SUN PROTECTION DEVICE

Description

State of the art

[0001] The invention relates to a sun protection device, in particular sunglasses.

[0002] From EP 3 223 067 a pair of sunglasses is already known, comprising at least one optical sun protection filter which has at least one liquid crystal cell.

[0003] Furthermore, from US 2018 / 107025 A1, a sun protection device is already known with at least one optical sun protection filter which has at least one liquid crystal cell, with a sensor unit (18a; 18b) which is provided at least for detecting solar radiation, and with at least one control and / or regulating unit which is provided at least for controlling and / or regulating a transmittance of the liquid crystal cell depending on solar radiation, wherein the optical sun protection filter has at least one photochromic protective element whose transmittance changes in particular at least depending on the solar radiation.

[0004] Furthermore, sun protection devices are also already known from US 5 608 567 A and US 2018 / 210233 A1.

[0005] The object of the invention is, in particular, to provide a generic device with improved properties in terms of comfort and usability. This object is achieved according to the invention by the features of patent claim 1, while advantageous embodiments and further developments of the invention can be found in the subclaims. Advantages of the invention

[0006] The invention relates to a sun protection device, in particular sunglasses, with at least one optical sun protection filter which has at least one liquid crystal cell.

[0007] It is proposed that the optical sun protection filter comprise at least one photochromic protective element whose transmittance changes, in particular, at least as a function of solar radiation. This can advantageously ensure a high degree of adaptability of a sun protection device to solar radiation. Protection against solar radiation can advantageously be ensured particularly easily. Advantageously, a particularly high level of comfort for a user of the sun protection device can be realized.

[0008] The photochromic protective element is preferably transparent. A "photochromic protective element" is understood to mean, in particular, a photochromic lens, a photochromic layer, or the like. This is preferably understood to mean an element whose transmittance depends on the incidence of light, in particular solar radiation. The photochromic protective element is preferably designed to darken, in particular automatically, with increasing incidence of light, in particular increasing solar radiation, so that, in particular, the transmittance of the photochromic protective element is reduced.Particularly preferably, the photochromic protective element is designed to brighten, preferably automatically, with incident light, in particular incident sunlight, falling on the photochromic protective element, so that, in particular, the transmittance of the photochromic protective element is increased. In particular, in the absence of activating light incident on the photochromic protective element, the photochromic protective element has maximum transmittance after a defined adaptation time. The defined adaptation time is preferably a maximum of 20 minutes, particularly preferably a maximum of 15 minutes. The defined adaptation time preferably depends on the material from which the photochromic protective element is formed.

[0009] The photochromic protective element can, for example, be formed at least partially by a base carrier, which is preferably formed at least partially from glass, polycarbonate, cellulose triacetate, or another suitable plastic, wherein, in particular in at least one exemplary embodiment, silver chloride molecules or the like are embedded in the base carrier. Alternatively or additionally, it is conceivable for organic photochromic molecules to be embedded in the base carrier. It is also conceivable for the base carrier to be formed by a component or element of the optical sun protection filter, for example by a polarization layer of the optical sun protection filter or the like. The photochromic protective element can, for example, be arranged as the outermost layer of the optical sun protection filter or at another position within the optical sun protection filter.Preferably, the photochromic protective element is at least partially curved, in particular at least when viewed in a main plane of extension of the photochromic protective element. A "main plane of extension" of a structural unit or element is understood to mean, in particular, a plane that is parallel to a largest side surface of the smallest possible imaginary cuboid that just completely encloses the structural unit, and in particular, runs through the center of the cuboid. However, it is also conceivable alternatively for the photochromic protective element to be designed without any curvature, in particular at least when viewed in the main plane of extension of the photochromic protective element.

[0010] Alternatively, it is also conceivable for the photochromic protective element to be designed as a coating or a film and, in particular, to be applied to a carrier element. The carrier element can, for example, be formed by at least one component or element of the sun protection device, in particular by the liquid crystal cell, the polarization layer, and / or a cellulose triacetate layer of the optical sun protection filter. In at least one exemplary embodiment, the photochromic protective element preferably bears against the carrier element. Particularly preferably, the photochromic protective element is attached to the carrier element. It is also conceivable for the carrier element to be formed integrally with the photochromic protective element."Integral" is understood in particular to mean at least materially connected, for example by a welding process, an adhesive process, an injection molding process, and / or another process deemed appropriate by a person skilled in the art, and / or advantageously formed in one piece, such as by production from a single casting and / or by production using a single- or multi-component injection molding process, and advantageously from a single blank. Alternatively or additionally, it is also conceivable for the photochromic protective element to be contained in an adhesive intended to bond at least two components or elements of the optical sun protection filter together. The photochromic protective element is preferably arranged on the liquid crystal cell. The photochromic protective element preferably rests against the liquid crystal cell.Particularly preferably, the photochromic protective element is attached to the liquid crystal cell. It is also conceivable for the photochromic protective element to be formed integrally with the liquid crystal cell. Alternatively, it is conceivable for at least one additional element, in particular at least one additional optical element of the optical sun protection filter, preferably at least one additional optical layer, to be arranged between the photochromic protective element and the liquid crystal cell. The photochromic protective element and the liquid crystal cell preferably overlap at least partially, particularly preferably at least substantially completely, at least viewed along a transverse axis of the liquid crystal cell. "At least substantially completely" is to be understood in particular as at least 50%, preferably at least 75%, and particularly preferably at least 90% of a total volume and / or total mass of an object.The transverse axis of the liquid crystal cell runs at least substantially perpendicular to a main extension plane of the liquid crystal cell. During use, the liquid crystal cell and / or the photochromic protective element is viewed, in particular, at least substantially parallel to the transverse axis. The term "substantially perpendicular" is intended here to define, in particular, an alignment of a direction relative to a reference direction, wherein the direction and the reference direction, in particular viewed in a projection plane, enclose an angle of 90°, and the angle has a maximum deviation of, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°."Substantially parallel" is understood here to mean, in particular, an alignment of a direction relative to a reference direction, in particular in a plane, wherein the direction has a deviation from the reference direction of, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°. The photochromic protective element preferably covers the liquid crystal cell at least partially, preferably at least substantially completely, in particular at least when viewed in a direction of hypothetical light incidence, particularly preferably in a direction of hypothetical solar radiation. The photochromic protective element and the liquid crystal cell form, in particular, part of a layered composite, wherein the photochromic protective element and the liquid crystal cell each form superimposed layers.Alternatively, it is conceivable for the liquid crystal cell to at least partially, preferably completely, cover the photochromic protective element, preferably at least when viewed in one direction of hypothetical light incidence, in particular in one direction of hypothetical solar radiation. Furthermore, it is also conceivable for the liquid crystal cell and the photochromic protective element not to overlap, preferably at least when viewed along the transverse axis of the liquid crystal cell. In at least one, in particular the preferred, embodiment, the optical sun protection filter can have at least two photochromic protective elements. Preferably, each photochromic protective element of the optical sun protection filter is assigned to one eye of the user. In principle, however, it would also be conceivable for the optical sun protection filter to have only one photochromic protective element for both eyes of the user.

[0011] In this context, the photochromic protective element, the liquid crystal cell, and / or the optical sunscreen filter should preferably be understood as an optical element. The "transmittance" of an optical element in this context should be understood to mean, in particular, the degree of transmission of sunlight through the optical element. This should preferably be understood to mean, in particular, the extent to which the visible spectrum of sunlight is absorbed and / or reflected by the optical element. Particularly preferably, this should be understood to mean a tint.

[0012] In this context, a "sun protection device" is understood to mean, in particular, a device intended to protect a user's eyes from, in particular, disturbing solar radiation. Preferably, this is understood to mean, in particular, a device intended to at least reduce solar radiation. Particularly preferably, the sun protection device is intended, in at least one operating state, to darken, in particular, disturbing solar radiation on the user's eyes. Various designs of the sun protection device that would appear appropriate to a person skilled in the art are conceivable, such as a sun visor, sunglasses, ski goggles, motorcycle goggles, safety goggles, or the like. "Provided" is understood to mean, in particular, specially programmed, designed, and / or equipped.The fact that an object is intended for a specific function should be understood in particular to mean that the object fulfils and / or executes this specific function in at least one application and / or operating state.

[0013] Furthermore, in this context, an "optical sun protection filter" is understood to mean, in particular, an optical filter which, in particular, forms a protective glass and / or a plastic protective glass, in particular for protection against disruptive solar radiation. This is preferably understood to mean, in particular, an optical protection filter with automatic darkening. The sun protection filter particularly preferably has at least one liquid crystal layer whose transmission can be switched. In at least one, particularly a preferred, embodiment, the optical sun protection filter can have at least two liquid crystal cells. Each liquid crystal cell of the optical sun protection filter is preferably assigned to one eye of the user. In principle, however, it would also be conceivable for the optical sun protection filter to have only one liquid crystal cell for both eyes of the user.Various liquid crystal cells are conceivable that would appear sensible to a person skilled in the art, such as, in particular, a TN liquid crystal cell using twisted nematic technology or a liquid crystal cell using 4DFFS technology. In principle, however, other designs of liquid crystal cells that would appear sensible to a person skilled in the art would also be conceivable, such as STN liquid crystal cells using super-twisted nematic technology, DSTN liquid crystal cells using double-super-twisted nematic technology, TSTN liquid crystal cells using triple-super-twisted nematic technology, VA liquid crystal cells using vertical alignment technology, in particular PVA / MVA liquid crystal cells using patterned vertical alignment and / or multi-domain vertical alignment technology, IPS liquid crystal cells using in-plane switching technology, FLCD liquid crystal cells, i.e. ferroelectric liquid crystal cells, and / or TN liquid crystal cells using guest-host technology.Preferably, the liquid crystal cell is at least partially curved, in particular at least when viewed in the main plane of extension of the liquid crystal cell. However, it is also conceivable for the liquid crystal cell to be designed without any curvature, in particular at least when viewed in the main plane of extension of the liquid crystal cell.

[0014] According to the invention, the sun protection device comprises at least one sensor unit, which is intended at least for detecting solar radiation. A "sensor unit" in this context is understood in particular to mean a unit intended to record at least one parameter and / or one physical property, wherein the recording can preferably take place actively, such as in particular by generating and transmitting an electrical measurement signal, and / or passively, such as in particular by detecting changes in the properties of a sensor component. Various sensor units that would appear appropriate to a person skilled in the art are conceivable for a sun protection device. The sensor unit preferably has at least one photocell, in particular a photodiode and / or in particular a solar cell. The photocell is preferably intended at least for optical detection of sunlight and / or artificial light.The sensor unit can, for example, be arranged at least partially in a spectacle frame of the optical sun protection device, between the liquid crystal cell and the photochromic protective element on the optical sun protection filter, as the outermost or innermost element of the sun protection device on the optical sun protection filter, in particular at least viewed along a direction of a hypothetical light incidence, particularly preferably in a direction of a hypothetical solar radiation and / or at least partially at further or different positions of the optical sun protection device.

[0015] According to the invention, the sun protection device comprises at least one control and / or regulating unit, which is at least intended to control and / or regulate the transmittance of the liquid crystal cell depending on solar radiation. In this context, a "control and / or regulating unit" is to be understood in particular as a unit with at least one control electronics unit. "Control electronics" is to be understood in particular as a unit with at least one electronic circuit, which preferably consists of voltage and comparison control modules. In principle, however, the control electronics can also be constructed in a more complex manner, for example by using an application-specific integrated circuit (ASIC) and / or a microcontroller module.It is conceivable that the control and / or regulating unit is designed, in at least one operating state, to control the at least one liquid crystal cell of the optical sun protection filter to generate a transmittance profile defined for a user, with at least two different transmittances. In this context, a "defined transmittance profile" is understood to mean, in particular, a local profile of the transmittance of the liquid crystal cell that is visible to a user, in particular a wearer.

[0016] It is further proposed that the optical sun protection filter has a total transmittance which is formed by at least one transmittance, in particular the one already mentioned, of the liquid crystal cell and the transmittance of the photochromic protective element. This can advantageously provide particularly high protection against solar radiation. This can advantageously ensure particularly high adaptability of the sun protection device to solar radiation. The optical sun protection filter preferably has a maximum total transmittance at the maximum transmittance of the photochromic protective element and at a maximum transmittance of the liquid crystal cell. The optical sun protection filter preferably has a minimum total transmittance at a minimum transmittance of the photochromic protective element and at a minimum transmittance of the liquid crystal cell.The transmittance of the liquid crystal cell is preferably adjustable as a function of the transmittance of the photochromic element. The transmittance of the liquid crystal cell is preferably adjustable by means of the control and / or regulating unit as a function of the transmittance of the photochromic protective element. Alternatively or additionally, it is also conceivable for the transmittance of the liquid crystal cell to be adjustable independently of the transmittance of the photochromic protective element. In at least one exemplary embodiment, it is alternatively conceivable for the transmittance of the photochromic protective element to depend on the transmittance of the liquid crystal cell. The maximum transmittance of the liquid crystal cell is preferably different from the maximum transmittance of the photochromic protective element, in particular smaller or larger.Alternatively, it is also conceivable that the maximum transmittance of the photochromic protective element corresponds to the maximum transmittance of the liquid crystal cell. It is conceivable that the minimum transmittance of the photochromic protective element is different, in particular greater or lesser, or equal to the transmittance of the liquid crystal cell. Preferably, the photochromic protective element and / or the liquid crystal cell are / are tint-free at the maximum transmittance. Alternatively, it is conceivable that the photochromic protective element and / or the liquid crystal cell have / have a basic tint at the maximum transmittance.

[0017] It is further proposed that the sun protection device has a protective layer, in particular a curved one, which is arranged as the outermost layer on the optical sun protection filter, wherein the photochromic protective element is applied to the protective layer or embedded in the protective layer. This can advantageously ensure particularly high protection for a wearer of the sun protection device. A particularly robust optical sun protection filter can advantageously be realized. Preferably, the protective layer forms the carrier element or the base carrier for the photochromic protective element. The protective layer is designed in particular as a cellulose triacetate layer. However, it is also conceivable for the protective layer to be formed from another material that appears appropriate to a person skilled in the art. In principle, it is also conceivable for the protective layer to be arranged at a different position on the optical sun protection filter.The protective layer is preferably provided to protect at least the optical sun protection filter from damage, in particular from damage caused by fats, oils, aromatic hydrocarbons, solvents and / or the like. The protective layer can, for example, be curved or curvature-free. Preferably, the protective layer is at least partially curved, in particular at least viewed in a main extension plane of the protective layer. Preferably, in at least one exemplary embodiment, in particular in which the photochromic protective element is applied to the protective layer, the main extension plane of the protective layer runs at least substantially parallel to a main extension plane of the photochromic protective element. Particularly preferably, a curvature of the protective layer is at least substantially identical to a curvature of the photochromic protective element.In this context, a "curvature" at a point on a surface that is different from zero is to be understood in particular as a deviation that increases quadratically with the distance from the point on the surface. The protective layer preferably covers the liquid crystal cell and / or the photochromic protective element at least partially, preferably completely, in particular at least when viewed along a direction of hypothetical light incidence, particularly preferably in a direction of hypothetical solar radiation. In at least one embodiment, the photochromic protective element is arranged between the protective layer and the liquid crystal cell.However, in at least one further embodiment, it is conceivable that the protective layer is arranged between the photochromic protective element and the liquid crystal cell, wherein the protective layer is in particular at least partially, preferably completely, covered by the photochromic protective element, preferably at least viewed in a direction of a hypothetical light incidence, in particular in a direction of a hypothetical solar radiation.

[0018] Furthermore, it is proposed that the optical sun protection filter has at least one polarization layer, in particular the one already mentioned above, wherein the photochromic protective element, in particular in at least one exemplary embodiment, is applied to the polarization layer or embedded in the polarization layer. This can advantageously ensure particularly high protection for a wearer of the sun protection device. The photochromic protective element can advantageously be integrated into the sun protection device in a particularly space-saving manner. The polarization layer can be curved or curvature-free. Preferably, the polarization layer is at least partially curved, in particular at least viewed in a main extension plane of the polarization layer.Preferably, in at least one embodiment, in particular in which the photochromic protective element is applied to the polarization layer, the main extension plane of the polarization layer runs at least substantially parallel to the main extension plane of the photochromic protective element. Particularly preferably, a curvature of the polarization layer is at least substantially identical to a curvature of the photochromic protective element. Preferably, the polarization layer covers the liquid crystal cell and / or the photochromic protective element at least partially, preferably completely, in particular at least viewed along a direction of hypothetical light incidence, particularly preferably in a direction of hypothetical solar radiation.

[0019] It is further proposed that the sun protection device, in particular at least in one exemplary embodiment, comprise a sensor unit, in particular the one already mentioned above, and a sensor cover, wherein the sensor cover at least partially covers a sensor surface of the sensor unit and is at least partially formed from a photochromic material. This can advantageously ensure high precision in adapting the optical sun protection filter to solar radiation while simultaneously ensuring particularly high robustness of the sun protection device. In this context, a "sensor cover" is understood to mean, in particular, an element that at least partially covers, in particular covers, the sensor unit, preferably in a detection direction of the sensor unit. Preferably, this is understood to mean an element that at least partially covers, in particular covers, the sensor surface of the sensor unit.This should preferably be understood as a cover that at least partially covers the sensor unit, preferably in a detection direction of the sensor unit, in particular for protection, such as against impacts or the like. Particularly preferably, this should be understood as a cover that at least partially covers the sensor unit, preferably in a detection direction of the sensor unit, in particular in order to integrate the sensor unit invisibly to an external observer. Furthermore, in this context, a "sensor surface" of the sensor unit should be understood as a detection surface of the sensor unit. This should preferably be understood as a surface of the sensor unit on which the sensor unit can detect incident light, in particular solar radiation. Particularly preferably, this should be understood as a cell surface of the sensor unit.The sensor surface is preferably directed forward, i.e., in particular, in the direction of a hypothetical viewing direction of a user. The sensor surface preferably extends substantially parallel to an end face of the sun protection device. In this context, the term "the sensor cover at least partially covers the sensor surface of the sensor unit" is understood to mean, in particular, that at least 10%, preferably at least 30%, and particularly preferably at least 50% of all surface normals of the sensor surface intersect the sensor cover in a direction away from the sensor unit. The sensor cover is preferably formed from a material that corresponds to the material of the photochromic protective element. The sensor cover is preferably arranged at a distance from the photochromic protective element. Alternatively, it is conceivable for the sensor cover to be formed by the photochromic protective element.In particular, the sensor cover has a maximum thickness, preferably at least viewed along a transverse axis of the sensor cover, which corresponds to a maximum thickness of the photochromic protective element, at least viewed along a transverse axis of the photochromic protective element. Preferably, the transverse axis of the sensor cover runs at least substantially perpendicular to a main extension plane of the sensor cover. Preferably, the transverse axis of the photochromic protective element runs at least substantially perpendicular to the main extension plane of the photochromic protective element. Alternatively, it is also conceivable for the sensor cover to be formed from a photochromic material that is different from a material from which the photochromic protective element is formed.Alternatively, it is conceivable that the maximum thickness of the sensor cover, preferably at least viewed along the transverse axis of the sensor cover, differs from the maximum thickness of the photochromic protective element, preferably at least viewed along the transverse axis of the photochromic protective element. Preferably, a transmittance of the sensor cover corresponds to the transmittance of the photochromic protective element. Preferably, a dependence of the transmittance of the sensor cover on solar radiation corresponds to the dependence of the transmittance of the photochromic protective element on solar radiation.

[0020] According to the invention, it is proposed that the sensor unit is arranged at least partially between the photochromic protective element and the liquid crystal cell. This advantageously makes it possible to realize a particularly simple structure of the sun protection device while simultaneously achieving a particularly high level of accuracy in adapting the optical sun protection filter to solar radiation. According to the invention, the sensor unit is provided to detect solar radiation after it has passed through the photochromic protective element. Preferably, a sensor surface, in particular the one already mentioned, overlaps at least partially with the photochromic protective element, at least when viewed along the transverse axis of the photochromic protective element. Preferably, the photochromic protective element covers the sensor surface at least partially, preferably completely, in particular at least when viewed in a detection direction of the sensor unit.

[0021] It is also proposed that the sun protection device comprise a spectacle frame, in particular the one already mentioned, which is provided for receiving the optical sun protection filter. This advantageously achieves a design of the sun protection device. A sun protection device can advantageously be provided that can be reliably arranged on the user's face. A spectacle-like design of the sun protection device can advantageously be provided. The spectacle frame preferably has at least one, preferably at least two, receiving area(s), each of which is / are provided for receiving a liquid crystal cell and / or a photochromic protective element of the optical sun protection filter. In this context, a "spectacle frame" is to be understood in particular as a frame that is provided for arranging the sun protection device on the user's face.Preferably, the frame is designed to accommodate the sun protection device on the nose and ears of the wearer. Particularly preferably, the spectacle frame is formed by a spectacle frame. It is conceivable that the sensor cover, particularly in at least one embodiment, is formed integrally with the spectacle frame.

[0022] Furthermore, the invention is based on a method for operating a sun protection device, in particular the one already mentioned. It is proposed that the transmittance of the liquid crystal cell is adjusted in at least one method step at least as a function of the transmittance of the photochromic protective element. This can advantageously achieve a particularly precise adaptation of an optical sun protection filter to solar radiation. Advantageously, a high level of comfort for a user of the sun protection device can be realized. Preferably, the transmittance of the liquid crystal cell is adjusted in at least one method step as a function of the solar radiation. Preferably, the transmittance of the liquid crystal cell is adjusted and / or regulated at least in the method step as a function of the solar radiation by means of the control and / or regulating unit.It is conceivable that the liquid crystal cell of the optical sun protection filter is controlled and / or regulated to generate a transmittance profile defined for a user. The solar radiation is preferably detected by the sensor unit. The solar radiation is preferably detected after passing through the photochromic protective element. It is also conceivable, particularly in at least one embodiment, that the solar radiation is detected after passing through the sensor cover.

[0023] Furthermore, a method for producing a sun protection device, in particular the one already mentioned, is proposed. Preferably, in at least one method step, the photochromic protective element and the liquid crystal cell are manufactured as a single piece using an injection molding process. Preferably, in at least one method step, the photochromic protective element and the protective layer are manufactured as a single piece using an injection molding process. Alternatively or additionally, in at least one method step, the sensor cover and the spectacle frame are manufactured as a single piece using an injection molding process. This advantageously allows for particularly simple production of the sun protection device.

[0024] The sun protection device according to the invention, the method according to the invention for operating a sun protection device and / or the method according to the invention for producing a sun protection device should not be limited to the application and embodiment described above. In particular, the sun protection device according to the invention, the method according to the invention for operating a sun protection device and / or the production of a sun protection device according to the invention can have a number of individual elements, components and units as well as method steps that differs from the number stated herein in order to fulfill a function described herein. Furthermore, in the value ranges stated in this disclosure, values ​​lying within the stated limits should also be considered disclosed and can be used as desired. Drawings

[0025] Further advantages will become apparent from the following description of the drawings. The drawings illustrate two exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0026] They show: Fig. 1 shows a sun protection device according to the invention in a first embodiment and a user wearing the sun protection device according to the invention, in a schematic front view, Fig. 2 shows a partial section of the sun protection device according to the invention with an optical sun protection filter in a schematic sectional view, Fig. 3 shows a schematic sequence of a method according to the invention for operating the sun protection device according to the invention, Fig. 4 shows a schematic sequence of a method according to the invention for producing the sun protection device according to the invention, Fig. 5 shows a sun protection device according to the invention in a second embodiment and a user wearing the sun protection device according to the invention, and Fig.6 shows a partial section of the sun protection device according to the invention in the second embodiment with an optical sun protection filter in a schematic sectional view. Description of the embodiments

[0027] The Figure 1 shows a sun protection device 10a. The sun protection device 10a is formed by sunglasses 12a. Alternatively, it is also conceivable for the sun protection device 10a to be designed as a sun visor, ski goggles, motorcycle goggles, safety goggles, or the like. The sunglasses 12a automatically darken depending on solar radiation. In principle, however, another design of the sun protection device 10a that would appear appropriate to a person skilled in the art would also be conceivable. The sun protection device 10a is intended, at least in one operating state, to darken the sunlight on the eyes of a user 36a.

[0028] The sun protection device 10a comprises at least one spectacle frame 26a. The spectacle frame 26a is formed by a spectacle frame. The spectacle frame 26a is essentially made of plastic. In principle, however, another material deemed appropriate by a person skilled in the art would also be conceivable, such as wood, metal, and / or a fiber composite material. The spectacle frame 26a has a base frame 38a and two spectacle temples movably mounted on the base frame 38a. The base frame 38a has a nose cutout 40a for resting on a nose of the user 36a. The spectacle temples are each provided for resting on the ears of the user 36a. The base frame 38a consists of two frame parts. In principle, however, it would also be conceivable for the base frame 38a to be formed as a single piece. The two frame parts are each formed by a shell part.A first frame part is arranged on a front side, and a second frame part is arranged on a back side. The frame parts are glued together, sealing a cavity between the frame parts. Components arranged within the base frame 38a are inserted into the frame parts before gluing.

[0029] The sun protection device 10a comprises at least one optical sun protection filter 14a. The base frame 38a is provided for receiving the optical sun protection filter 14a. The optical sun protection filter 14a is received in the spectacle frame 26a. The light transmittance of the optical sun protection filter 14a is adjustable. The optical sun protection filter 14a is substantially transparent, with the transmission of the optical sun protection filter 14a being at least partially electrically variable. The optical sun protection filter 14a has at least one liquid crystal cell 16a. The liquid crystal cell 16a is received in the spectacle frame 26a. The base frame 38a of the spectacle frame 26a has a recess in which the liquid crystal cell 16a is received.

[0030] The liquid crystal cell 16a has a liquid crystal plane 50a whose transmission is switchable. The liquid crystal cell 16a of the optical sun protection filter 14a is formed by a plastic liquid crystal cell. The liquid crystal cell 16a consists of several layers (see FIG. Figure 2). The number of layers is merely exemplary and can fundamentally vary. The liquid crystal cell 16a is formed by a TN liquid crystal cell. The liquid crystal cell 16a is therefore based on the twisted nematic technology. In principle, however, another design of the liquid crystal cell 16a that would appear reasonable to a person skilled in the art would also be conceivable. The liquid crystal plane 50a is formed by a translucent liquid crystal plane. The liquid crystal plane 50a has a liquid crystal layer 52a. A large number of crystal molecules and spacers are located in the liquid crystal layer 52a. A polyimide layer 54a is arranged on each side of the liquid crystal layer 52a. The polyimide layers 54a serve in particular to align the crystal molecules. An electrode layer 56a is arranged on each side of the polyimide layers 54a facing away from the liquid crystal layer 52a.The electrode layers 56a are each formed from a transparent indium tin oxide layer. Furthermore, a polarization layer 58a is located on each side of the liquid crystal plane 50a. The polarization layers 58a each serve to polarize incident light. A disk 60a is arranged on each side of the polarization layer 58a facing away from the liquid crystal plane 50a. The disks 60a are made of polycarbonate. An anti-reflection layer 62a and a hard layer 64a are applied to an outer side of each disk 60a. The liquid crystal cell 16a of the optical sunscreen filter 14a is curved over its entire extent.

[0031] The optical sun protection filter 14a comprises at least one photochromic protective element 20a. The photochromic protective element 20a is received in the recess of the spectacle frame 26a. The photochromic protective element 20a is formed as a coating or a film. The photochromic protective element 20a consists at least partially of silver chloride molecules, organic photochromic molecules, and / or the like. The sun protection device 10a comprises at least one protective layer 22a, to which the photochromic protective element 20a is applied. Alternatively, it is conceivable for the photochromic protective element 20a to be embedded in the protective layer 22a. In principle, it is also conceivable for the photochromic protective element 22a to be embedded in / applied on another component or element of the optical sun protection filter 14a.Furthermore, it is alternatively conceivable that the photochromic protective element 20a is contained in an adhesive intended to bond at least two components or elements of the optical sun protection filter 14a together. The protective layer 22a is formed as a cellulose triacetate layer 66a. However, it is also conceivable that the protective layer 22a is formed from another material that appears appropriate to a person skilled in the art. The protective layer 22a is arranged as the outermost layer on the optical sun protection filter 14a (cf. ). Figure 2). It is also conceivable in principle for the protective layer 22a to be arranged at a different position within the optical sun protection filter 14a. The protective layer 22a is provided to protect at least the optical sun protection filter 14a from damage, in particular from damage caused by fats, oils, aromatic hydrocarbons, solvents and / or the like. The protective layer 22a is curved, wherein it is also conceivable in principle for the protective layer 22a to be free of curvature, at least as viewed in a main extension plane of the protective layer 22a. The main extension plane of the protective layer 22a runs at least substantially parallel to a main extension plane of the photochromic protective element 20a. The curvature of the protective layer 22a is at least substantially identical to a curvature of the photochromic protective element 20a.The transmittance of the photochromic protective element 20a changes at least depending on the solar radiation. The photochromic protective element 20a is transparent and formed as a photochromic layer. The photochromic protective element 20a is designed to automatically darken with increasing light incidence, in particular solar radiation, so that the transmittance of the photochromic protective element 20a is reduced. The photochromic protective element 20a is designed at least to brighten with decreasing solar radiation, so that the transmittance of the photochromic protective element 20a is increased. In the absence of activating light incidence on the photochromic protective element 20a, the photochromic protective element 20a has a maximum transmittance after a defined adaptation time. The defined adaptation time is a maximum of 15 minutes.The defined adaptation time depends on a material from which the photochromic protective element 20a is formed.

[0032] The photochromic protective element 20a is arranged on the liquid crystal cell 16a (cf. Figure 2). The photochromatic protective element 20a rests against the liquid crystal cell 16a. The photochromatic protective element 20a is fastened to the liquid crystal cell 16a. It is also conceivable for the photochromatic protective element 20a to be formed integrally with the liquid crystal cell 16a. Alternatively, it is conceivable for at least one additional element, in particular at least one additional optical element of the optical sun protection filter 14a, preferably at least one additional optical layer, to be arranged between the photochromatic protective element 20a and the liquid crystal cell 16a. The photochromatic protective element 20a overlaps with the liquid crystal cell 16a at least substantially completely, at least when viewed along a transverse axis of the liquid crystal cell 16a. The transverse axis of the liquid crystal cell 16a runs at least substantially perpendicular to a main extension plane of the liquid crystal cell 16a.During use, the liquid crystal cell 16a and the photochromic protective element 20a are viewed at least substantially parallel to the transverse axis. The photochromic protective element 20a covers the liquid crystal cell 16a at least substantially completely, at least when viewed in a direction of hypothetical solar radiation. The photochromic protective element 20a and the liquid crystal cell 16a form part of a layered composite, with the photochromic protective element 20a and the liquid crystal cell 16a each forming superimposed layers.

[0033] The protective layer 22a covers the liquid crystal cell 16a and the photochromic protective element 20a at least partially, preferably completely, at least when viewed along a direction of hypothetical light incidence, particularly preferably in a direction of hypothetical solar radiation. The photochromic protective element 20a is arranged between the protective layer 22a and the liquid crystal cell 16a. However, in at least one further exemplary embodiment, it is conceivable for the protective layer 22a to be arranged between the photochromic protective element 20a and the liquid crystal cell 16a, wherein the protective layer 22a is in particular at least partially, preferably completely, covered by the photochromic protective element 20a, at least when viewed in a direction of hypothetical light incidence, particularly in a direction of hypothetical solar radiation.

[0034] Furthermore, the sun protection device 10a has a sensor unit 18a. The sensor unit 18a is provided for detecting solar radiation. The sensor unit 18a has a sensor surface 42a, which is provided for detecting solar radiation. The sensor unit 18a has one or more photodiodes, which are formed by a photocell. In principle, however, it would also be conceivable for the sensor unit 18a to have, for example, a solar cell. Furthermore, it would be conceivable, for example, for at least part of the sensor unit 18a, such as individual photodiodes, to be arranged as strips in a front region of the sun protection device 10a.

[0035] Furthermore, the sun protection device 10a has at least one control and / or regulating unit 44a. The control and / or regulating unit 44a is provided to control the transmittance of the optical sun protection filter 14a depending on solar radiation. For this purpose, the control and / or regulating unit 44a is connected to the sensor unit 18a in a manner not further visibly shown. Furthermore, the control and / or regulating unit 44a is connected to the liquid crystal cell 16a of the optical sun protection filter 14a in a manner not further visibly shown. The control and / or regulating unit 44a is electrically connected to the electrode layers 56a of the liquid crystal cell 16a (not further shown). The control and / or regulating unit 44a is arranged in the spectacle frame 26a. The control and / or regulating unit 44a is arranged in the base frame 38a of the spectacle frame 26a above the nose cutout 40a. The control and / or regulating unit 44a is integrated into the spectacle frame 26a.The control and / or regulating unit 44a is arranged in a receiving area of ​​the base frame 38a. The receiving area of ​​the base frame 38a is arranged above the nose cutout 40a. The receiving area of ​​the base frame 38a is formed by a recess. In principle, however, another arrangement of the control and / or regulating unit 44a that would be deemed appropriate by a person skilled in the art would also be conceivable.

[0036] In an operating state, the sensor unit 18a is provided to at least partially provide energy for controlling the liquid crystal cell 16a of the optical sun protection filter 14a. During operation of the sun protection device 10a, the sensor unit 18a is provided to completely provide energy for controlling the liquid crystal cell 16a of the optical sun protection filter 14a. During operation of the sun protection device 10a, the sensor unit 18a is provided to completely obtain the energy required to control the liquid crystal cell 16a of the optical sun protection filter 14a. The sun protection device 10a is designed to be battery-free.

[0037] The optical sun protection filter 14a has a total transmittance, which is formed at least by a transmittance of the liquid crystal cell 16a and the transmittance of the photochromic protective element 20a. The optical sun protection filter 14a has a maximum total transmittance at a maximum transmittance of the photochromic protective element 20a and at a maximum transmittance of the liquid crystal cell 16a. The transmittance of the liquid crystal cell 16a is adjustable depending on the transmittance of the photochromic protective element 20a. The transmittance of the liquid crystal cell 16a is adjustable by means of the control and / or regulating unit 44a depending on the transmittance of the photochromic protective element 20a. Alternatively or additionally, it is also conceivable for the transmittance of the liquid crystal cell 16a to be adjustable independently of the transmittance of the photochromic protective element 20a.The maximum transmittance of the liquid crystal cell 16a differs from the maximum transmittance of the photochromic protective element 20a, in particular, it may be smaller or larger. Alternatively, it is also conceivable for the maximum transmittance of the liquid crystal cell 16a to correspond to the maximum transmittance of the photochromic protective element 20a. This applies analogously to the minimum transmittances of the liquid crystal cell 16a and the photochromic protective element 20a. The photochromic protective element 20a and the liquid crystal cell 16a are tint-free at the maximum transmittance. Alternatively, it is conceivable for the photochromic protective element 20a and / or the liquid crystal cell 16a to have / have a basic tint at the maximum transmittance.

[0038] The sensor unit 18a is arranged at least partially between the photochromic protective element 20a and the liquid crystal cell 16a. The sensor unit 18a is intended at least to detect solar radiation after passing through the photochromic protective element 20a. The sensor surface 42a at least partially overlaps with the photochromic protective element 20a, at least when viewed along the transverse axis of the photochromic protective element 20a. The photochromic protective element 20a completely covers the sensor surface 42a, at least when viewed in a detection direction of the sensor unit 18a.

[0039] Figure 3shows a flow diagram of a method 28a for operating the sun protection device 10a. In at least one method step 46a, solar radiation is detected by means of the sensor unit 18a. In at least one method step 30a, the transmittance of the liquid crystal cell 16a is adjusted as a function of the solar radiation. The transmittance of the liquid crystal cell 16a is controlled and / or regulated at least in method step 30a as a function of the solar radiation by means of the control and / or regulating unit 44a. It is conceivable that the liquid crystal cell 16a is controlled and / or regulated at least in method step 30a to generate a transmittance profile defined for a user 36a. In at least method step 30a, the transmittance of the liquid crystal cell 16a is adjusted at least as a function of the transmittance of the photochromic protective element 20a.The solar radiation is detected at least in method step 46a after passing through the at least one photochromic protective element 20a, in particular by means of the sensor unit 18a. Figure 4 schematically shows a method 32a for producing a sun protection device 10a. In at least one method step 48a of the method 32a, a photochromic protective element 20a is present separately from a liquid crystal cell 16a and / or from a protective layer 22a. In at least one further method step 34a, the photochromic protective element 20a is applied to the protective layer 22a, in particular using a coating process, or is manufactured integrally with the protective layer 22a. It is conceivable that the sensor unit 18a is overmolded by the optical sun protection filter 14a, at least in the method step 34a.

[0040] In the Figures 5 and 6A further embodiment of the invention is shown. The following description and the drawings are essentially limited to the differences between the embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, reference is also made to the drawings and / or the description of the other embodiment, in particular to the Figures 1 to 4 To distinguish the embodiments, the letter a is added to the reference numerals of the embodiment in the Figures 1 to 4 In the example of the Figures 5 and 6the letter a is replaced by the letter b. In particular, the methods for the further exemplary embodiment are analogous to the method described so far, whereby the methods can differ from the previously described embodiment due to the described differences with regard to the technical design of the sun protection device of the further exemplary embodiment.

[0041] Figure 5shows a sun protection device 10b. The sun protection device 10b is formed by sunglasses 12b. The sun protection device 10b comprises at least one eyeglass frame 26b. The sun protection device 10b comprises at least one optical sun protection filter 14b. The optical sun protection filter 14b has two liquid crystal cells 16b. The liquid crystal cells 16b are mirror-symmetrical to one another. The liquid crystal cells 16b are accommodated in the eyeglass frame 26b. A base frame 38b of the eyeglass frame 26b has two recesses in which the liquid crystal cells 16b are accommodated. The liquid crystal cells 16b are each arranged on opposite sides of a nose cutout 40b. Each of the liquid crystal cells 16b is assigned to a respective eye of a user 36b. The optical sun protection filter 14b comprises two photochromic protective elements 20b.The photochromic protective elements 20b are arranged analogously to the liquid crystal cells 16b. The transmittance of the photochromic protective elements 20b changes at least depending on the solar radiation.

[0042] The photochromic protective elements 20b are each arranged on one of the liquid crystal cells 16b. Each of the photochromic protective elements 20b overlaps at least substantially completely with one of the liquid crystal cells 16b, at least when viewed along a transverse axis of the respective liquid crystal cell 16b. The transverse axis of the respective liquid crystal cell 16b runs at least substantially perpendicular to a main extension plane of the respective liquid crystal cell 16b. The photochromic protective elements 20b each cover one of the liquid crystal cells 16b at least substantially completely, at least when viewed in a direction of hypothetical solar radiation. The photochromic protective elements 20b are each at least partially curved, at least when viewed in a main extension plane of the respective photochromic protective element 20b.

[0043] A control and / or regulating unit 44b is arranged in the base frame 38b of the spectacle frame 26b between the recesses for the liquid crystal cells 16b. The sun protection device 10b comprises at least one sensor unit 18b and a sensor cover 24b. The sensor cover 24b at least partially covers a sensor surface 42b of the sensor unit 18b. The sensor surface 42b extends at least substantially parallel to an end face of the sun protection device 10b. The sensor cover 24b covers the sensor surface 42b at least substantially completely. The sensor unit 18b is arranged in the spectacle frame 26b. The sensor unit 18b is arranged in the base frame 38b of the spectacle frame 26b above the nose cutout 40b. The sensor unit 18b is integrated into the spectacle frame 26b. The base frame 38b of the spectacle frame 26b has a receiving area above the nose cutout 40b, which is formed by a recess.The sensor unit 18b is arranged in the receiving area of ​​the base frame 38b. The sensor cover 24b covers the receiving area of ​​the base frame 38b of the spectacle frame 26b. The sensor cover 24b is formed by a plate-shaped cover. The sensor cover 24b is at least partially formed from a photochromic material. The sensor cover 24b is formed from a material that corresponds to the material of the photochromic protective elements 20b. The sensor cover 24b is arranged at a distance from the photochromic protective element 20b. The sensor cover 24b has a maximum thickness, at least viewed along a transverse axis of the sensor cover 24b, which corresponds to a maximum thickness of the photochromic protective elements 20b, at least viewed along a respective transverse axis of the respective photochromic protective element 20b.The transverse axis of the sensor cover 24b runs at least substantially perpendicular to a main extension plane of the sensor cover 24b. The respective transverse axes of the photochromic protective elements 20b run at least substantially perpendicular to a main extension plane of the respective photochromic protective element 20b. Alternatively, it is conceivable that the maximum thickness of the sensor cover 24b, at least viewed along the transverse axis of the sensor cover 24b, is different from the maximum thickness of the photochromic protective elements 20b, at least viewed along the respective transverse axis of the photochromic protective elements 20b. A transmittance of the sensor cover 24b corresponds to the transmittance of the photochromic protective elements 20b. A dependence of the transmittance of the sensor cover 24b on the solar radiation corresponds to the dependence of the transmittance of the photochromic protective elements 20b on the solar radiation.

[0044] The optical sun protection filter 14b comprises at least one polarization layer 58b (cf. Figure 6). At least one polarization layer 58b is arranged on each of the liquid crystal cells 16b. The photochromic protective elements 20b are each embedded in one of the polarization layers 58b. Alternatively, it is also conceivable for the photochromic protective elements 20b to be applied to each of the polarization layers 58b. The polarization layers 58b are at least partially curved, at least when viewed in a main plane of extension of the respective polarization layer 58b. However, it is also conceivable in principle for the polarization layers 58b to be curvature-free. The polarization layers 58b each cover the liquid crystal cells 16b at least partially, preferably completely, in particular at least when viewed along a direction of a hypothetical light incidence, particularly preferably in a direction of a hypothetical solar radiation.

Claims

1. Sun protection device (10a; 10b), in particular sunglasses (12a; 12b), having at least one optical sun protection filter (14a; 14b) which has at least one liquid crystal cell (16a; 16b), having a sensor unit (18a; 18b) which is configured at least for detecting solar irradiation, and having at least one control and / or regulating unit (44a), which is configured at least for controlling and / or regulating a transmittance of the liquid crystal cell (16a; 16b) depending on solar irradiation, wherein the optical sun protection filter (14a; 14b) has at least one photochromatic protection element (20a; 20b) whose transmittance changes in particular at least depending on the solar irradiation, wherein the sensor unit (18a; 18b) is configured for detecting a solar irradiation after passing the photochromatic protection element (20a; 20b), characterized in that the sensor unit (18a; 18b) is at least partially arranged between the photochromatic protection element (20a) and the liquid crystal cell (16a; 16b).

2. Sun protection device (10a; 10b) according to claim 1, characterized in that the optical sun protection filter (14a; 14b) has a total transmittance which is formed at least by a transmittance of the liquid crystal cell (16a; 16b) and the transmittance of the photochromatic protection element (20a; 20b).

3. Sun protection device (10a; 10b) according to claim 1 or 2, characterized by an, in particular, curved, protective layer (22a) which is arranged as the outermost layer on the optical sun protection filter (14a), the photochromatic protection element (20a) being applied on the protective layer (22a) or being embedded in the protective layer (22a).

4. Sun protection device (10a; 10b) according to one of the preceding claims, characterized in that the optical sun protection filter (14a; 14b) has at least one polarisation layer (58a; 58b), wherein the photochromatic protection element (20b) is applied on the polarisation layer (58b) or is embedded in the polarisation layer (58b).

5. Sun protection device (10a; 10b) according to one of the preceding claims, characterized by a sensor unit (18a; 18b) and a sensor cover (24a; 24b), wherein the sensor cover (24a; 24b) at least partially covers a sensor surface (42a; 42b) of the sensor unit (18a; 18b) and is at least partially formed from a photochromatic material.

6. Sun protection device (10a, 10b) according to one of the preceding claims, characterized by a spectacle frame (26a; 26b) configured for receiving the optical sun protection filter (14a; 14b).

7. Method (28a; 28b) of operating a sun protection device (10a; 10b) according to one of the preceding claims, characterized in that the transmittance of the liquid crystal cell (16a; 16b) is adjusted in at least one method step (30a; 30b) at least in dependence on the transmittance of the photochromatic protection element (20a; 20b).