer-controlled addressing and actuation of the microsheet elements 1 and / or a voltage U generated by the photovoltaic effect. pv The base plates 21, 31 are provided with an addressing network of electrical lines which form electrical connections between the peripheral module interfaces for the extraction of the electrical signals. The electrical lines are applied, for example as a thin metal film, on the respective base plates or are integrated into the base plates, and in particular the electrically conductive base layers 21, 31 may be microstructured, i.e. divided into sections which can be electrically switched independently of one another.

[0051] Preferably, the microsheet elements 1 in the illustrated embodiment are arranged in a regular matrix of parallel rows and parallel columns, so that the microsheet elements 1 as a whole, in the closed state of the sheet section 11, form an approximately complete surface coverage, in particular of the base plates 2, 3. For this purpose, the microsheet elements 1 preferably have a rectangular contour, the edges of which have a length between 10 micrometers and 2 millimeters.

[0052] 4 shows a schematic cross-sectional partial view of a module 100 according to the present invention demonstrating electrostatic actuation. This illustration includes a single microsheet element 1 housed in an intermediate chamber between a rear base plate 3 and a front base plate 2, and positioned on the front base plate 2. For intended installation on a building facade, the module 100 has a front face 10a and a rear face 10b.

[0053] The microsheet element 1 forms an electrode and has an electrically conductive electrode layer for this purpose. The specific optical technical functions of the front surface 11a and the rear surface 11b of the sheet section 11 are not shown here for clarity. The front base plate 2 has an optically transparent carrier 20, an optically transparent and electrically conductive base layer 21, and an optically transparent and electrically insulating insulating layer 22. The microsheet element 1 is arranged on the insulating layer 22 by means of the attachment section 12 of the microsheet element 1, and the swinging movement of the sheet section 11 is achieved via the bending of the hinge section 13 of the microsheet element 1. In the state shown in FIG. 4, an operating voltage U is applied between the microsheet element 1 and the base layer 21. act is applied, so that the electrostatic attraction between the substrate 21 and the microsheet element 1 causes the sheet section 11 to close into the horizontal, or closed, position shown. Shown in dashed lines are two open positions of the sheet section 11: a position oriented approximately perpendicular to the base plates 2, 3, corresponding to maximum transmission of the module 100 at normal light incidence, and a half-open, intermediate position, in which an angle of approximately 45° exists between the sheet section 11 and the base plates 2, 3. The maximum open position is assumed when the microsheet element 1 and the substrate 21 are at the same potential; the partially open intermediate position requires a lower actuation voltage U compared to the closed position. act The applied operating voltage U act By suitably changing the angle .theta., a number of partially open intermediate positions can therefore be adjusted in which the seat section 11 has different angles relative to the base plates 2, 3.

[0054] FIG. 5 shows a schematic cross-sectional partial view of a module according to the present invention, demonstrating the internal stresses of the microsheet element 1. For clarity, the optical function of the microsheet element 1 is again not shown. The microsheet element 1 has a compressively stressed layer 1a and a tensilely stressed layer 1b arranged on a base plate 2. These internal stresses result in the illustrated curvature of the microsheet element 1 along the hinge section 13, here illustratively with a wrap angle of approximately 90°. Along the mounting section 12, this curvature is prevented by a form-fitting connection to the base plate 2, and along the sheet section 11, a compressively stressed compensating layer 1c ensures that the global, i.e., effective, internal stress in the sheet section 11 disappears, thereby preventing curvature. The illustrated layers 1a, 1b, and 1c may, for example, form electrode layers of the microsheet element 1 in their entirety, with the optical function of the microsheet element 1 being generated by stress-free layers or layer systems applied on both sides of the electrode layers.

[0055] In particular, when using vapor deposition methods (PVD, CVD), stresses are usually generated in all layers, i.e., in the layer system exhibiting a photovoltaic effect, in the color layer, or in the matte layer having a scattering effect. In this case, the entire layer sequence is purposefully designed to compensate for the mechanical stresses in the planar sheet section 11.

[0056] In principle, two distinct layers are already sufficient for global stress compensation within the sheet section 11. However, in terms of the design freedom regarding the functionality and dimensions of the microsheet element, it is advantageous to use more than two layers. In the embodiments of Figures 1a-1d and 2a-2d, the microsheet element 1 is formed from three or four layers, although a larger number of layers may be expedient or necessary depending on the intended opto-technical or micromechanical functionality.

[0057] FIG. 6 shows a schematic diagram of a building facade equipped with a system 200 according to the present invention, consisting of phototechnical modules 100. The modules 100 completely encase the building facade, exemplarily here, with the rear surfaces 10b of the modules 100 oriented toward the interior of the building, i.e., the front surfaces 10a are exposed to the exterior, and the top surfaces 10c of the modules 100 are oriented upward. The orientation of the surfaces 10a-10d is shown representatively for two modules 100. The configuration of the modules 100, with respect to the arrangement of the respective microsheet elements and the swing direction and the phototechnical function of the front and rear surfaces of the corresponding sheet sections, is adapted to the phototechnical requirements of each section of the building facade. The various fill patterns of the modules 100 used for illustration purposes indicate the respective module configurations but do not indicate the specific operating conditions, i.e., the orientation of the sheet sections of the microsheet elements. The orientation consistent with this embodiment is indicated by a schematic north arrow.

[0058] The southern facade is subject to the most intense solar incidence, and so the capabilities of the modules 100 for energy capture using the photovoltaic effect can be particularly effectively utilized here. In addition, in configuring the system 200, it should be noted that the southern facade is oriented facing the adjacent road, so that traffic dazzling due to the mirror effect from the modules 100 or "flashing" into vehicles from above or the sides must be avoided.

[0059] The module 100.1, which is mounted on the upper floor of the south facade, comprises a layer system exhibiting a photovoltaic effect on the front side of the sheet section of the microsheet elements, and a mirror effect on the rear side. For example, module 100.1 corresponds to the embodiment shown in FIG. 2a, in which the microsheet elements are arranged on a base plate on the rear side and the sheet section swings from the closed position towards the lower side 10d. The photovoltaic layer system acts to absorb light, so that dazzling mirror effect does not occur to passersby, especially road traffic. The sheet section of module 100.1 is illustratively in a partially open position, so that the light deflection of the incident sunlight is achieved into the space present behind the facade.

[0060] In particular, the operation of the microsheet elements, i.e., the position of the seating sections, is typically adapted to the position of the sun and the needs of the users throughout the day, typically continuously. For example, during the daytime, a fully closed or partially closed position may be adopted, thereby completely or nearly shading the interior space while simultaneously providing efficient solar exposure to the photovoltaic-active front surfaces of the seating sections. The fully closed position typically does not correspond to the optimum conditions for photovoltaic energy capture, since the angle of incidence of the sun's rays relative to the front surface of the module may significantly deviate from 90°. However, a partially open position of the seating section, which forms a 90° angle with the incoming sun's rays, is also not necessarily optimal, since in this case adjacent microsheet elements may shield each other. Rather, the optimum for maximum photovoltaic efficiency lies between the aforementioned positions, and the operation of the microsheet elements can be preferably controlled by a control device, preferably in an open-loop and / or closed-loop manner, so that available sunlight is always optimally utilized throughout the day.

[0061] Module 100.2 comprises a layer system exhibiting a photovoltaic effect on the front surface of the seating section of the microsheet element, and a scattering effect on the rear surface. For example, the microsheet element is arranged on a front base plate, and the seating section swings from the closed position toward the underside 10d of module 100.2. In the closed position of the seating section, the scattering effect on the rear surface creates a matte visual impression for an observer in the corresponding space; that is, unlike module 100.1, there is no large-area mirror effect here, which may be considered inappropriate in certain spaces, especially in public areas. Alternatively, an inward-facing mirror effect may be desired, such as in a restaurant's hall of mirrors, which can achieve the impression of an enlarged room and better lighting.

[0062] Module 100.3, mounted on the east facade, provides a mirror effect on the front surface of the sheet section of the microsheet element and a scattering effect on the rear surface. Module 100.3 corresponds, for example, to the embodiment shown in FIG. 1d, in which the microsheet element is mounted on a base plate on the facade and the sheet section swings from the closed position toward the lower surface 10d. Because the sun is only low in the east, the mirror effect of the sheet section in the closed position would not cause any adverse effects on traffic due to light reflection. Module 100.3 generates targeted light deflection into the building's interior without creating a mirror effect when viewed from inside the building.

[0063] The modules 100.4 and 100.5, which are mounted in the lowest level of the building facade, generate application-specific color impressions through the front surfaces of the sheet sections of microsheet elements, while their rear surfaces have a mirror effect. The color impression from the front surfaces is based, for example, on dielectric coatings or color pigments. The color-influencing modules 100.4 and 100.5 thus perform a particular design function. For example, different color impressions or color patterns, especially lettering or logos, can be generated on each front surface of the building facade.

[0064] The western façade is also equipped in some sections with modules 100.2 for photovoltaic energy harvesting, i.e. modules 100.2 with a photovoltaic layer system on the front and a matte rear surface of sheet sections made of microsheet elements. In the space shown on the top right, where a sleeping person is present, all modules 100.2 as well as the sheet sections of modules 100.3 and 100.6 on the northern façade are in a closed position, so that the room is darkened.

[0065] The north façade is irradiated by indirect sunlight, which is diffused and scattered, especially by clouds or the ground (e.g., also by snow). Even for this indirect light, application-specific light deflection and / or photovoltaics can be beneficial. Here, by way of example, only light deflection is provided for by module 100.3, which corresponds to the embodiment of FIG. 1d, and module 100.6. Module 100.6 is equipped with microsheet elements with sheet sections that have a mirror effect on both the front and rear sides. In addition to the light deflection effect for light entering from the outside, module 100.6, in the closed position, can thus provide a large mirror for the user, if required. In particular, module 100.6 can be designed to operate separately for this purpose, i.e., independently of the remaining modules.

[0066] The main application of the system 200 according to the invention relates to energy savings and thermal management in buildings: by configuring a building facade with the phototechnical module 100 according to the invention, it is possible to significantly reduce the temperature rise in rooms in summer, while in winter it is possible to capture as much of the valuable solar energy as possible, including thermal radiation.

[0067] The present invention is not limited to the preferred embodiment described above in terms of its implementation, but rather many variations are possible using the solutions described, even in radically different implementations. All features and / or advantages that can be seen from the claims, the description or the drawings, including structural details or spatial arrangements, may be used alone or in different combinations. The present application relates to the invention described in the claims, but also includes the following as other aspects. 1. A phototechnical module (100) for a building facade, in particular for glazing, comprising: The module (100) has a front (10a), a rear (10b), a top (10c) and a bottom (10d) surface for placement on the intended building facade; The module (100) comprises at least: a front base plate (2) and a rear base plate (3), the base plates (2, 3) being formed to be light-transmitting, and an intermediate chamber being formed between the base plates (2, 3); a plurality of microsheet elements (1) accommodated in the intermediate chamber, each microsheet element (1) having a light-tight sheet section (11) with an optically technical front surface (11a) and / or a light-tight rear surface (11b), each microsheet element (1) being hingedly arranged on the front base plate (2) or the rear base plate (3) by peripheral mounting sections (12) so that each sheet section (11) can swing from a light-tight closed position towards the upper surface (10c) or the lower surface (10d) about a horizontal swing axis to at least one light-transmitting open position; Equipped with Photo-technical module (100) for building facades, in particular for glazing. 2. The module (100) according to claim 1, characterized in that the front surface (11a) and / or the rear surface (11b) of the sheet section (11) have a mirror effect for visible light and / or near-infrared light, and the front surface (11a) and / or the rear surface (11b) are formed as a mirror layer (4), in particular made of metal. 3. 1 or 2. The module (100) according to claim 1 or 2, characterized in that the front surface (11a) and / or the rear surface (11b) of the sheet section (11) has a scattering effect for visible light, and the front surface (11a) and / or the rear surface (11b) have a particularly suitable surface roughness (5). 4. 4. The module (100) according to any one of claims 1 to 3, characterized in that the front surface (11a) and / or the rear surface (11b) of the sheet section (11) has an absorption effect for visible light and / or near infrared light, the front surface (11a) and / or the rear surface (11b) has a layer system (6) that exhibits, in particular, a photovoltaic effect, and the module (100) is formed for energy harvesting, in particular by means of the photovoltaic effect. 5. 5. The module (100) according to any one of claims 1 to 4, characterized in that the front surface (11a) and / or the rear surface (11b) of the seat section (11) are formed, in particular with a dielectric coating or color pigments, in order to generate a color impression for a specific application. 6. Each of the microsheet elements (1) has a layer structure, which comprises at least one compressively stressed layer (1a) and one tensilely stressed layer (1b), and along the sheet section (11) of each microsheet element (1), a compressively stressed compensation layer (1c) is arranged on the tensilely stressed layer (1b), and each microsheet element (1) comprises: a sheet section (11) formed to be globally stress-free and having two substantially plane-parallel surfaces; the peripheral mounting section (12) rigidly disposed on one of the base plates (2, 3); a hinge section (13) located between the seat section (11) and the mounting section (12), having a curvature in which internal stress is induced, thereby forming an open position of the microsheet element (1); It has been divided into 6. The module (100) according to any one of 1 to 5 above. 7. 7. The module (100) according to any one of claims 1 to 6, characterized in that the oscillation of the seat section (11) between the closed position and at least one of the open positions can be actuated by an electrostatic action principle, and for this purpose the front base plate (2) and / or the rear base plate (3) have an electrically conductive layer, and the seat section (11) each has or forms an electrode, and by applying a voltage signal between the electrode and the corresponding base plate (2, 3), individual microsheet elements (1) and / or groups of multiple microsheet elements (1) can be actuated. 8. 8. The module (100) according to any one of claims 1 to 7, characterized in that each microsheet element (1) has at least one electrically conductive layer, thereby forming an electrode layer (7), and the corresponding base plate (2, 3) has a layer structure, which comprises an electrically conductive base layer (21, 31), in particular light-transmitting, and an electrically insulating insulating layer (22, 32), in particular light-transmitting, and the mounting section (12) of each microsheet element (1) is arranged on the insulating layer (22, 32). 9. 9. The module (100) of any one of 1 to 8 above, wherein the mounting section (12) of each microsheet element (1) has a dielectric shielding layer (63). 10. 10. A module (100) according to any one of claims 1 to 9, characterized in that the front (11a) and / or the rear (11b) of the sheet section (11) has a layer system (6) exhibiting a photovoltaic effect on the electrode layer (7), in particular a pn junction based on organic or inorganic semiconductors (61, 62). 11. 11. The module (100) according to any one of claims 1 to 10, characterized in that the microsheet elements (1) have a rectangular contour with an edge length of 10 micrometers to 2 millimeters and / or are arranged in a regular matrix form consisting of parallel rows and parallel columns, and the entire body of the microsheet elements (1) forms, in the closed state, an almost complete surface coverage, in particular of the base plate (2, 3). 12. 12. The module (100) according to any one of claims 1 to 11, characterized in that the module (100) comprises an addressing network consisting of electrical lines forming electrical connections between individual microsheet elements (1) or groups of multiple microsheet elements (1) and a peripheral module interface for computer-controlled addressing and actuation of the microsheet elements (1) and / or extraction of the voltage generated by the photovoltaic effect. 13. A system (200) for constructing a building facade, in particular a glazing, comprising at least: A plurality of opto-technical modules (100) according to any one of 1 to 12 above; At least one control device electrically connected to the module (100) for actuation of the microsheet elements (1) of the module (100); Equipped with With respect to the arrangement of the modules (100), the rear surface (10b) of the modules (100) is oriented toward the interior of the building, and the top surface (10c) of the modules (100) is oriented upward. A system (200) for constructing building facades, particularly glazing. 14. The system (200) according to claim 13, characterized in that the configuration of the module (100) with regard to the arrangement, swing direction of the microsheet elements (1) and / or the optical-technical function of the front (11a) and rear (11b) faces of the sheet section (11) is adapted to the optical-technical requirements of the building facade. 15. 15. A system (200) according to claim 13 or 14, characterized in that the modules (100) each have different settings and are adapted to the light-technical requirements of the corresponding section of the building facade. [Explanation of symbols]

[0068] 100 Optical Technical Modules 200 Systems for constructing building facades 10a front 10b back 10c top surface 10d bottom surface 1 Microsheet element 1a Layer where compressive stress acts 1b Layer where tensile stress acts 1c compensation layer 11 Seat Section 11a Front 11b Rear 12 Mounting Section 13 Hinge Section 2 Front base plate 3 Rear base plate 20,30 Carrier 21,31 base layer 22,32 Insulating layer 4 Mirror Layer 5. Surface roughness 6 Layer systems that exhibit photovoltaic effects 61,62 Compound semiconductors 63 Shielding layer 64 electrodes 7 Electrode layer U pv Photovoltaic voltage U act Operating voltage

Claims

1. A photo-technical module (100) for a building facade, in particular for glazing, said module (100) having, with respect to its intended placement on the building facade, a front (10a), a rear (10b), a top (10c) and a bottom (10d) surface, The module (100) comprises at least: a front base plate (2) and a rear base plate (3), the base plates (2, 3) being optically transparent and having an intermediate chamber formed between the base plates (2, 3); a plurality of microsheet elements (1) accommodated in the intermediate chamber, each microsheet element (1) having a light-tight sheet section (11) with an optically front surface (11a) and an optically rear surface (11b), and each microsheet element (1) is hingedly arranged on the front base plate (2) or the rear base plate (3) by means of peripheral mounting sections (12) so that each sheet section (11) can swing around a horizontal swing axis from a light-tight closed position in which the sheet section (11) abuts the base plate (2, 3) in a plane-parallel manner to at least one light-transmitting open position towards the upper surface (10c) or the lower surface (10d); Equipped with one of the front (11a) and rear (11b) surfaces of the seat section (11) has a mirror effect for visible light and / or near-infrared light, and the other has an optical-technical function different from the mirror effect, Photo-technical module (100) for building facades, in particular for glazing.

2. 2. The module (100) according to claim 1, characterized in that the front face (11a) or the rear face (11b) of the seat section (11) is formed as a mirror layer (4) made of metal.

3. 2. The module (100) according to claim 1, characterized in that the front surface (11a) or the rear surface (11b) of the sheet section (11) has a scattering effect for visible light, and the front surface (11a) or the rear surface (11b) has a particularly suitable surface roughness (5).

4. 3. The module (100) according to claim 2, characterized in that the front (11a) or the rear (11b) of the sheet section (11) has a scattering effect for visible light, and the front (11a) or the rear (11b) has a particularly suitable surface roughness (5).

5. 2. The module (100) according to claim 1, characterized in that the front (11a) or the rear (11b) of the sheet section (11) has an absorption effect for visible light and / or near infrared light, the front (11a) or the rear (11b) has a layer system (6) that exhibits, in particular, a photovoltaic effect, and the module (100) is formed for energy harvesting, in particular by means of the photovoltaic effect.

6. 3. The module (100) according to claim 2, characterized in that the front (11a) or the rear (11b) of the sheet section (11) has an absorption effect for visible light and / or near infrared light, the front (11a) or the rear (11b) has a layer system (6) that exhibits, in particular, a photovoltaic effect, and the module (100) is formed for energy harvesting, in particular by means of the photovoltaic effect.

7. 2. The module (100) according to claim 1, characterized in that the front face (11a) or the rear face (11b) of the seat section (11) is formed, in particular by a dielectric coating or a color pigment, in order to generate a color impression for a specific application.

8. 3. The module (100) according to claim 2, characterized in that the front face (11a) or the rear face (11b) of the seat section (11) is formed, in particular by a dielectric coating or a color pigment, in order to generate a color impression for a specific application.

9. The microsheet elements (1) each have a layer structure comprising at least one compressively stressed layer (1a) and one tensilely stressed layer (1b), and along the sheet section (11) of each microsheet element (1) a compressively stressed compensation layer (1c) is arranged on the tensilely stressed layer (1b), and each microsheet element (1) comprises: a sheet section (11) formed to be globally stress-free and having two substantially plane-parallel surfaces; the peripheral mounting section (12) rigidly disposed on one of the base plates (2, 3); a hinge section (13) located between the seat section (11) and the mounting section (12), having a curvature in which internal stresses are induced, thereby forming an open position of the microsheet element (1); It has been divided into The module (100) of claim 1, characterized in that:

10. 2. The module (100) according to claim 1, characterized in that the oscillation of the seat section (11) between the closed position and at least one of the open positions can be actuated by an electrostatic action principle, for which the front base plate (2) and / or the rear base plate (3) have an electrically conductive layer and the seat section (11) each has or forms an electrode, so that individual microsheet elements (1) and / or groups of multiple microsheet elements (1) can be actuated by applying a voltage signal between the electrode and the corresponding base plate (2, 3).

11. 2. A module (100) according to claim 1, characterized in that each microsheet element (1) has at least one electrically conductive layer, by which an electrode layer (7) is formed, and the corresponding base plate (2, 3) has a layer structure, which comprises an electrically conductive, in particular light-transmitting, base layer (21, 31) and an electrically insulating, in particular light-transmitting, insulating layer (22, 32), and the mounting section (12) of each microsheet element (1) is arranged on the insulating layer (22, 32).

12. 2. A module (100) according to claim 1, characterized in that the mounting section (12) of each microsheet element (1) comprises a dielectric shielding layer (63).

13. 12. The module (100) according to claim 11, characterized in that the front (11a) or the rear (11b) of the sheet section (11) has a layer system (6) exhibiting a photovoltaic effect on the electrode layer (7), in particular a pn junction based on organic or inorganic semiconductors (61, 62).

14. 2. The module (100) according to claim 1, characterized in that the microsheet elements (1) have a rectangular contour with an edge length of 10 micrometers to 2 millimeters and / or are arranged in a regular matrix of parallel rows and parallel columns, so that the entire microsheet elements (1) form, in the closed state, an almost complete surface coverage, in particular of the base plate (2, 3).

15. 2. The module (100) according to claim 1, characterized in that it comprises an addressing network consisting of electrical lines forming electrical connections between individual microsheet elements (1) or groups of multiple microsheet elements (1) and a peripheral module interface for computer-controlled addressing and actuation of the microsheet elements (1) and / or extraction of the voltage generated by the photovoltaic effect.

16. A system (200) for constructing a building facade, in particular a glazing, comprising at least: A plurality of opto-technical modules (100) according to any one of claims 1 to 15, and at least one control device for the actuation of the microsheet elements (1) of the modules (100), electrically connected to the modules (100). Equipped with With respect to the arrangement of the modules (100), the rear surface (10b) of the modules (100) is oriented toward the interior of the building, and the top surface (10c) of the modules (100) is oriented upward. A system (200) for constructing a building facade, in particular a glazing.

17. The system (200) described in claim 16, characterized in that the configuration of the module (100) regarding the arrangement, swing direction and / or the optical technical function of the front (11a) and rear (11b) of the sheet section (11) of the microsheet elements (1) is adapted to the optical technical requirements of the building facade.

18. 17. The system (200) according to claim 16, characterized in that the modules (100) each have different settings individually, and the modules (100) are adapted to the light-technical requirements of the corresponding section of the building facade.

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