Electro-optical radiation protection device

Abstract

The invention relates to an electro-optical radiation protection device (1), in particular a light protection device, comprising at least one electro-optical protective sheet (1), which covers at least the visual field of one eye and comprises at least one liquid crystal element (2); at least two radiation sensors (3, 4, 5), each of which generates a control signal depending on the intensity of the incident radiation; and control electronics (6), which is designed to receive the control signals and to activate the or each liquid crystal cell (2), and which controls the degree of transmission (T) of the protective sheet (1) as a function of the control signals from the radiation sensors. The radiation sensors (3, 4, 5) are in the form of photodiodes having the highest sensitivity in the infrared range; the sensor surfaces (7, 8, 9) define sensor planes (SE3, SE4, SE5); at least two of the sensor planes (SE3, SE4) intersect one another at an angle of less than 45°; and the intersection line of these sensor planes (SE3, SE4) is preferably in, or parallel to, the sagittal plane (S) of the protective sheet (1).

Description

[0001] ELECTRO-OPTICAL RADIATION PROTECTION DEVICE

[0002] The invention relates to an electro-optical radiation protection device, in particular a light protection device, according to the preamble of claim 1.

[0003] It is known to provide an electro-optical protective screen that covers at least the field of vision of one eye and comprises at least one liquid crystal element. It is also known to provide radiation sensors and to generate a control signal depending on the intensity of the incident radiation, and then to control the transmittance of the protective screen. For example, US Pat. No. 8,081,262 B1 discloses a sun protection device, in particular sunglasses, with at least one optical sun protection filter having at least one liquid crystal cell and with at least one sensor unit designed to detect solar radiation.

[0004] Furthermore, EP 3 258 306 B describes a sun protection device, in particular sunglasses, with at least one optical sun protection filter having at least one liquid crystal cell, and with at least one sensor unit provided for detecting solar radiation. Preferably, the sun protection device also has a control and / or regulating unit provided for controlling and / or regulating a transmittance of the optical sun protection filter depending on solar radiation. A sensor surface of the at least one sensor unit is at least partially covered by at least one sensor cover, which is at least partially at least substantially opaque to radiation of a visible light spectrum.

[0005] EP 3 223 067 A also discloses a sun protection device as explained above, comprising at least one control and / or regulating unit designed to control and / or regulate the transmittance of the optical sun protection filter depending on solar radiation. In at least one operating state, the control and / or regulating unit is designed to control and / or regulate the at least one liquid crystal cell of the optical sun protection filter to generate a defined transmittance profile with at least two different transmittances.

[0006] US Pat. No. 5,552,841 A discloses spectacles with electronically dimmable lenses via liquid crystal cells, which darken depending on the incident radiation. Power is supplied via a film applied to the lenses. Furthermore, a rechargeable battery can be provided, and a dedicated dimming control unit with a manual adjustment knob can be arranged between the solar cell and the lens. One embodiment of these spectacles provides at least one infrared sensor, the output signal of which is used to control the dimming. The dimming can extend across the height of the lens and, if necessary, can also be manually adjustable.

[0007] US 2023 / 0213787 A1 discloses a spectacle device having an ophthalmic lens with variable transmission, a method for controlling the transmission of such a lens, and a computer-readable storage medium for implementing such a method. The spectacle device comprises a light sensor configured to measure an amount of light in the environment of a wearer, and a control circuit configured to receive at least light data from the light sensor and to control the transmission of the ophthalmic lens based on the light. The control circuit is configured to control the transmission of the ophthalmic lens based on further movement data, wherein the movement data is derived from an estimate of a movement of the wearer's head.

[0008] US 2010253603 A1 discloses several embodiments of an electro-optical radiation protection device, in particular a light protection device, for example in the form of a helmet, glasses, or sports goggles. At least one electro-optical protective screen with a liquid crystal element and several radiation sensors is controllable in its transparency depending on the intensity of the incident radiation. Simple control electronics are designed to control the liquid crystal cell and regulate the transmittance of the protective screen. The radiation sensors in the form of photovoltaic cells, which also provide the energy supply, are arranged along the upper edge of the protective screen of a helmet or a lens of sunglasses, which has a curvature. DE 19714434 A1 also proposes using the radiation sensors additionally for the energy supply.

[0009] US Pat. No. 5,671,035 A and DE 19714434 A1 describe glasses in which irradiation above a definable limit, for example, an average value across all raster elements, and from specific directions can be selectively reduced using a raster of dimming elements. Grids of sensors are also provided to determine the direction of irradiation. EP 4238621 A2 also discloses using the sensor value that detects the brightness in the direction of the eye's gaze to control the dimming.

[0010] According to EP 2638427 B1, a differential signal is used to control the liquid crystal cells, with the differential signal being compared with a threshold value. Furthermore, the possibility of using radiation sensors with different detection angles (one detection angle should be smaller, the other larger than 45°) is described, with the different detection ranges overlapping in places.

[0011] The object of the present invention was to improve a device as described above in such a way that the radiation protection is better adapted to the actual lighting conditions in the entire environment of the device and that a reliable operation of the device over a long period of time is ensured with a compact design and light weight.

[0012] This object is achieved by a device according to the claims.

[0013] To achieve this object, the device according to the invention is characterized in that the radiation sensors are designed as photodiodes with a sensitivity range between 400 and 1100 nm and preferably the highest sensitivity in the near infrared, in particular between 800 nm and 900 nm, wherein the sensor surfaces define sensor planes which enclose an angle of less than 45° with the vertical axis of symmetry of the protective screen, wherein at least two of the sensor planes intersect each other at an angle of less than 45°, and wherein the intersection line of these sensor planes preferably lies in or parallel to the sagittal plane of the protective screen. Thus, the lighting conditions in a larger area in the horizontal plane around the protective device can be used to control the transmittance and thus for the necessary protection factor.

[0014] Preferably, at least three radiation sensors are provided per protective pane, wherein the sensor surface of the middle radiation sensor is oriented parallel to the transverse axis of the protective pane, and wherein the sensor planes of at least one radiation sensor arranged laterally on either side of the middle radiation sensor, preferably of the immediately adjacent radiation sensor, intersect the sensor plane of the middle radiation sensor at an angle of less than 45°. This allows an even larger area around the protective device to be used for controlling the transmittance and thus for the necessary protection factor. A further preferred embodiment provides four sensors per protective pane, preferably arranged in a horizontal row, wherein the sensor surfaces of the two middle sensors can either intersect at an angle of less than 45° or be aligned parallel to one another.

[0015] A further embodiment of the invention is characterized in that the sensor planes enclose an angle between 1° and 33°, preferably between 3° and 25°. These values ​​ensure that the half-angles of the radiation sensors do not diverge too much, thus ensuring that the signal strength always remains sufficiently high, regardless of the direction of the radiation.

[0016] Furthermore, it is advantageously provided that at least one of the sensor planes forms an angle of less than 45° with the transverse axis of the protective screen. This allows an even larger area around the protective device to be used for controlling the transmittance, namely also in a larger angular range in the sagittal plane.

[0017] Preferably, the photodiodes intended as radiation sensors are operated in photovoltaic mode, with the output voltage being fed into the control electronics as a control signal and preferably also used to power the control electronics and / or the liquid crystal cell. This avoids the need for additional power sources such as batteries, accumulators, etc., and saves both weight and space.

[0018] In this case, an embodiment is particularly advantageous in which a photodiode and / or a photovoltaic element is connected to the control electronics and / or the liquid crystal cell as an energy supply for the latter. In this embodiment, devices with higher energy requirements can also be operated without separate energy sources such as batteries or rechargeable batteries and can therefore be kept light and small. According to a further feature of the invention, the control electronics are designed in such a way that they determine an average value from the signals of all light sensors and control the transmittance of the liquid crystal cell depending on this average value. This ensures that even in the event of a relative movement of the light source, in particular around the vertical axis of the protective device, darkening that is as uniform as possible across the surface of the protective screen and that also remains constant over time.

[0019] According to a further embodiment of the invention, the radiation protection device is characterized in that the control electronics are designed to control the transmittance of the liquid crystal cell depending on the respective highest control signal from all light sensors. This makes it possible to adjust the dimming for the highest possible protection of the wearer of the protective device.

[0020] A further embodiment of the invention is characterized in that at least one of the radiation sensors is arranged on the side of the protective screen opposite the liquid crystal element. This prevents impairments in the detection of the incident light caused by optical deflections and / or mirroring.

[0021] A further preferred embodiment is one in which the radiation sensors and preferably the control electronics are integrated into the protective screen or mounted thereon, preferably in the region of the upper edge and preferably in or near the sagittal plane. This offers high flexibility for the use of the protective screen in various support arrangements, for example, with support frames of different designs, from different manufacturers, etc.

[0022] A further embodiment of the radiation protection device is characterized in that each radiation sensor is assigned a liquid crystal cell, wherein the transmittance of the protective screen in the area of ​​each liquid crystal cell is individually controlled depending on the incidence of light determined by the assigned radiation sensor. This combination of features allows the protective effect, i.e. the darkening, to be precisely adjusted to the direction of incidence of the radiation, while the other viewing angle ranges are not darkened or are only slightly darkened and optimal visibility conditions are maintained. Yet another embodiment of the radiation protection device provides that the protective screen is brightened in the activated state and darkened in the deactivated state. This makes it possible to reduce or avoid the energy consumption in the deactivated state.

[0023] To enable the radiation protection device according to the invention to be worn like eyeglasses, in particular as sunglasses or sports glasses, it comprises a support frame and at least one protective screen mounted on or in a support frame or interchangeably connected thereto. These protective screens cover at least a large part of the field of vision of at least one eye.

[0024] To achieve the object of the invention, such a protective device, in particular goggles, is characterized in that at least one of the radiation sensors, preferably all of the radiation sensors, and preferably also the control electronics are integrated into the protective screen or attached thereto, preferably near the upper edge of the protective screen. This offers high flexibility for the use of the protective screen in various support arrangements, for example, with support frames of different designs, from different manufacturers, etc.

[0025] Alternatively, such a radiation protection device with a support frame can also be characterized in that at least some of the radiation sensors, preferably all of the radiation sensors, and the control electronics are integrated into the support frame or mounted thereon, preferably near the upper edge of the protective screen and in or near the sagittal plane of the support frame. This results in no restrictions of the field of view in the area of ​​the protective screen, and all necessary components can be positioned at the optimal location across the entire area of ​​the support frame, depending on their structural design.

[0026] A preferred embodiment is one in which a photodiode and / or a photovoltaic element is connected to the control electronics and / or the liquid crystal cell as a power supply and is preferably integrated in the support frame or attached to the support frame. This makes it possible to improve the power supply, since components optimally designed for the radiation spectrum can be used independently of the photodiodes provided for controlling the radiation protection. A further embodiment of the invention is characterized in that two protective screens are mounted on or in a support frame or are interchangeably connected to it, wherein the protective screens are arranged in such a way as to each cover at least a large part of the field of vision of one eye. The device according to the invention is thus in the form of conventional glasses that are simple and comfortable to wear.

[0027] Yet another embodiment of the radiation protection device provides that the support frame completely encloses both protective screens along their edges and has a nose recess in the area of ​​the sagittal plane or the central axis forming an axis of symmetry. This recess extends from the lower edge and extends over part of the height of the protective screens toward the upper edge of the support frame. This provides optimal protection for the protective screens against accidental detachment from the support frame and against mechanical damage to these high-quality components, especially their edges.

[0028] According to an alternative embodiment of the invention, a protective screen is mounted on or in a support frame, or is replaceably connected to it, and covers at least a large part of the field of vision of both eyes. This eliminates any restrictions caused by interfering elements, such as frame sections, nose pads, etc., in the field of vision of the wearer of the protective device, ensuring optimal visibility across the entire field of vision.

[0029] Preferably, the protective screen and / or an edge of the support frame enclosing the protective screen in the region of the sagittal plane or the central axis forming an axis of symmetry has / have a nose recess starting from the lower edge and extending over part of the width of the protective screen in the direction of the upper edge of the protective screen in order to ensure wearing comfort and secure positioning equivalent to conventional spectacles.

[0030] In the context of this application, a "radiation protection device" is understood to mean, in particular, a device intended to protect a user's eyes from, in particular, disturbing, light or solar radiation. Preferably, this is understood to mean, in particular, a device intended to at least reduce solar radiation. Particularly preferably, the radiation protection device is intended, in at least one operating state, to darken, in particular, disturbing, light or solar radiation on the user's eyes. Various embodiments of this device that would appear appropriate to a person skilled in the art are conceivable, such as, for example, a shield and / or, particularly preferably, protective goggles.

[0031] Furthermore, in this context, a "sensor surface" of the sensor unit should be understood in particular as a detection surface of the sensor unit. Preferably, this should be understood in particular as a surface of the sensor unit on which the sensor unit can detect radiation, in particular incident light. Particularly preferably, this should be understood in particular as a cell surface of the sensor unit. Preferably, the sensor surface is directed forward or diagonally forward, i.e., in particular in the direction of a hypothetical viewing direction or a larger field of vision of a user. Preferably, the sensor surface extends substantially parallel to an end face of the radiation protection device, in particular tangentially to the surface of a protective screen of the radiation protection device.

[0032] Furthermore, in this context, a "protective screen" is to be understood in particular as a screen made of glass and / or plastic. Its light transmittance is preferably adjustable, possibly with automatic and / or manually adjustable darkening. Particularly preferably, the protective screen has at least one liquid crystal layer with switchable transmission and at least one liquid crystal cell. Various liquid crystal cells are conceivable that would be appropriate to a person skilled in the art, such as, in particular, a TN liquid crystal cell using twisted nematic technology.Furthermore, various radiation sensors that would appear appropriate to a person skilled in the art are conceivable for a radiation protection device according to the application, for example, photocells, in particular photodiodes and / or solar cells, which are preferably designed for at least optical detection of a limited spectral range of the incident radiation and / or artificial light. The sensor surface is preferably directed forward, i.e., in particular, toward a hypothetical line of sight of a user.

[0033] The darkening or modification of the transmission of the protective device should be such that at least 50%, preferably at least 70%, and particularly preferably at least 90% of the corresponding incident radiation is absorbed and / or reflected, at least in the visible light range, i.e., in particular in the wavelength range from 380 nm to 780 nm. "Control electronics" is understood, in particular, to mean 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, through the use of an application-specific integrated circuit (ASIC) and / or a microcontroller module.

[0034] For a better understanding of the invention, it is explained in more detail using the following figures.

[0035] They show in a highly simplified, schematic representation:

[0036] Fig. 1 shows a first embodiment of a protective screen according to the invention with three radiation sensors in front view;

[0037] Fig. 2 the protective screen of Fig. 1 in a view obliquely from above;

[0038] Fig. 3 is a section parallel to the transverse plane in the central area of ​​the protective screen of Fig. 1 and Fig. 2, with the diagrams of the reception characteristics of the radiation sensors;

[0039] Fig. 4 is a diagram of the reception characteristics of the three radiation sensors of the protective screen of Fig. 1 and Fig. 2 and a schematic circuit diagram;

[0040] Fig. 5 shows a section parallel to the sagittal plane through a second embodiment of a protective screen according to the invention;

[0041] Fig. 6 is a perspective view of a first embodiment of a radiation protection device according to the invention in the form of glasses with a protective screen corresponding to Figs. 1 to 4;

[0042] Fig. 7 is a section parallel to the sagittal plane through the radiation protection device of Fig. 6;

[0043] Fig. 8 is a perspective view of a second embodiment of a radiation protection device according to the invention in the form of glasses with two separate protective lenses; Fig. 9 is a diagram of the voltages of the three radiation sensors, the total voltage, and an average value.

[0044] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations, whereby the disclosures contained in the entire description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and if the position changes, these positional information must be applied analogously to the new position. For a better understanding of the structure, some elements may be shown not to scale and / or enlarged and / or reduced in size.

[0045] Fig. 1 shows a protective screen 1 for an electro-optical radiation protection device, in particular for a protection device against excessive light irradiation, for example for use as sun protection, as sports or sunglasses or also for self-darkening optical glasses.

[0046] The protective screen 1 covers at least the field of vision of one of the wearer's eyes and supports the electro-optical element or can itself be designed as an electro-optical element. The protective screen 1 can be made of a suitable plastic, for example, polycarbonate, or glass. The protective screen 1 can itself be provided with a supporting structure, such as temples, elastic bands, etc., to enable use as a standalone radiation protection device.

[0047] The radiation protection device further comprises at least one liquid crystal element 2 with at least one, preferably several, liquid crystal cells 2a, 2b,..., which liquid crystal element 2 can be part of the protective screen 1, as shown in Figs. 1 to 3. However, the protective screen 1 can support the liquid crystal element(s) 2 or their cells 2a, 2b,... and then serves as a carrier for the liquid crystal element 2. The liquid crystal element 2 can be arranged on the protective screen 1 in the direction of the line of sight to an object, on the front or back thereof. When the sun protection device is in use, the front side faces the user of the radiation protection device, while the outer side is on the opposite side facing the object to be viewed. The liquid crystal element 2 can also be attached to the outer side or inner side of a protective screen 1 acting as a carrier.

[0048] A very advantageous embodiment provides the liquid crystal cells of the liquid crystal element 2 in a mirror-symmetrical arrangement with respect to the sagittal plane. A mirror-symmetrical arrangement of liquid crystal cells with respect to a transverse plane also has advantages, for example, in facilitating a different darkening of the protective device depending on the angle of incidence of the radiation relative to the horizontal. The liquid crystal cells each have a liquid crystal plane whose transmission T can be switched. In principle, however, it would also be conceivable for only one liquid crystal cell to be present, which extends, in particular, across the field of vision of both eyes of the user.

[0049] The liquid crystal cells are preferably each formed from a plastic liquid crystal cell. The liquid crystal cells can each consist of several layers and can also follow the shape of the protective screen 1 with regard to both the flat design and any curved shape.

[0050] Furthermore, the protective screen 1 has at least two, but preferably three radiation sensors 3, 4, 5, which are preferably arranged in the region of the upper edge of the protective screen 1 and preferably centrally, i.e. in the region of the sagittal plane S or a vertical axis V through the protective screen 1. The vertical axis runs parallel to or at an acute angle of less than 45° to a height of the protective screen 1. Furthermore, it is advantageous if the radiation sensors 3, 4, 5 are arranged on the protective screen 1 adjacent to the liquid crystal element 2. Preferably, the radiation sensors 3, 4, 5 are located next to one another in a line along or parallel to a transverse axis Q of the protective screen 1, which runs parallel to the width of the protective screen 1.A further embodiment provides four sensors per protective screen 1, preferably arranged in a horizontal row, wherein the sensor surfaces of the two middle sensors can either intersect at an angle of less than 45° or can also be aligned parallel to one another.

[0051] Furthermore, Fig. 1 shows the frontal plane F, to which the transverse axis runs parallel and which runs parallel to a plane that is tangent to the protective screen 1 of Fig. 1 to Fig. 6 in its central region. Each of the radiation sensors 3, 4, 5 generates a control signal depending on the intensity of the incident radiation and is connected to control electronics 6 (Figs. 2 and 3) designed to receive the control signals and to control the liquid crystal element 2 or the or each liquid crystal cell 2a, 2b, .... in order to control their transmittance and thus also the transmittance of the radiation protection device as a function of the control signals of the radiation sensors 3, 4, 5 and thus also as a function of the radiation intensity.

[0052] The radiation sensors 3, 4, 5 are preferably designed as photodiodes, whose highest sensitivity is preferably in the near infrared range. The range with the highest sensitivity, in which the radiation sensors 3, 4, 5, preferably operated in photovoltaic mode, deliver the highest current or the highest voltage, is preferably between 800 and 900 nm, with the entire spectral sensitivity range preferably being between 400 and 1100 nm. Between 50% and 75%, preferably between 65% and 70%, of the energy from the radiation sensors or photodiodes thus originates from the infrared region of the spectrum. All sensors are preferably connected in series.

[0053] Thus, the output voltage or output current can be fed into the control electronics 6 as a control signal, as well as used to supply power to the control electronics 6 and / or the liquid crystal element 2 or the liquid crystal cell 2a, 2b, etc. Should more power be required to operate the control electronics 6 and / or the liquid crystal cells 2, an additional photodiode 10 and / or a photovoltaic element 11 could be provided to support or entirely assume the power supply for the control electronics 6 and / or the liquid crystal cells.

[0054] The sensor surfaces 7, 8, 9 of the radiation sensors 3, 4, 5 define or lie in sensor planes SE3, SE4 and SE5, which in the embodiment of Fig. 1 to Fig. 4 are aligned normal to the transverse plane T or parallel to the vertical axis V. The sensor surfaces 7, 8, 9 of the radiation sensors 3, 4, 5 can be arranged in different spatial relative positions to one another.

[0055] If the sensor surfaces 7, 8, 9 of the radiation sensors 3, 4, 5 are located, for example, in the same frontal plane F, as schematically illustrated in Fig. 9, the radiation sensors 3, 4, 5 are designed and positioned relative to one another such that the lobes of the horizontal reception characteristics overlap in the edge regions. This allows for improved detection of the light intensity of the incident infrared radiation and improved averaging of the sum signal of the radiation sensors 3, 4, 5. In the case of obliquely incident radiation, an improved shading relationship between the incident light radiation at different angular positions relative to the frontal plane F can be achieved.

[0056] The control electronics 6 are preferably designed to determine an average value from the signals of all radiation sensors 3, 4 or 4, 5 or all existing radiation sensors and to control the transmittance of the liquid crystal element 2 depending on this average value. This also attracts obliquely incident radiation in order to form an average value of the intensity of the radiation striking the protective screen 1. By overlapping the sensor ranges of the individual radiation sensors and in conjunction with the evaluation of the infrared radiation, an attenuation of the signal change is achieved compared to using the incident visible light radiation, and a more harmonious adjustment of the darkening is achieved depending on the angle of incidence and change in light intensity.Above all, this makes it possible for the radiation protection device to be darkened somewhat less over the entire surface of the protective screen 1 in order to provide sufficient visibility for the user even in those areas where a lower light intensity occurs on the radiation protection device 1.

[0057] In a further possible independent embodiment of the invention, the sensor surfaces 7, 8, 9 of the radiation sensors 3, 4, 5 can define sensor planes SE3 and / or SE4 and / or SE5 or lie in these, as is shown in the embodiment of Fig. 1 to 4. The sensor planes SE3 and / or SE4 and / or SE5 are aligned normal to the transverse plane T or parallel to the vertical axis V, ie their surface normals each lie in the transverse plane T. In the context of the present invention, they form a "curved" arrangement, as will be explained below, wherein the surface normals are not oriented parallel, but enclose acute angles with one another.

[0058] To clarify this feature, the sensor plane SE3 of the radiation sensor 3 is shown in Fig. 2. In the example of Fig. 2, the sensor plane SE4 of the central radiation sensor 4 coincides with the frontal plane F, or will generally be oriented parallel to it. The sensor plane SE4 forms an angle a of less than 45° with the sensor plane SE3. The arrangement of the radiation sensors 3, 4, 5 is preferably symmetrical, and the sensor plane SE5 of the radiation sensor 5 opposite the radiation sensor 3 also intersects the sensor plane SE4 of the central radiation sensor 4 at the same angle a. Preferably, the angle a, or each angle between the sensor planes SE3 and SE4 or SE4 and SE5, is between 1° and 33°, preferably between 3° and 25°. The intersection line of the sensor planes SE3 and SE4 or SE4 and SE5 preferably lies in the sagittal plane S of the protective screen 1 or parallel thereto.

[0059] The sectional view of Fig. 3 shows a section through a protective screen 1 at the level of the sensors 3, 4, 5, i.e. in the upper edge area and centrally in the protective screen 1. In addition to the radiation sensors 3, 4, 5, the aforementioned photodiode 10 and a photovoltaic element 11 are also shown. Furthermore, this illustration in Fig. 3 shows the control electronics 6, which, like the radiation sensors 3, 4, 5, are arranged or molded into or fastened in some other way in an area of ​​the protective screen 1 that is free from the liquid crystal element 2 on the inside I of the protective screen 1. The area free from the liquid crystal element 2 can be seen, among other things, in Figs. 1 and 5. However, the control electronics 6 can also be arranged in a support frame 12 of the glasses, a temple 13 or the frame 14, as is schematically indicated, among other things, in Fig. 8.However, even with protective screens 1 that are assigned to only one eye each, the control electronics 6 can also be arranged on the respective protective screen 1. Furthermore, the symmetrical arrangement of the radiation sensors 3, 4, 5 and their sensor surfaces 7, 8, 9 can be seen. Both the sensor plane SE5 on the left side and the sensor plane SE3 on the right side form an acute angle a of less than 45° with the sensor plane SE4 or a frontal plane F.

[0060] This results in a situation for the reception characteristics of the radiation sensors 3, 4, 5 as also shown in Fig. 3, in which the lobes of the horizontal reception characteristics overlap each other and in which the adjacent lobes are inclined towards each other by the same angle a as between the sensor planes SE3 and SE4 or SE4 and SE5.

[0061] The control electronics 6 is preferably designed to determine an average value from the signals of all radiation sensors 3, 4, 5 and to control the transmittance of the liquid crystal cell 2 depending on this average value. The corresponding voltage diagrams of a preferred embodiment are shown in Fig. 9. On the left-hand side of Fig. 9, the output voltages V3, V4 and V5 of the radiation sensors 3, 4, 5 are plotted one above the other, as they arise when light is incident according to Fig. 4. On the right in Fig. 9, the sum signal VS is shown on the same scale, with the components of the output voltages V3, V4 and V5 identified. Finally, an average signal VM is also shown, here as preferred as a third of the sum signal VS.In the present case, with oblique light incidence, the mean value VM of the three partial signals V3, V4, V5 of sensors 3, 4, 5, which were recorded by the three sensors at the angles depending on the light incidence, is smaller than the signal V3 of the radiation sensor 3, which is most strongly hit by the radiation. This means that obliquely incident radiation is also used to calculate an average value of the intensity of the radiation striking the protective screen 1. As can be better seen in Fig. 4, which only shows the lobes of the reception characteristics, with, for example, oblique light incidence - symbolized in Fig. 4 by the oblique arrows - the radiation sensor more closely facing the light incidence compensates for the strong decrease in sensitivity of the opposite radiation sensor, which is most remote from the light incidence.It is thus possible to create a compensation for the brightness across the entire width of the protective screen 1, so that the areas of the protective screen 1 hit by radiation of lower intensity do not darken as much as if only the energy generated frontally by the incident radiation were used to darken the arrangement of the liquid crystal cells 2.

[0062] In the case of frontal radiation incidence, however, both lateral radiation sensors 3, 5 would deliver signals V3, V5 of the same magnitude, so that the mean value VM of all partial signals corresponds at least to the partial signal V4 of the central radiation sensor 4. In this case, the protective screen 1 is darkened to its maximum extent via the control electronics 6.

[0063] Furthermore, the value of the signal variable could be taken into account differently when summing the signal for the strength of the dimming. This is particularly true in order to achieve a different darkening effect across the width B and / or height H of the protective screen 1. Especially with optical lenses or separate lenses for both eyes in one spectacle frame, the signals from the photodiodes of both lenses can be taken into account when summing or controlling the dimming of the respective lenses, so that when light enters from the side, the darkening in the area of ​​the less irradiated lens leads to a reduced overall darkening of both lenses. As can also be seen in Fig. 3, the radiation sensors 3, 4, 5 and preferably the control electronics 6 can be integrated into the protective screen 1 or attached to it.Preferably, these elements are positioned in the region of the upper edge of the protective screen 1 and preferably in or near its sagittal plane S in an area adjacent to the liquid crystal elements 2.

[0064] Fig. 4 also includes a schematic basic circuit diagram for the radiation protection device according to the invention. The signals from the radiation sensors 3, 4, 5 are optionally preprocessed by signal conditioning circuits 17 assigned to these sensors and then fed to the control electronics 6 connected to the sensors 3, 4, 5 or to these circuits 17. The output of the control electronics 6 is connected to the liquid crystal element 2 in order to control its transmittance according to the algorithm implemented in the control electronics 6. The algorithm can be implemented as a hard-wired circuit, as a software module, optionally using artificial intelligence, or as a combination thereof. The algorithm can implement a pure on-off function of the liquid crystal cell 2, switching only between two transmission levels, preferably maximum transparency and maximum darkening.However, the transmission can also be switched in several stages, or can also cause a continuously variable transmission in direct proportional dependence on the radiation incident on at least one radiation sensor 3, 4 or 5 or on an overall signal of several, preferably all, radiation sensors 3, 4, 5 or any function thereof.

[0065] Furthermore, Fig. 4 shows the optional possibilities for manually influencing the transmission control by an actuating element 18 connected to the control electronics 6, for example an on / off button, a setting wheel for the transmittance or the characteristics of the algorithm, etc. Another optional possibility for influencing the control electronics 6 is control via an external operating unit, for example a mobile phone 20, which communicates wirelessly with an external receiving module 19 connected to the control electronics 6. The receiving module 19 could also be directly integrated into the control electronics 6. Data can also be input via the mobile phone 20, which can then be displayed in the wearer's field of vision by controlling the liquid crystal cell 2.For example, it is also possible to assign a liquid crystal cell 2 or a group of adjacent cells to each radiation sensor 3, 4, 5, wherein the transmittance of the protective screen 1 in the area of ​​this liquid crystal cell 2 or group of cells is controlled individually depending on the radiation intensity, which is determined by the assigned radiation sensor 3, 4, 5. However, regardless of the control described above, it is also possible for the entire liquid crystal element or the liquid crystal cell or cells to be controlled with the same control signal from the control electronics, thus achieving uniform darkening over the entire surface of the protective screen 1.

[0066] A further embodiment provides that the protective screen 1 or the respective liquid crystal cell 2 or group of cells is brightened in the activated state and darkened in the deactivated state.

[0067] A further embodiment of the protective device according to the invention is shown in Fig. 5. In order to be able to optimally take into account incident radiation from directions oblique to the transverse plane T, at least one of the sensor surfaces 7, 8, 9 can be slightly inclined with respect to the vertical axis V. Preferably, at least the sensor surface 8 of the central radiation sensor 4 is slightly inclined with respect to the vertical axis V of the protective screen 1 and encloses an angle of less than 45° with it, the same also applying to the associated sensor plane SE4, which also encloses this angle with the vertical axis V, which angle is preferably between 1° and 33°, preferably between 3° and 25°.A larger angular range in the sagittal plane S can be covered by an embodiment in which, for example, the central sensor surface 8 and the sensor surfaces 7 and 9 of the adjacent radiation sensors are tilted in different directions around horizontal axes. This could, for example, result in less dimming when the sun is high in the sky due to the lower direct glare, whereas a stronger dimming occurs when the sun is low in the sky, especially when driving or walking.

[0068] As an alternative to the design of the control electronics 6 just described, it could also be designed to control the transmittance of the liquid crystal cell 2 depending on the respective highest control signal of all light sensors 3, 4, 5. According to a further embodiment of the invention, it is possible for at least one of the radiation sensors 3, 4, 5 to be arranged on the side of the protective pane 1 opposite the liquid crystal element 2, i.e., its outer side A.

[0069] An embodiment of a radiation protection device that is advantageous due to its comfortable portability is shown in Fig. 6 and, in section in the sagittal plane, also in Fig. 7. This embodiment comprises a support frame 12 and at least one protective screen 1 that is mounted on or in this support frame 12 or is replaceably connected to it. The protective screen 1 covers at least a large part of the field of vision of at least one eye. In the first embodiment with a support frame 12 shown in Fig. 6, at least one of the radiation sensors 3, 4, 5 is integrated into the protective screen 1 or arranged on it. Preferably, all of the radiation sensors 3, 4, 5 and, particularly preferably, the control electronics 6 are also integrated into the protective screen 1 or attached to it.In order to restrict the field of vision as little as possible, said elements are preferably positioned close to the upper edge of the protective screen 1 and as centrally as possible in the area of ​​the sagittal plane S.

[0070] The embodiment of Fig. 6 has a protective screen 1 that continuously covers the field of vision of both eyes and extends from the area of ​​one temple 13 to the opposite temple 13. The temples 13 are attached to the sides of a frame 14, preferably in a foldable manner, which encloses the edge area of ​​the protective screen 1, preferably along the entire circumference. The frame 14 and also the protective screen 1 have a nose recess 15 in the area of ​​the sagittal plane S, and the protective screen 1 has the smallest height. Any additional photodiode 10 and / or a photovoltaic element 11 as a power supply for the control electronics 6 and / or for the liquid crystal cell 2 are also preferably integrated into the support frame 12. The preferred position for this is the upper edge of the frame 14 in the central area around the sagittal plane S.

[0071] The protective screen 1 can be connected to the support frame 12 in a replaceable manner, which is particularly easy to do if the support frame 12 has a frame 14 that is open at the bottom and is connected or connectable to the protective screen 1 only in the area of ​​the upper edge of the protective screen 1, if necessary up to the lateral area of ​​the frame 12. In this case too, a nose recess 15 in the protective screen 1 is advantageous. Fig. 8 shows a further embodiment of a protective device with a support frame 12 according to the invention, in which two protective screens 1 are held on or in the frame 14 of the support frame 12, each of which covers at least a large part of the field of vision of one eye. These separate protective screens 1 can also be connected to the support frame 12 in a detachable or replaceable manner.

[0072] The frame 14 of the support frame 12 completely encloses both protective screens 1, preferably along their edges. For increased wearing comfort and secure positioning of the protective device in the region of the sagittal plane S or the vertical axis V forming an axis of symmetry, a nose recess 15 is provided, extending from the lower edge and over part of the height of the protective screens 1 toward the upper edge of the frame 13 of the support frame 12.

[0073] Here, an arrangement of at least two radiation sensors 4 and 16 or 4 and 5 is provided for each of the protective panes 1, wherein, for a particularly advantageous variant of this embodiment, the two middle radiation sensors 4 and 16 correspond in their alignment to the planes and axes of the protective device to the central radiation sensor 4 of the protective pane 1 of Figs. 1 to 5.

[0074] In any case, for one and the same protective pane 1, the sensor plane SE3 of an external radiation sensor 3 intersects the sensor plane SE16 of an internal sensor 16 at an acute angle a of less than 45°, as explained above for the other embodiments. The same applies to the opposite protective pane 1, in a mirrored arrangement.

[0075] In all embodiments described above, especially of course in those with radiation sensors 3, 4, 5 and / or control electronics 6 on or in a support frame 12 and liquid crystal cell(s) 2 on or in the protective screen 1, the contacting can be accomplished by printed conductor tracks and contact elements.

[0076] The control electronics 6 can, if necessary, be expanded with various modules and functionalities, particularly if the space available is relatively large due to positioning in the support frame 12, but also with the control electronics 6 in or on the protective screen 1. Modules for receiving and displaying various information could be integrated, for example, distances to objects in the field of view, the speed of the wearer of the protective device, but also general information from weather services, warning services, or the like. Such data can also come from a mobile phone transmitted via Bluetooth or a similar protocol if the electro-optical protective device is equipped with a corresponding data interface. A mobile radio module could also be integrated into the control electronics 6 or be present in the support frame 12 or in the protective screen 1.

[0077] The control of the liquid crystal cells 2 or the retrieval of certain functions of the control electronics 6 can also be carried out by actuating elements on the protective glass 1 or on the support frame 12, at least in a supplementary or bridging manner.

[0078] The radiation sensors 3, 4, 5 can be protected by a common or separate sensor covers, wherein protective covers can be provided in the area of ​​the respective actual sensor surfaces 7, 8, 9 in order to protect the sensors mechanically and / or against moisture, contamination, etc. The sensor cover consists of a partially translucent and / or transparent material which absorbs, reflects, or transmits the radiation depending on the wavelength of the radiation. Preferably, the sensor cover is at least partially at least substantially translucent to radiation from an infrared light spectrum, in particular the range in which the radiation sensors 3, 4, 5 have their highest sensitivity. The transparency of the sensor cover in this wavelength range is more than 30%, preferably more than 80%, optimally approximately 90%.

[0079] The sensor cover can be partially formed integrally with the material of the protective screen 1 or the frame 14 and made of the same material as these components, but preferably have a thinner material thickness. In principle, it would also be conceivable for the sensor cover and the protective screen 1 and / or the support frame 12 or the frame 14 to be made of different materials and / or manufactured separately and joined in one piece in any manner deemed appropriate by a person skilled in the art, such as by means of an adhesive process.

[0080] The embodiments described above show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action by means of the objective invention.

[0081] Reference symbol list

[0082] 1 protective screen B width

[0083] 2 Liquid crystal element H height

[0084] 2a Liquid crystal cell I inside

[0085] 2b Liquid crystal cell A outside

[0086] 3 Radiation sensor V3 Signal Sensor 3

[0087] 4 Radiation sensor V4 Signal Sensor 4

[0088] 5 Radiation sensor V5 Signal Sensor 5

[0089] 6 Control electronics VS sum signal

[0090] 7 Sensor level VM mean signal

[0091] 8 Sensor level

[0092] 9 Sensor level

[0093] 10 photodiodes

[0094] 11 Photovoltaic element

[0095] 12 Support frame

[0096] 13 brackets

[0097] 14 frames

[0098] 15 Nose recess

[0099] 16 radiation sensor

[0100] 17 Sensor electronics

[0101] 18 Control element

[0102] 19 Radio module

[0103] 20 mobile devices

[0104] F Frontal plane

[0105] Q transverse axis

[0106] S Sagittal plane

[0107] SE3 Sensor level Sensor 3

[0108] SE4 Sensor level Sensor 4

[0109] SE5 Sensor level Sensor 5

[0110] V Vertical axis a Angle between sensor planes

Claims

P a t e n t a n s p r ü c h e 1. An electro-optical radiation protection device, in particular a light protection device, comprising at least one electro-optical protective screen (1) which covers at least the field of vision of one eye and comprises at least one liquid crystal element (2) which covers substantially the entire field of vision of said protective screen (1), at least two radiation sensors (3, 4, 5), each of which generates a control signal depending on the intensity of the incident radiation, and control electronics (6) which is designed to receive the control signals and to control the or each liquid crystal cell (2) and which controls the transmittance (T) of the protective screen (1), characterized in that the radiation sensors (3, 4, 5) are designed as photodiodes with a sensitivity range between 400 and 1100 nm and preferably the highest sensitivity in the near infrared, in particular between 800 nm and 900 nm, wherein the sensor surfaces (7, 8, 9) form sensor planes (SE3, SE4,SE5), wherein at least two of the sensor planes (SE3, SE4 or SE4, SE5 or SE3 SE5) intersect each other at an angle of less than 45°, and wherein the intersection line of these sensor planes (SE3, SE4 or SE4, SE5 or SE3, SE5) preferably lies in or parallel to the sagittal plane (S) of the protective screen (1).

2. Radiation protection device according to claim 1, characterized in that at least three radiation sensors (3, 4, 5) are provided per protective pane (1), wherein the sensor surface (8) of at least one central radiation sensor (4) is oriented parallel to the transverse axis of the protective pane (1), and wherein the sensor planes (SE3, SE5) of at least one radiation sensor (3, 5) arranged laterally on both sides of the or each central radiation sensor (4) or the central radiation sensors, preferably of the respectively immediately adjacent radiation sensor, intersect the sensor plane (SE4) of each central radiation sensor (4) at an angle of less than 45°.

3. Radiation protection device according to claim 1 or 2, characterized in that the sensor planes (SE3, SE4 or SE4, SE5 or SE3, SE5) enclose an angle between 1° and 33°, preferably between 3° and 25°.

4. Radiation protection device according to one of claims 1 to 3, characterized in that at least one of the sensor planes (SE3, SE4, SE5) forms an angle of less than 45° with the vertical axis (V) of the protective screen (1).

5. Radiation protection device according to one of claims 1 to 4, characterized in that the photodiodes provided as radiation sensors (3, 4, 5) are operated in photovoltaic mode and preferably in series connection, wherein the output voltage is fed into the control electronics (6) as a control signal and is preferably also used for the energy supply of the control electronics (6) and / or the liquid crystal cell (2), wherein preferably a signal conditioning circuit (17) is interposed between each radiation sensor (3, 4, 5) and the control electronics (6). A photodiode (10) and / or a photovoltaic element (11) is connected to the control electronics (6) and / or the liquid crystal cell (2) as an energy supply for the latter.

6. Radiation protection device according to one of claims 1 to 5, characterized in that the control electronics (6) are designed to determine an average value from the signals of all light sensors (3, 4, 5) and to control the transmittance of the liquid crystal cell (2) depending on this average value, wherein preferably four radiation sensors are provided.

7. Radiation protection device according to one of claims 1 to 5, characterized in that the control electronics (6) are designed to control the transmittance of the liquid crystal cell (2) depending on the respective highest control signal of all light sensors (3, 4, 5).

8. Radiation protection device according to one of claims 1 to 7, characterized in that at least one of the radiation sensors (3, 4, 5) is arranged on the side of the protective screen (1) opposite the liquid crystal element (2).

9. Radiation protection device according to one of claims 1 to 8, characterized in that the radiation sensors (3, 4, 5) and preferably the control electronics (6) in the protective disc (1) are integrated or attached thereto, preferably in the region of the upper edge and preferably in or near the sagittal plane.

10. Radiation protection device according to one of claims 1 to 9, characterized in that each radiation sensor (3, 4, 5) is assigned a liquid crystal cell (2), wherein the transmittance of the protective screen (1) in the region of each liquid crystal cell (2) is controlled individually depending on the incidence of light which is determined by the assigned radiation sensor (3, 4, 5).

11. Radiation protection device according to one of claims 1 to 10, characterized in that the protective screen (1) is brightened in the activated state and darkened in the deactivated state.

12. Radiation protection device according to one of claims 1 to 11, comprising a support frame (12) and at least one protective screen (1) which is mounted on or in a support frame (12) or is replaceably connected thereto and covers at least a large part of the field of view of at least one eye, characterized in that at least one of the radiation sensors (3, 4, 5), preferably all of the radiation sensors, and preferably also the control electronics (6) is / are integrated into the protective screen (1) or fastened thereto, preferably near the upper edge of the protective screen (1).

13. Radiation protection device according to one of claims 1 to 8, 10 or 11, comprising a support frame (12) and at least one protective screen (1) which is mounted on or in a support frame (12) or is replaceably connected thereto and covers at least a large part of the field of view of at least one eye, characterized in that at least some of the radiation sensors (3, 4, 5), preferably all of the radiation sensors (3, 4, 5), and the control electronics (6) are integrated into the support frame (12) or are mounted thereon, preferably near the upper edge of the protective screen (1) and in or near the sagittal plane of the support frame.

14. Radiation protection device according to claim 12 or 13, characterized in that a photodiode and / or a photovoltaic element is used as energy supply for the Control electronics and / or for the liquid crystal cell (2) are connected thereto and are preferably integrated in the support frame (12) or attached to the support frame (12).

15. Radiation protection device according to claim 13 or 14, characterized in that two protective screens (1) are mounted on or in a support frame (12) or are interchangeably connected thereto, wherein the protective screens (1) are arranged in such a way as to each cover at least a large part of the field of vision of one eye.

16. Radiation protection device according to claim 15, characterized in that the support frame (12) completely encloses both protective panes (1) along their edge and has, in the region of the sagittal plane or the central axis (23) forming an axis of symmetry, a nose recess (15) starting from the lower edge and extending over part of the height of the protective panes (1) in the direction of the upper edge of the support frame (12).

17. Radiation protection device according to one of claims 12 to 14, characterized in that a protective screen (1) is mounted on or in a support frame (12) or is replaceably connected to the latter and covers at least a large part of the field of view of both eyes, wherein preferably the protective screen (1) and / or an edge of the support frame (12) enclosing the protective screen (1) in the region of the sagittal plane or the central axis (23) forming an axis of symmetry has / have a nose recess (15) starting from the lower edge and extending over part of the width of the protective screen (1) in the direction of the upper edge of the protective screen (1).

Images