SUN PROTECTION DEVICE

Description

State of the art

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

[0002] US 8,081,262 B1 has already proposed a sun protection device with at least one optical sun protection filter having at least one liquid crystal cell, with at least one sensor provided for detecting solar radiation, and with at least one control and / or regulating unit provided for controlling and / or regulating a transmittance of the optical sun protection filter depending on solar radiation.

[0003] 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

[0004] The invention is based on a sun protection device, in particular sunglasses, with at least one optical sun protection filter which has at least one liquid crystal cell, with at least one sensor unit which is provided for detecting solar radiation, and with at least one control and / or regulating unit which is provided for controlling and / or regulating a transmittance of the optical sun protection filter depending on solar radiation.

[0005] It is proposed that the control and / or regulating unit is provided in at least one operating state to enable 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

[0006] to control. The control and / or regulating unit is provided 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 from a viewing direction of the user, in particular of the wearer, with at least two different transmittances. The control and / or regulating unit is provided in at least one operating state to control the at least one liquid crystal cell of the optical sun protection filter to generate a viewing angle-dependent transmittance profile. In at least one operating state, the liquid crystal cell is controlled to generate a viewing angle-dependent transmittance which results in a defined transmittance profile from a viewing direction of the user. According to the invention, the at least one optical sun protection filter has at least two liquid crystal cells.According to the invention, each liquid crystal cell of the optical sun protection filter is assigned to one eye of the user. However, it would also be conceivable according to the invention for the at least one optical sun protection filter to have only one liquid crystal cell for both eyes of the user. In this context, a "sun protection device" is to be understood in particular as a device that is intended to protect the eyes of a user from, in particular, disturbing solar radiation. Preferably, this is to be understood in particular as a device that is 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 and / or, particularly preferably, sunglasses. Furthermore, in this context, an "optical sun protection filter" is understood to mean, in particular, an optical filter that forms, in particular, a protective glass and / or a plastic protective glass, in particular for protection against disruptive solar radiation. This is understood to mean, in particular, an optical filter whose light transmittance is adjustable. This is understood to mean, in particular, an optical protective filter with automatic darkening. The sun protection filter has at least one liquid crystal layer whose transmission can be switched. The optical sun protection filter has at least one liquid crystal cell.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. 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.In this context, a "sensor unit" is understood to mean, in particular, a unit designed to record at least one parameter and / or a physical property. The recording can take place actively, such as by generating and transmitting an electrical measurement signal, and / or passively, such as by detecting changes in the properties of a sensor component. Various sensor units for a sun protection device that would appear appropriate to a person skilled in the art are conceivable. The sensor unit preferably comprises at least one photocell, in particular a photodiode and / or in particular a solar cell. The photocell is preferably designed, in particular, for optical detection of sunlight and / or artificial light. Furthermore, in this context, a "control and / or regulating unit" is understood to mean, in particular, a unit with at least one control electronics unit.The term "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, in particular through the use of an application-specific integrated circuit (ASIC) and / or a microcontroller module.

[0007] In this context, the "transmittance of the optical sun protection filter" is to be understood in particular as a degree of transmission of sunlight through the optical sun protection filter. Preferably, this is to be understood in particular as the extent to which the visible spectrum of sunlight is absorbed and / or reflected by the optical sun protection filter. Particularly preferably, this is to be understood in particular as a tint. Furthermore, in this context, a "defined transmittance profile" is to be understood in particular as a local profile of the transmittance of the liquid crystal cell that is visible to a user, in particular a wearer. According to the invention, this is to be understood in particular as a profile of the transmittance of the liquid crystal cell that is visible from a viewing direction of the user, in particular the wearer, and which has at least two different transmittances at a fixed point in time.This is preferably 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, and that is generated by the optical properties of the liquid crystals of the liquid crystal cell itself. According to the invention, the defined transmittance profile arises in particular from the angular dependence of the liquid crystal cell, i.e., an influence on the transmittance of the liquid crystal cell depending on the viewing angle of the user's eye to the crystal molecules and depending on the orientation of the crystal molecules. With increasing bending of the viewing direction or the viewing angle relative to the crystal molecules of the liquid crystal cell, in particular the transmittance of the liquid crystal cell decreases and absorption increases.Furthermore, in this context, "differentiated transmittances" should be understood in particular to mean that the at least one liquid crystal cell has, at least from the perspective of the user, in particular the wearer, at least two regions that have a significantly different hue from one viewing direction or viewing angle of the user, in particular the wearer. A "significantly different hue" should be understood in particular to mean a difference between the hues of at least 1%, preferably of at least 10%, and particularly preferably of at least 30%. The hue defines in particular a percentage of light absorption at least in the visible light range, in particular in a wavelength range from 380 nm to 780 nm. "Provided" should be understood in particular to mean 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.

[0008] The sun protection device according to the invention can, in particular, achieve a pleasant darkening effect for the user. In particular, the transmittance profile of the liquid crystal cell, which occurs from the user's viewing direction, can provide the user with a darkening effect adapted to the sunlight. In particular, a high level of comfort and advantageous usability of the sun protection device can be achieved.

[0009] According to the invention, the control and / or regulating unit is provided, in at least one operating state, to control the at least one liquid crystal cell of the optical sun protection filter to maintain the transmittance profile defined for the user. Preferably, the control and / or regulating unit is provided, with constant solar radiation relative to the sun protection device, to control the at least one liquid crystal cell of the optical sun protection filter to maintain the transmittance profile defined from a viewing direction of the user. According to the invention, "maintaining the defined transmittance profile" in this context is to be understood in particular as maintaining the transmittance profile defined from a viewing direction of the user at a given point in time over an unlimited period of time.This should preferably be understood in particular as maintaining the transmittance profile present at a point in time, defined from a viewing direction of the user, over a period of time in which solar radiation relative to the sun protection device remains at least substantially the same. Particularly preferably, this should in particular be understood as maintaining the orientation of the crystal molecules of the liquid crystal cell present at a fixed point in time, in which the defined transmittance profile is generated from a viewing direction of the user, over a period of time in which solar radiation relative to the sun protection device remains at least substantially the same. As a result, a transmittance profile in the liquid crystal cell can be reliably and permanently maintained. In particular, a profile visible from the user's viewing direction can thereby be permanently generated.This ensures that a user is provided with maximum visibility while maintaining optimal darkening.

[0010] Furthermore, it is proposed that, for a user, a lower transmittance of the at least one liquid crystal cell is arranged above a higher transmittance in the transmittance profile. According to the invention, the transmittance profile extends from top to bottom when viewed by the user, with transmittance increasing from top to bottom. Darkening decreases in the transmittance profile, in particular from top to bottom when viewed by the user. "Above" should be understood in particular to mean above in a regular position of the sun protection device. Preferably, this should be understood in particular to mean above when the sun protection device is worn and the user is in an upright posture. In particular, this should therefore be understood in particular to mean above from the user's perspective.This makes it possible to achieve a particularly pleasant dimming effect for the user. Preferably, this allows a top side of the liquid crystal cell facing the sun, onto which the sun's rays radiate onto the at least one liquid crystal cell, to be darkened more intensely, particularly when the operator is in an upright position. This ensures that the user is provided with maximum visibility while maintaining optimal dimming.

[0011] According to the invention, the control and / or regulating unit is provided, in at least one operating state, to adjust the strength and / or extent of the transmittance profile of the at least one liquid crystal cell of the optical sun protection filter for a user depending on solar radiation. Preferably, the control and / or regulating unit is provided, in at least one operating state, to adjust the extent of the transmittance profile of the at least one liquid crystal cell of the optical sun protection filter from a viewing direction of the user depending on solar radiation, thereby changing an average transmittance across the surface of the at least one liquid crystal cell for a user.The control and / or regulating unit is preferably provided for setting a fixed transmittance profile of the at least one liquid crystal cell of the optical sun protection filter, defined from a viewing direction of the user, wherein a position of the transmittance profile is changed depending on solar radiation. With increasing solar radiation, an average transmittance across the surface of the at least one liquid crystal cell decreases from a viewing direction of the user. Preferably, the transmittance profile extends further and further, in particular from top to bottom, into the liquid crystal cell from a viewing direction of the user as the solar radiation increases. This makes it possible to achieve, in particular, a pleasant and customized darkening that is advantageous for a user. Furthermore, it is possible to provide a user with maximum visibility with optimal darkening.

[0012] Alternatively or additionally, it would also be conceivable for the control and / or regulating unit to be provided, in at least one operating state, to set a strength and / or extent of the transmittance profile of the at least one liquid crystal cell of the optical sun protection filter for a user depending on at least one user input. Preferably, the control and / or regulating unit to be provided, in at least one operating state, to set a strength and / or extent of the transmittance profile of the at least one liquid crystal cell of the optical sun protection filter for a user depending on a user-adjustable level for adjusting the transmittance profile. Preferably, a user input and / or an input of the user-adjustable level is made via an input unit.Particularly preferably, the user input defines a correction factor, a multiplication factor, and / or an extreme value, in particular a minimum and / or particularly preferably a maximum value, of the transmittance profile defined for a user, in particular relative to solar radiation. In principle, however, it would also be conceivable for the transmittance profile defined for a user to be set to a defined value by a user using the user input. In this context, an "input unit" is understood to mean, in particular, a unit via which settings can be made, in particular by an operator. Preferably, this is understood to mean, in particular, a unit designed to receive an input value from an operator during a setting process.Preferably, the unit is designed to be contacted directly by an operator, whereby a touch of the input unit and / or an actuating force exerted on an operating element of the input unit and / or a position of the input unit changed by an operator is sensed. In principle, however, only a current position of the input unit can be detected. This allows the permeability profile defined for a user to be individually adjusted and / or set, in particular by the user.

[0013] It is further proposed that the control and / or regulating unit is provided, in at least one operating state, to control and / or regulate a drive voltage for driving the at least one liquid crystal cell of the optical sun protection filter to a value below a saturation field strength of the at least one liquid crystal cell. According to the invention, the control and / or regulating unit is provided, in at least one operating state, to control and / or regulate a drive voltage for driving the at least one liquid crystal cell of the optical sun protection filter to a value below a saturation voltage required to provide a saturation field strength of the at least one liquid crystal cell.According to the invention, the control and / or regulating unit is provided to control and / or regulate a drive voltage for driving the at least one liquid crystal cell of the optical sun protection filter to a value below the saturation voltage. Particularly preferably, the difference between a light area and a dark area of ​​the liquid crystal cell increases with increasing drive voltage. As long as the drive voltage is operated below the saturation voltage required to provide a saturation field strength of the at least one liquid crystal cell, the difference between the light and dark areas of the liquid crystal cell in particular remains. As soon as the drive voltage reaches the saturation voltage required to provide a saturation field strength of the at least one liquid crystal cell, the user would in particular perceive a brightening again in an upper area.In this context, a "drive voltage" is to be understood in particular as a voltage with which electrodes, in particular electrode layers, of the at least one liquid crystal cell are applied to generate an electric field for aligning a liquid crystal layer of the at least one liquid crystal cell. Furthermore, in this context, a "saturation field strength" is to be understood in particular as a minimum limiting field strength required for at least approximately complete alignment, in particular ordering, of the liquid crystal layer of the at least one liquid crystal cell. Preferably, this is to be understood in particular as a minimum limiting field strength required to induce a dipole moment required for complete alignment of the liquid crystal layer of the at least one liquid crystal cell.This advantageously allows a simple design to provide a transmittance profile for the at least one liquid crystal cell of the optical sun protection filter. Furthermore, this allows advantageously low energy consumption of the sun protection device to be achieved, particularly with optimal darkening.

[0014] It is further proposed that the at least one liquid crystal cell of the optical sun protection filter be at least partially curved. Preferably, the at least one liquid crystal cell of the optical sun protection filter is curved over a substantial extent. Preferably, the at least one liquid crystal cell of the optical sun protection filter is substantially curved. In this context, "at least partially curved" is to be understood in particular to mean that the liquid crystal cell, viewed in at least one plane, has a curvature that is different from zero. A "curvature" at a point on a surface that is different from zero is to be understood in this context in particular to mean a deviation from a tangential plane that increases quadratically with the distance from the point on the surface.In this context, "significantly curved" is to be understood in particular as meaning that a maximum distance of the liquid crystal cell from a tangential plane at a center of the liquid crystal cell, viewed perpendicular to the tangential plane, is at least 2 mm, preferably at least 4 mm, and particularly preferably at least 6 mm. This makes it possible to provide, in particular, an advantageously high optical quality of the sun protection device. In particular, an advantageously small angular difference between the beam paths of the individual eyes can be achieved. In particular, irritating visibility, especially in an edge region of the sun protection device, can be avoided. Furthermore, a high level of ergonomics of the sun protection device can be achieved. In particular, it can be prevented that the user's eyelashes touch the at least one liquid crystal cell.

[0015] Furthermore, it is proposed that the at least one liquid crystal cell of the optical sun protection filter be formed by a plastic liquid crystal cell. Preferably, the liquid crystal cell consists at least partially of a plastic, in particular of polycarbonate. Particularly preferably, at least one boundary plate of the liquid crystal cell consists of a plastic, in particular of polycarbonate. In principle, however, it would also be conceivable for the at least one liquid crystal cell of the optical sun protection filter to be formed by a glass liquid crystal cell. In this case, it would be particularly conceivable for the at least one liquid crystal cell to be made at least partially of curved glass. This advantageously makes it possible to keep the weight of the sun protection device low.Furthermore, the use of plastic liquid crystal cells can provide advantageously high UV protection, in particular through absorption in the plastic, especially in the polycarbonate.

[0016] It is further proposed that the sun protection device comprise a spectacle frame designed to receive the optical sun protection filter. The spectacle frame preferably comprises two receiving areas, each designed to receive a liquid crystal cell of the at least one optical sun protection filter. In this context, a "spectacle frame" is understood to mean, in particular, a frame designed to accommodate the sun protection device on the user's face. Preferably, the frame is designed to accommodate the sun protection device on the user's nose and ears. Particularly preferably, the spectacle frame is formed by a spectacle frame. This allows, in particular, an advantageous design of the sun protection device to be achieved. The sun protection device can thus preferably be reliably positioned on the user's face.In particular, a spectacle-like design of the sun protection device can be provided.

[0017] According to the invention, the at least one sensor unit is designed to fully provide energy for controlling the at least one liquid crystal cell of the optical sun protection filter in at least one operating state. During operation of the sun protection device, the at least one sensor unit is designed to fully provide energy for controlling the at least one liquid crystal cell of the optical sun protection filter.

[0018] During operation of the sun protection device, the at least one sensor unit is provided to fully obtain the energy required to control the at least one liquid crystal cell of the optical sun protection filter. According to the invention, the sun protection device is designed without a battery. This makes it possible, in particular, to dispense with an external power supply, such as a battery and / or an accumulator. A self-sufficient sun protection device can be provided.

[0019] It is further proposed that the at least one sensor unit has at least one photodiode. Preferably, the sensor unit has at least one solar cell. Preferably, the sensor unit is formed by a solar cell and / or photocell. This makes it possible to provide an advantageously reliable sensor unit with an advantageously high energy yield. Furthermore, an external energy supply such as a battery and / or an accumulator can be dispensed with. When using a photocell, a sensor unit can be provided in particular, by means of which light in a non-visible range, such as infrared light, can be detected and preferably utilized. A self-sufficient sun protection device can be provided.In particular, this can ensure that, with increasing solar radiation, more energy is available to control the at least one liquid crystal cell of the optical sun protection filter. Energy generation is thus advantageously adapted to energy demand.

[0020] Furthermore, the invention is based on a method for operating the sun protection device. It is proposed that the at least one liquid crystal cell of the optical sun protection filter is controlled and / or regulated to generate a transmittance profile defined for a user. According to the invention, the at least one liquid crystal cell of the optical sun protection filter is controlled to generate a transmittance profile defined from a viewing direction of the user with at least two different transmittances. This makes it possible, in particular, to achieve a darkening that is advantageously pleasant for a user. In particular, the user can be provided with darkening adapted to solar radiation through the transmittance profile of the liquid crystal cell occurring from a viewing direction of the user.This ensures maximum visibility for the user while providing optimal darkening. In particular, it can provide a high level of comfort and advantageous usability of the sun protection device.

[0021] Furthermore, it is proposed that the at least one liquid crystal cell of the optical sun protection filter is controlled and / or regulated to generate a transmittance profile defined for a user depending on solar radiation. According to the invention, the at least one liquid crystal cell of the optical sun protection filter is controlled to generate a transmittance profile defined from a viewing direction of the user depending on solar radiation. This makes it possible, in particular, to achieve a darkening effect that is advantageously pleasant for a user. In particular, this makes it possible to adapt a transmittance profile to the current solar radiation. In particular, an individual adaptation of the transmittance profile to the solar radiation can be achieved.

[0022] It is further proposed that the at least one liquid crystal cell of the optical sun protection filter is controlled and / or regulated to generate a transmittance profile defined for a user depending on at least one user input. A user input is preferably made via an input unit. Particularly preferably, the user input defines in particular a correction factor, a multiplication factor and / or an extreme value, in particular a minimum and / or particularly preferably a maximum value, of the transmittance profile defined for a user, in particular relative to the solar radiation. In principle, however, it would also be conceivable for the transmittance profile defined for a user to be set to a defined value by a user by means of the user input.This allows the permeability profile defined for a user to be individually adjusted and / or set. This ensures that the user is provided with maximum visibility while maintaining optimal darkening. In particular, it can provide a high level of comfort and advantageous usability of the sun protection device.

[0023] It is further proposed that the at least one liquid crystal cell of the optical sun protection filter be controlled and / or regulated to generate a transmittance profile defined for a user, depending on a user-adjustable level for adjusting the transmittance profile. Preferably, the level can be selected via an input unit. Particularly preferably, the user-adjustable level defines, in particular, a correction factor and / or a multiplication factor of the transmittance profile defined for a user, in particular relative to the solar radiation. As a result, the transmittance profile defined for a user can be individually adjusted and / or set, in particular by a user. This makes it possible to provide a user with maximum visibility while achieving optimal darkening.In particular, a high level of comfort and advantageous usability of the sun protection device can be provided.

[0024] The sun protection device according to the invention and the method are not intended to be limited to the application and embodiment described above. In particular, the sun protection device according to the invention and the method may have a number of individual elements, components, and units that differs from the number stated herein to fulfill a function described herein. Drawings

[0025] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment 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 with a sun protection filter which has two liquid crystal cells, with a sensor unit and with a control and regulating unit and a user wearing the sun protection device according to the invention in a schematic front view, Fig. 2 shows the sun protection device according to the invention and the user wearing the sun protection device according to the invention in a schematic side view, Fig. 3 shows the sun protection device according to the invention and the user wearing the sun protection device according to the invention in a schematic sectional view along the section line III, Fig. 4 shows a partial section IV-IV of the sun protection device according to the invention with the sun protection filter in a schematic sectional view, Fig.5 the sun protection device according to the invention and the user in a schematic sectional view along the section line III with different viewing angles of the user, Fig. 6 the sun protection device according to the invention and the user in a schematic sectional view along the section line VI with different viewing angles of the user, Fig. 7 a diagram of a transmission of the liquid crystal cells of the sun protection filter as a function of a control voltage, Fig. 8A a transmittance curve of the liquid crystal cells of the sun protection device according to the invention in a first state, Fig. 8B a transmittance curve of the liquid crystal cells of the sun protection device according to the invention in a second state, Fig. 8C a transmittance curve of the liquid crystal cells of the sun protection device according to the invention in a third state, Fig.Fig. 8 shows a transmittance profile of the liquid crystal cells of the sun protection device according to the invention in a fourth state, Fig. 9 shows a flow diagram of a method for operating the sun protection device according to the invention, and Fig. 10 shows a schematic circuit diagram of the control and regulating unit of the sun protection device according to the invention. Description of the embodiment

[0027] The Figures 1 and 2show a sun protection device 10. The sun protection device 10 is formed by sunglasses. The sun protection device 10 is formed by sunglasses which automatically darken depending on solar radiation. In principle, however, another design of the sun protection device 10 that would appear appropriate to a person skilled in the art would also be conceivable. The sun protection device 10 has a spectacle frame 22. The spectacle frame 22 is formed by a spectacle frame. The spectacle frame 22 is essentially made of plastic. In principle, however, another material that would appear appropriate to a person skilled in the art would also be conceivable. The spectacle frame 22 has a base frame 26 and two spectacle temples 28 movably mounted on the base frame 26, only one of which is visible. The base frame 26 has a nose cutout 30 for resting on a nose 31 of a user.The temples 28 are each designed to rest on the ears of the user 31.

[0028] The sun protection device 10 further comprises an optical sun protection filter 12. The spectacle frame 22 is provided for receiving the optical sun protection filter 12. The optical sun protection filter 12 is received in the spectacle frame 22. The light transmittance of the optical sun protection filter 12 is adjustable. The optical sun protection filter 12 is substantially transparent, with a transmission T of the optical sun protection filter 12 being electrically variable. The optical sun protection filter 12 has two liquid crystal cells 14, 14'. The liquid crystal cells 14, 14' are mirror-symmetrical to one another. The liquid crystal cells 14, 14' are received in the spectacle frame 22. The base frame 26 of the spectacle frame 22 has two recesses in which the liquid crystal cells 14, 14' are received.The liquid crystal cells 14, 14' are each arranged on opposite sides of the nose cutout 30. Each of the liquid crystal cells 14, 14' of the optical sun protection filter 12 is assigned to a respective eye of the user 31. The liquid crystal cells 14, 14' each have a liquid crystal plane 32 whose transmission T can be switched.

[0029] The liquid crystal cells 14, 14' of the optical sun protection filter 12 are each formed from a plastic liquid crystal cell. The liquid crystal cells 14, 14' each consist of several layers. The number of layers is merely exemplary and can vary fundamentally. The liquid crystal cells 14, 14' are each formed from a TN liquid crystal cell. The liquid crystal cells 14, 14' are therefore based on twisted nematic technology.In principle, however, other designs of the liquid crystal cells 14, 14' that would appear appropriate 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. The liquid crystal cells 14, 14' each have a liquid crystal plane 32. The liquid crystal plane 32 is formed by a translucent liquid crystal plane. The liquid crystal plane 32 has a liquid crystal layer 34.The liquid crystal layer 34 contains a multitude of crystal molecules and spacers. A polyimide layer 35, 35' is arranged on each side of the liquid crystal layer 34. The polyimide layers 35, 35' serve in particular to align the crystal molecules. An electrode layer 36, 36' is arranged on each side of the polyimide layers 35, 35' facing away from the liquid crystal layer 34. The electrode layers 36, 36' are each formed from a transparent indium tin oxide layer. Furthermore, a polarization layer 37, 37' is arranged on each side of the liquid crystal plane 32 of the liquid crystal cells 14, 14'. The polarization layers 37, 37' each serve to polarize incident light. A disk 38, 38' is arranged on each side of the polarization layers 37, 37' facing away from the liquid crystal plane 32. The discs 38, 38' are made of plastic.The panes 38, 38' are made of polycarbonate. An anti-reflection layer 39, 39' and a hard layer 40, 40' are applied to an outer side of each of the panes 38a, 38a'. The liquid crystal cells 14, 14' of the optical sun protection filter 12 are each at least partially curved. The liquid crystal cells 14, 14' of the optical sun protection filter 12 are each curved over their entire extent (. Fig. 4 ).

[0030] Figure 5shows the sun protection device 10 and the user 31 with different viewing angles of the user 31 viewed in a horizontal plane. A first viewing angle of the user 31 to a first point 60 is shown. The first point 60 lies in an edge region of the field of vision of the user 31. A viewing direction 62 of the first eye 43 of the user 31 to the first point 60 falls through the curved liquid crystal cell 14 at an angle of 83°. A viewing direction 62' of the second eye 43' of the user 31 to the first point 60 falls through the curved liquid crystal cell 14' at an angle of 126°. A difference between the two viewing directions 62, 62' of the two eyes 43, 43' of the user 31 is therefore 43°. With the same arrangement, the difference would be approximately 63° with straight liquid crystal cells. Furthermore, a second viewing angle of the user 31 to a second point 64 is shown.The second point 64 lies in a center of the field of vision of the user 31. A viewing direction 66 of the first eye 43 of the user 31 to the second point 64 falls through the curved liquid crystal cell 14 at an angle of 103°. A viewing direction 66' of the second eye 43' of the user 31 to the second point 64 falls through the curved liquid crystal cell 14' at an angle of 107°. A difference between the two viewing directions 66, 66' of the two eyes 43, 43' of the user 31 is therefore 4°. With the same arrangement, the difference would also be approximately 4° for straight liquid crystal cells. The curved design of the liquid crystal cells 14, 14' therefore makes it possible to produce an advantageously uniform image, particularly in the edge regions of the field of vision of the user 31. In particular, disturbing differences between the two eyes 43, 43' of the user 31 can be achieved.

[0031] Furthermore, the sun protection device 10 has a sensor unit 16. The sensor unit 16 is provided for detecting solar radiation. The sensor unit 16 is arranged in the spectacle frame 22. The sensor unit 16 is arranged in the base frame 26 of the spectacle frame 22 between the recesses for the liquid crystal cells 14, 14'. The sensor unit 16 is arranged in the base frame 26 of the spectacle frame 22 above the nose cutout 30. The sensor unit 16 is uncovered towards a front side of the sun protection device 10. The sensor unit 16 has a photodiode 24. The sensor unit 16 has a photocell. In principle, however, it would also be conceivable for the sensor unit 16 to have a solar cell. The sensor unit 16 has a photodiode 24 formed by a photocell. The sensor unit 16 is formed by the photodiode 24.

[0032] Furthermore, the sun protection device 10 has a control and regulation unit 18. The control and regulation unit 18 is provided for controlling the transmittance of the optical sun protection filter 12 depending on solar radiation. For this purpose, the control and regulation unit 18 is connected to the sensor unit 16 in a manner not further visibly. Furthermore, the control and regulation unit 18 is connected to the liquid crystal cells 14, 14' of the optical sun protection filter 12 in a manner not further visibly. The control and regulation unit 18 is electrically connected to the electrode layers 36, 36' of the liquid crystal cells 14, 14' in a manner not further visibly. The control and regulation unit 18 is arranged in the spectacle frame 22. The control and regulation unit 18 is arranged in the base frame 26 of the spectacle frame 22 between the recesses for the liquid crystal cells 14, 14'. The control and regulation unit 18 is arranged in the base frame 26 of the spectacle frame 22 above the nose cutout 30.In principle, however, another arrangement of the control and regulation unit 18 that would appear sensible to a person skilled in the art would also be conceivable. The control and regulation unit 18 is constantly in operation and, in particular, cannot be deactivated. The control and regulation unit 18 switches on when a defined voltage is applied to the sensor unit 16 and begins to oscillate. In principle, however, it would also be conceivable for the control and regulation unit 18 to be activated by means of a switch that is not visible.

[0033] In an operating state, the control and regulating unit 18 is provided to control the liquid crystal cells 14, 14' of the optical sun protection filter 12 to generate a transmittance profile 20 defined for a user 31 with at least two different transmittances. During solar radiation, the control and regulating unit 18 is provided to control the liquid crystal cells 14, 14' of the optical sun protection filter 12 to generate a transmittance profile 20 defined from a viewing direction of the user 31 with at least two different transmittances. During solar radiation, the control and regulating unit 18 is provided to control the liquid crystal cells 14, 14' of the optical sun protection filter 12 to generate a continuous transmittance profile 20 defined from a viewing direction of the user 31 with at least two different transmittances.In the transmittance profile 20, a lower transmittance of the liquid crystal cells 14, 14' of the optical sun protection filter 12 is arranged above a higher transmittance for a user 31. The transmittance profile 20 therefore extends from top to bottom for a user 31, with transmittance increasing from top to bottom. Furthermore, the transmittance profile 20 extends from a viewing direction of the user 31 parallel to a main extension plane 42 of the respective liquid crystal cell 14, 14'. The main extension plane 42 of the liquid crystal cells 14, 14' forms an angle of 12° with respect to a vertical 41 when the user 21 is in an upright position. In an operating state, the control and regulation unit 18 is provided to control the liquid crystal cells 14, 14' of the optical sun protection filter 12 to maintain the transmittance profile 20 defined for a user 31.The control and regulation unit 18 is provided to control the liquid crystal cells 14, 14' of the optical sun protection filter 12, with constant solar radiation relative to the sun protection device 10a, to maintain the transmittance profile 20 defined from a viewing direction of the user 31. Furthermore, the control and regulation unit 18 is provided in an operating state to adjust the strength and extent of the transmittance profile 20 of the liquid crystal cells 14, 14' of the optical sun protection filter 12 for a user 31 depending on the solar radiation.The control and regulation unit 18 is provided for adjusting the extent of the transmittance curve 20 of the liquid crystal cells 14, 14' of the optical sun protection filter 12 from a viewing direction of the user 31 depending on solar radiation, thereby changing the average transmittance across the surface of the liquid crystal cells 14, 14'. As the solar radiation increases, the average transmittance across the surface of the liquid crystal cells 14, 14' decreases from a viewing direction of the user 31. In addition, the control and regulation unit 18 is provided for adjusting the extent of the transmittance curve 20 of the liquid crystal cells 14, 14' of the optical sun protection filter 12 for the user 31 depending on a user input.The control and regulation unit 18 is designed to adjust the strength and extent of the transmittance curve 20 of the liquid crystal cells 14, 14' of the optical sun protection filter 12 for the user 31, depending on a user-adjustable level for adjusting the transmittance curve 20. The user-adjustable level is entered via a non-visible input unit. The user-adjustable level defines a correction factor for the transmittance curve 20 defined for the user relative to the solar radiation. From the viewing direction of the user 31, the transmittance curve 20 extends ever further from top to bottom into the liquid crystal cells 14, 14' as the solar radiation increases.The transmittance curve 20 is visible to a user 31 when the sun protection device 10 is worn and is generated by the optical properties of the liquid crystals of the liquid crystal cells 14, 14' themselves. The defined transmittance curve 20 arises from the angle dependence of the liquid crystal cells 14, 14', i.e., an influence on the transmission of the liquid crystal cells 14, 14' depending on the viewing angle of the eyes 43, 43' of the user 31 to the crystal molecules of the liquid crystal layer 34, as well as depending on the orientation of the crystal molecules. With increasing angle of the viewing direction or the viewing angle relative to the crystal molecules of the liquid crystal layer 34 of the liquid crystal cell 14, 14', the transmission of the liquid crystal cell decreases and absorption increases.

[0034] Figure 6shows the sun protection device 10 and the user 31 with different viewing angles of the user 31 viewed through the liquid crystal cell 14' in a vertical plane. A first viewing angle of the user 31 with a first viewing direction 68 is shown. The first viewing direction 68 passes through the liquid crystal cell 14' in an upper region of the liquid crystal cell 14'. The first viewing direction 68 passes through the liquid crystal cell 14' at a first viewing angle 70. The first viewing angle 70 is approximately 123°. Furthermore, a second viewing angle of the user 31 with a second viewing direction 68' is shown. The second viewing direction 68' passes through the liquid crystal cell 14' below the first viewing direction 68 in a central region of the liquid crystal cell 14'. The second viewing direction 68' passes through the liquid crystal cell 14' at a second viewing angle 70'. The second viewing angle 70' is approximately 90°.Furthermore, a third viewing angle of the user 31 is shown with a third viewing direction 68". The third viewing direction 68" falls below the second viewing direction 68' in a central region of the liquid crystal cell 14' through the liquid crystal cell 14'. The third viewing direction 68" falls through the liquid crystal cell 14 at a third viewing angle 70". The third viewing angle 70" is approximately 77°. In addition, a fourth viewing angle of the user 31 is shown with a fourth viewing direction 68‴. The fourth viewing direction 68‴ falls below the third viewing direction 68" in a lower region of the liquid crystal cell 14' through the liquid crystal cell 14'. The fourth viewing direction 68‴ falls through the liquid crystal cell 14 at a fourth viewing angle 70‴. The fourth viewing angle 70‴ is approximately 55°. As the gaze is lowered, the viewing angle of the user 31 through the liquid crystal cell 14' also decreases.Due to the viewing angle dependence of the liquid crystal cells 14, 14', the transmission of the liquid crystal cell increases, and absorption is reduced, at least during operation, with decreasing angles of the viewing direction or viewing angle relative to the crystal molecules of the liquid crystal layer 34 of the liquid crystal cells 14, 14'. Therefore, during operation of the sun protection device 10, the transmission of the fourth viewing direction 68‴ of the user 31 is significantly higher than the transmission of the first viewing direction 68 of the user 31. This creates a defined transmittance profile 20 for the user 31.

[0035] In an operating state, the control and regulation unit 18 is provided to control a drive voltage VA for driving the liquid crystal cells 14, 14' of the optical sun protection filter 12 to a value below a saturation field strength of the liquid crystal cells 14, 14'. To generate the transmittance curve 20, the control and regulation unit 18 is provided to control a drive voltage VA for driving the liquid crystal cells 14, 14' of the optical sun protection filter 12 to a value below a saturation voltage VS required to provide a saturation field strength of the liquid crystal cells 14, 14'. The saturation voltage VS for providing a saturation field strength of the liquid crystal cells 14, 14' forms a saturation voltage.The liquid crystal cells 14, 14' of the optical sun protection filter 12 are generally driven with a drive voltage VA that is lower than the saturation voltage VS. With increasing solar radiation, the drive voltage VA is increased. The drive voltage VA is the voltage applied to the electrode layers 36, 36' of the liquid crystal cells 14, 14' to generate an electric field for aligning the liquid crystal layer 43 of the liquid crystal cells 14, 14'. Upon application of a drive voltage VA that is below a saturation voltage VS required to provide the saturation field strength of the liquid crystal cells 14, 14', the crystal molecules of the liquid crystal layer 43 of the liquid crystal cells 14, 14' are only partially deflected, so that a viewing angle dependence of the liquid crystal cells 14, 14' occurs.For the user 31, the transmittance curve 20 is created in the liquid crystal cells 14, 14'.

[0036] Figure 7 shows a diagram of a transmission T of the liquid crystal cells 14, 14' of the sun protection filter 12 as a function of a control voltage VA . The transmission T is plotted on a vertical y-axis, with the control voltage VA being plotted on the horizontal x-axis. The diagram represents the average transmission T of the liquid crystal cells 14, 14' over the area in percent as a function of a control voltage VA. The diagram also shows the saturation voltage VS. For control voltages VA that are greater than zero and less than the saturation voltage VS, a transmittance curve 20 is present from the user's viewing direction.

[0037] In the Figures 8A, 8B, 8C and 8D Four different states of the sun protection device 10 are shown as examples. Figures 8A, 8B, 8C and 8Dshow the transmittance curve 20 of the liquid crystal cells 14, 14' of the optical sun protection filter 12 in the respective states, wherein in the diagram the Figure 4 The corresponding control voltage VA , which is applied to the electrode layers 36, 36' of the liquid crystal cells 14, 14' in the corresponding state, is shown. The control voltage V A1 is assigned to the first state, which is in the Figure 8A The control voltage V A2 is assigned to the second state, which is shown in the Figure 8B The control voltage V A3 is assigned to the third state, which is shown in the Figure 8C The control voltage V A4 is assigned to the fourth state, which is shown in the Figure 8Dis shown. In the first state, solar irradiation is low compared to the other states. In the fourth state, solar irradiation is high compared to the other states. The control voltage VA increases with increasing solar irradiation.

[0038] In an operating state, the sensor unit 16 is provided for at least partially providing energy to control the liquid crystal cells 14, 14' of the optical sun protection filter 12. During operation of the sun protection device 10, the sensor unit 16 is provided for completely providing energy to control the liquid crystal cells 14, 14' of the optical sun protection filter 12. During operation of the sun protection device 10, the sensor unit 16 is provided for completely obtaining the energy required to control the at least one liquid crystal cell 14, 14' of the optical sun protection filter 12. The sensor unit 16 provides the control voltage VA. Furthermore, the sun protection device 10 is therefore designed to be battery-free.

[0039] Figure 9shows a flowchart of a method for operating a sun protection device 10. In the method, liquid crystal cells 14, 14' of the optical sun protection filter 12 are controlled to generate a transmittance profile 20 defined for the user. The liquid crystal cells 14, 14' of the optical sun protection filter 12 are controlled to generate a transmittance profile 20 defined for the user depending on solar radiation. Solar radiation is detected by the sensor unit 16 in a step 44. Subsequently, a value of the voltage generated by the sensor unit 16 is monitored in a branch 46. If a threshold value is not exceeded, step 44 is repeated.If the value of the voltage generated by the sensor unit 16 exceeds a certain value, an oscillation in the magnitude of the sensor voltage is generated in a further step 48 by means of an astable flip-flop 50, so that the alternating voltages for controlling the liquid crystal cells 14, 14' can be generated by a downstream NAND gate 52. In addition, the liquid crystal cells 14, 14' of the optical sun protection filter 12 are controlled to generate the transmittance curve 20 defined for the user depending on a user input. The liquid crystal cells 14, 14' of the optical sun protection filter 12 are controlled to generate the transmittance curve 20 defined for the user depending on a user-adjustable level for adjusting the transmittance curve.

[0040] Figure 10shows a schematic circuit diagram of the control and regulation unit 18. The sensor unit 16 is arranged on an input side 54 of the control and regulation unit 18. The electrode layers 36, 36' of the liquid crystal cells 14, 14' are arranged on the two output sides 56, 58 of the control and regulation unit 18.

Claims

1. Sun protection device, in particular sun spectacles, with at least one optical sun protection filter (12) comprising at least one liquid-crystal cell (14, 14'), with at least one sensor unit (16) configured for capturing a solar irradiation, and with at least one control and / or regulation unit (18) configured for controlling and / or regulating a permeability of the optical sun protection filter (12) depending on a solar irradiation, wherein the control and / or regulation unit (18) is in at least one operating state configured for actuating the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) for generating a permeability gradient (20) which is defined for a user (31) and features at least two differing permeabilities, wherein the optical sun protection filter (12) comprises two liquid-crystal cells (14, 14') which are respectively allocated to an eye of the user (31), or comprises only one liquid-crystal cell (14, 14') for both eyes of the user (31), wherein the at least one liquid-crystal cell (14, 14') has a liquid-crystal plane (32) that is switchable in the transmittance T, wherein the defined permeability gradient (20) is a progression of a permeability of the liquid-crystal cell (14, 14') which is visible from a viewing direction of the user (31), in particular the wearer, and which features at least two differing permeabilities at a fix point in time, wherein the defined permeability gradient (20) results from the angle-dependency of the liquid-crystal cell (14, 14'), i.e. an influence on the transmittance of the liquid-crystal cell (14, 14') depending on a viewing angle of the eye of the user (31) onto the crystal molecules and depending on the orientation of the crystal molecules, wherein with increasing lowering of the vision a look-through angle of the user (31) through the liquid-crystal cell (14, 14') is also lowered, wherein with decreasing angling of the viewing direction, respectively the viewing angle, with respect to the crystal molecules of the liquid-crystal layer (34) of the liquid-crystal cell (14, 14'), the transmittance of the liquid-crystal cell (14, 14') increases and absorption is reduced, wherein the angle-dependency of the liquid-crystal cell (14, 14') occurs as a result of applying an actuation voltage (VA), which is controlled by the control and regulation unit (18) and is below a saturation voltage (VS) required for supplying the saturation field strength of the liquid-crystal cells (14, 14'), such that the crystal molecules of a liquid-crystal layer (34) of the liquid-crystal cells (14, 14') are only partly deflected, and wherein the control and / or regulation unit (18) is in at least one operating state configured for actuating the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) for maintaining the permeability gradient (20) which is defined for the user (31), i. e. for maintaining the permeability gradient which is present at a point in time and is defined from a viewing direction of the user (31), over an infinite period, wherein on both sides of the liquid-crystal layer (34) respectively one polyimide layer (35, 35') is arranged, wherein on the sides of the polyimide layers (35, 35') facing away from the liquid crystal layer (34), respectively one electrode layer (36, 36') is arranged, the actuation voltage (VA) being the voltage which is applied to the electrode layers (36, 36') of the liquid-crystal cells (14, 14') for the purpose of generating an electrical field for aligning the liquid-crystal layer (34) of the liquid-crystal cells (14, 14'), wherein the control and / or regulation unit (18) is configured, in at least one operating state, for adjusting, depending on a solar irradiation, an intensity and / or extension of the permeability gradient (20) of the liquid-crystal cells (14, 14') of the optical sun protection filter (12) for the user (31), wherein the control and / or regulation unit (18) is configured, in at least one operating state, for adjusting, depending on a solar irradiation, an extension of the permeability gradient (20) of the liquid-crystal cells (14, 14') of the optical sun protection filter (12) from a viewing direction of the user (31), thus changing for a user an average permeability over the area of the liquid-crystal cells (14, 14'), wherein during operation of the sun protection device, the at least one sensor unit (16) is configured to completely supply an energy for actuating the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12), characterized in that the sun protection device is embodied battery-free.

2. Sun protection device according to claim 1, characterized in that for the user (31) a lower permeability of the at least one liquid-crystal cell (14, 14') is arranged below a higher permeability in the permeability gradient (20).

3. Sun protection device according to one of the preceding claims, characterized in that the control and / or regulation unit (18) is in at least one operating state configured for actuating and / or regulating an actuation voltage (VA), for controlling the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12), to a value below a saturation field strength of the at least one liquid-crystal cell (14, 14').

4. Sun protection device according to one of the preceding claims, characterized in that the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is embodied at least partly curved.

5. Sun protection device according to one of the preceding claims, characterized in that the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is implemented by a plastic liquid-crystal cell.

6. Sun protection device according to one of the preceding claims, characterized by a spectacle frame (22) which is configured for accommodating the optical sun protection filter (12).

7. Sun protection device according to one of the preceding claims, characterized in that the at least one sensor unit (16) is in at least one operating state configured for at least partly supplying an energy for an actuation of the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12).

8. Sun protection device according to one of the preceding claims, characterized in that the at least one sensor unit (16) comprises at least one photodiode (24).

9. Method for operating a sun protection device (10) according to one of the preceding claims.

10. Method according to claim 9, characterized in that the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is actuated and / or regulated for generating a permeability gradient (20) defined for a user (31).

11. Method according to claim 9 or 10, characterized in that the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is actuated and / or regulated depending on a solar irradiation for generating a permeability gradient (20) defined for a user (31).

12. Method according to one of claims 9 to 11, characterized in that the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is actuated and / or regulated, depending on at least one user input, for generating a permeability gradient (20) defined for a user (31).

13. Method according to claim 15, characterized in that for the purpose of generating a permeability gradient (20) defined for a user (31), the at least one liquid-crystal cell (14, 14') of the optical sun protection filter (12) is actuated and / or regulated depending on a user-adjustable level for adapting the permeability gradient (20), wherein the level is selectable via an input unit.