Liquid storage system

Abstract

The invention relates to a system for storing liquids, in particular for a household appliance, comprising at least one container for storing a liquid and at least one level measuring device, wherein the level measuring device comprises at least one radiation source device which emits electromagnetic radiation and at least one detection device for electromagnetic radiation, wherein the at least one container has a reflection element which has only one interface with a fluid located in the container.

Description

[0001] The invention relates to a system for storing liquids, in particular for a household appliance, comprising at least one container for storing a liquid and at least one level measuring device.

[0002] Many devices and appliances, particularly household appliances, include containers for storing various liquids. A suitable household appliance could be a water-using household appliance, such as a dishwasher or washing machine. Detergent, rinse aid, or other treatment agents could be stored in at least one container. However, it would also be conceivable for the container to be a storage medium for condensate in a household appliance, such as a refrigerator or dryer. It is often desirable to obtain information about the fill level of such containers. Such information could be used to indicate the need for filling or emptying.

[0003] The object of the present invention is to provide a system for storing liquids which enables particularly simple level determination.

[0004] The object is achieved by the subject matter of claim 1. The subclaims comprise preferred embodiments.

[0005] According to the present invention, a system for storing liquids, in particular for a household appliance, is provided, comprising at least one container for storing a liquid and at least one fill level measuring device, wherein the fill level measuring device comprises at least one radiation source device which emits electromagnetic radiation and at least one detection device for electromagnetic radiation, wherein the at least one container has a reflection element which has only one interface with a fluid located in the container.

[0006] When electromagnetic radiation strikes an interface between materials with different refractive indices, part of the radiation is reflected and part of the radiation enters the adjacent material. This behavior depends on the so-called angle of incidence α of the electromagnetic radiation. In ray optics, the angle of incidence α is the addition of the angle between the ray and the horizon to 90°. When a ray passes through an optical interface, its angle of incidence is the angle to the normal to this surface. At an angle of incidence α greater than the so-called critical angle α T total internal reflection of the radiation occurs. The radiation is thus completely reflected. The critical angle α T is defined as follows: sin αT=n1n2 where n1 and n2 are the refractive indices of the adjacent materials. Preferably, n1 is the refractive index for air or fluid. Advantageously, the refractive index of air is n Luft smaller than the refractive index of the fluid n Fluid (n Luft < n Fluid ). In this case, n2 is preferably the refractive index for the material of the reflection element. The critical angle α is preferably determined T the electromagnetic radiation from the at least one radiation source device from the refractive index n of the reflection element.

[0007] Preferably, the electromagnetic radiation from the at least one radiation source device strikes the interface at a predetermined angle of incidence α or a predetermined angle of incidence range. In an advantageous first state of the system, the container is not filled with the liquid. Accordingly, the fluid in the container is preferably air. In the first state of the system, the reflection element thus preferably has an interface with air. In an advantageous second state of the system, the container is filled with the liquid. Accordingly, the fluid in the container is preferably the corresponding liquid. In the second state of the system, the reflection element thus preferably has an interface with the corresponding liquid. Preferably, in the first state of the system, at least a portion of the electromagnetic radiation is totally reflected at the only one interface.Preferably, the reflected portion is detected by the at least one detection device. Advantageously, in the second state, there is no total reflection of the electromagnetic radiation emitted by the at least one radiation source device from the only one interface at the predetermined angle of incidence α.

[0008] In the system according to the invention, only one interface with a fluid located in the container is provided, at which total internal reflection occurs. In contrast to other conceivable embodiments with two adjacent interfaces enclosing a predetermined angle, the system according to the invention requires significantly less design effort for the at least one container.

[0009] According to a preferred embodiment, the reflection element is arranged in or on an outer wall of the at least one container. The interface of the reflection element is preferably planar. A planar interface extends flatly or evenly without curvatures or the like. According to a further possible embodiment, the interface is curved, parabolic, or formed as a spherical segment. According to a further aspect, an optical element can be integrated into the interface. Such an optical element can be a lens, for example. Advantageously, the reflection element consists of a material that is transparent to the electromagnetic radiation emitted by the at least one radiation source device. The reflection element is preferably made of glass or a polymer, for example polymethyl methacrylate (PMMA, also acrylic glass).The reflection element can preferably also have several sections made of different materials.

[0010] According to a further preferred embodiment, the at least one container is a hollow body which is essentially rectangular or square. However, other shapes would also be conceivable, for example bodies with a polygonal or rounded base. The container extends along a height axis Z, a longitudinal axis X and a width axis Y. If there is liquid in the container, the liquid has a level or an upper surface. This level extends essentially within a plane spanned by the longitudinal axis X and the width axis Y. The orientation of the level, however, depends on the installation of the at least one container in, for example, a household appliance or on the orientation of the container to the acting gravitational force.

[0011] According to a further preferred embodiment, the reflection element comprises an optical prism. Advantageously, a first side surface of the optical prism forms only one interface with a fluid located in the container. The prism can be of any desired design. Preferably, the first side surface forming the interface is planar. The prism can preferably have discontinuities along its length. The prism can preferably contain optically active structures, for example, lens elements and / or a surface roughness to assist scattering.

[0012] According to a preferred embodiment, the optical prism has a right prism with a triangle as its base. Such a prism preferably comprises a first, a second, and a third side surface. Electromagnetic radiation emitted by the at least one radiation source device preferably enters the optical prism through a second side surface of the latter and reaches the first side surface of the optical prism or the interface. In a first state, at least a portion of this electromagnetic radiation is totally reflected at the interface and then exits the optical prism again through the third side surface. From there, the reflected radiation advantageously reaches the at least one detection device.

[0013] According to a further advantageous embodiment, the reflection element is arranged on or in the outer wall of the at least one container such that the interface is inclined or oblique to a fictitious plane that is parallel to the liquid level. Preferably, the reflection element is arranged on or in the outer wall of the at least one container such that the interface forms an angle θ with a fictitious plane that is parallel to the liquid level. Preferably, the angle θ is less than 180°.

[0014] According to a further advantageous embodiment, the reflection element is arranged on or in the outer wall of the at least one container such that the interface is substantially parallel to a liquid level in the container. Advantageously, the angle θ is substantially equal to 180°. Preferably, the first side surface of the optical prism is arranged substantially parallel to the liquid level.

[0015] According to a preferred embodiment, the reflection element comprises a window element, which in turn encompasses the boundary surface. The window element is preferably integrated into an outer wall of the at least one container. The window element can be planar, curved, parabolic, or formed as a spherical segment.

[0016] According to a further advantageous embodiment, the radiation source device comprises at least one radiation source. Preferably, the at least one radiation source is an LED, a laser, or a laser LED. Other suitable radiation sources would of course also be conceivable. Preferably, the electromagnetic radiation emitted by the radiation source device has a wavelength λ in a range between approximately 300 nm and approximately 1400 nm. Preferably, the electromagnetic radiation emitted by the at least one radiation source device is polarized. Preferably, the electromagnetic radiation is linearly, circularly, or elliptically polarized. Preferably, the at least one radiation source already emits the polarized electromagnetic radiation. Alternatively, the radiation source device can comprise at least one polarizer.According to a further preferred embodiment, the electromagnetic radiation emitted by the at least one radiation source device is unpolarized. Although the reflectivity below the critical angle would depend on the polarization directions, the critical angle is the same for the different polarization angles.

[0017] Preferably, the at least one detection element comprises at least one sensor element. Such a sensor element is preferably suitable and intended for detecting electromagnetic radiation. Such a sensor element can be, for example, a phototransistor.

[0018] According to a further advantageous embodiment, the at least one radiation source device and the at least one detection device are arranged on a common carrier device. The carrier device preferably comprises at least one plate-like element. The plate-like element is preferably a circuit board or printed circuit board (PCB). It would be conceivable for the carrier device to comprise a housing in which the at least one plate-like element is arranged.

[0019] According to a further advantageous embodiment, a central beam direction is assigned to the at least one radiation source device and the at least one detection direction. The at least one radiation source device has an emission angle β E The emission angle β Edescribes the area in which the electromagnetic radiation propagates from the at least one radiation source device. Preferably, the emission of the at least one radiation source device is not distributed isotropically within the emission angle. In the case of a radiation source device in the form of an LED, a variety of radiation behaviors are possible. Such radiation behaviors can be club-like, have a so-called batwing characteristic, or have a side-emitter characteristic. Of course, other characteristics are also conceivable. Preferably, the at least one detection device has an acceptance angle β A The acceptance angle β Adescribes the area in which the electromagnetic radiation propagates toward the at least one detection device. Preferably, the detection efficiency of the at least one detection device is not isotropic within the acceptance angle. The central beam direction of the at least one detection device would therefore extend along the central height axis of said cone.

[0020] Preferably, the central beam direction of the at least one radiation source device and / or the central beam direction of the at least one detection device does not extend perpendicular to the plate-like element of the carrier device. A central beam direction of the at least one radiation source device that is not perpendicular to the plate-like element of the carrier device can preferably be enabled by at least one radiation source device that has at least one radiation source configured as a component with bent wire connections. Alternatively or cumulatively, the at least one radiation source can be an SMD LED (surface-mounted LED) with a tilted optical axis or a SideLooker LED.

[0021] A central beam direction of the at least one detection device that is not perpendicular to the plate-like element of the carrier device can preferably be enabled by at least one detection device that has a sensor element designed as a component with bent wire connections. Preferably, the aforementioned wire connections of the radiation source and / or the sensor element are arranged on the circuit board using a through-hole mounting (also called through-hole technology THT).

[0022] According to a further preferred embodiment, the carrier device comprises a curved circuit board. Such a curved circuit board is preferably mechanically stable. According to a further aspect, the carrier device could comprise a flexible circuit board. The circuit board preferably has a first section on or at which the at least one radiation source device is arranged. Furthermore, it is advantageous for the circuit board to have a second section on or at which the at least one detection device is arranged. The first section and the second section preferably enclose an angle γ. The angle γ is preferably less than 180°. Such an advantageous embodiment with the two sections enclosing the angle γ can be made possible by a curved circuit board or a flexible circuit board.

[0023] According to a further preferred embodiment, the at least one radiation source device has an emission angle β E and the at least one detection device has an acceptance angle β A Preferably, the at least one radiation source device is arranged relative to the interface such that at least a part of the electromagnetic radiation is within the emission angle β E hits the interface. Preferably, the at least one detection device is arranged relative to the interface such that at least a part of the reflected electromagnetic radiation is within the acceptance angle β A lies.

[0024] According to a further preferred embodiment, the at least one radiation source device is arranged relative to the interface in such a way that only a part of the electromagnetic radiation is within the emission angle β Ehits the interface. Preferably, the at least one radiation source device has a large emission angle β E Preferably, the at least one radiation source device is approximately a Lambert radiator. Preferably, the at least one radiation source device has at least one radiation source which is approximately a Lambert radiator. A Lambert radiator follows Lambert's cosine law, which states that a radiant intensity which is incident from an angle θ L (relative to the surface normal) is observed, proportional to cos (θ L). Preferably, the emission of the at least one radiation source device is not distributed isotropically within the emission angle. Such a configuration allows the at least one radiation source device to be attached to the circuit board in such a way that it is substantially parallel to the circuit board. Preferably, the portion of the electromagnetic radiation that impinges on the interface is sufficient to enable adequate detection.

[0025] Preferably, the at least one detection device is arranged relative to the interface such that only a part of the reflected electromagnetic radiation is within the acceptance angle β A Preferably, at least one detection device has a large acceptance angle β APreferably, at least one detection device is approximately a Lambert detector. Such a Lambert detector is to be defined analogously to the Lambert radiator described above. Preferably, the at least one has at least one sensor element which is approximately a Lambert detector. With such a configuration, the at least one detection device can be attached to the circuit board in such a way that it is essentially parallel to the circuit board. Preferably, the proportion of electromagnetic radiation that impinges on the at least one detection device is sufficient to enable adequate detection.

[0026] Preferably, both the at least one radiation source device is approximately a Lambert radiator and the at least one detection device is approximately a Lambert detector.

[0027] Preferably, half the emission angle (β E) greater than or equal to 45°. Half the acceptance angle (β A ) greater than or equal to 45°. Emission angles (β E ) and the acceptance angle (β A ) is to be understood analogously to the definition of the aperture angle in the definition of the numerical aperture. Such an aperture angle of an optical system preferably corresponds to the maximum possible angle of a light beam emanating from the focused object and just captured by the lens. The aperture angle indicates the size of the maximum cone of light emanating from the object and captured by the lens.

[0028] According to a further preferred embodiment, at least one first diaphragm device is provided, which spatially limits the electromagnetic radiation directed onto the interface. Preferably, at least one second diaphragm device is provided, which spatially limits the reflected electromagnetic radiation. It would also be conceivable for at least one third diaphragm device to be provided, which spatially limits both the electromagnetic radiation directed onto the interface and the reflected electromagnetic radiation. Preferably, the at least one first diaphragm device and / or the at least one second diaphragm device and / or the at least one third diaphragm device is designed as a pinhole diaphragm or a slit diaphragm. When using a radiation source device with a large emission angle β EThis prevents irradiation in unwanted areas. Likewise, unwanted irradiation from reflected radiation can be avoided.

[0029] According to a further preferred embodiment, a first window element is arranged between the at least one radiation source device and the interface. Preferably, a second window element is arranged between the interface and the at least one detection device.

[0030] According to a further preferred embodiment, a first optical element is arranged on or near the at least one radiation source device. Preferably, a second optical element is arranged on or near the at least one detection device. Advantageously, the first optical element and / or the second optical element is a prism or a lens.

[0031] According to a further advantageous embodiment, at least one radiation guidance device is provided. Preferably, the electromagnetic radiation from the at least one radiation source device is guided sectionally in the radiation guidance device. Preferably, the electromagnetic radiation reflected at the interface is guided sectionally in the radiation guidance device. Preferably, the radiation source device is rod-shaped and comprises a beveled distal end. Preferably, at the beveled distal end, the electromagnetic radiation that has passed through the radiation source device is totally reflected and redirected to the interface. Preferably, at the beveled distal end, the electromagnetic radiation reflected at the interface is totally reflected and guided into the radiation source device.

[0032] According to a further advantageous embodiment, a plurality of containers are provided for storing a liquid. Advantageously, only one radiation source device is provided. Preferably, a plurality of radiation conduction devices are provided, which guide electromagnetic radiation from the radiation source device to the respective boundary surfaces of the containers. Advantageously, a plurality of detection devices are provided. Preferably, each container is assigned a detection device.

[0033] It is understood that the above-mentioned embodiments can be combined in any desired manner. Thus, the at least one radiation source device of one embodiment can be combined with the at least one detection device of another embodiment.

[0034] This task is also solved by a household appliance with a liquid storage system. The household appliance can be equipped with all the features described above in the context of the system, individually or in combination, and vice versa.

[0035] According to a particularly preferred embodiment, the system for storing liquids is part of a dosing device. The household appliance is preferably a water-conducting household appliance, for example, a dishwasher or a washing machine. The liquid stored in the at least one container is preferably a treatment agent, for example, a detergent, a dishwashing liquid, a rinse aid, a fabric softener, or the like. The at least one container is preferably removable from the dosing device.

[0036] Preferably, the household appliance is a dryer, with the dryer's condensate being stored in the container. A liquid storage system can, for example, detect when a container needs to be emptied.

[0037] Further advantages, objects, and features of the present invention will be explained in the following description of the accompanying figures. Similar components may have the same reference numerals in the various embodiments.

[0038] The figures show: Fig. 1 a side view of the system according to one embodiment; Fig. 2 is a perspective view of the system according to one embodiment; Fig. 3 a side view of the system according to one embodiment; Fig. 4 is a perspective view of the system according to one embodiment; Fig. 5 a section of an arrangement of the system according to one embodiment; Fig. 5 a section of an arrangement of the system according to one embodiment; Fig. 6 a system with an unfavourable design; Fig. 7 a schematic comparison of an unfavorable and an advantageous embodiment; Fig. 8 measurement curves of reflectivity as a function of the angle of incidence; Fig. 9 a section of an arrangement of the system according to a further embodiment; Fig. 10 a section of an arrangement of the system according to a further embodiment; Fig. 11 a section of an arrangement of the system according to a further embodiment; Fig. 12 a section of an arrangement of the system according to a further embodiment; Fig. 13 a section of an arrangement of the system according to a further embodiment; Fig. 14 a section of an arrangement of the system according to a further embodiment; Fig. 15 a section of an arrangement of the system according to a further embodiment; Fig. 16 a section of an arrangement of the system according to a further embodiment; Fig. 17 a section of an arrangement of the system according to a further embodiment; Fig. 18 a section of an arrangement of the system according to a further embodiment; Fig. 19 a section of an arrangement of the system according to a further embodiment; Fig. 20 a section of an arrangement of the system according to a further embodiment; Fig. 21 a section of an arrangement of the system according to a further embodiment; Fig. 22 a section of an arrangement of the system according to a further embodiment; Fig. 23 a schematic diagram of a household appliance according to one embodiment;

[0039] In the Fig. 1-5 and 9-22, a system 1 for storing liquids, in particular for a household appliance 2, is shown. The system 1 comprises at least one container 3 for storing a liquid and at least one fill level measuring device 4, wherein the fill level measuring device 4 comprises at least one radiation source device 5 which emits electromagnetic radiation 6 and at least one detection device 7 for electromagnetic radiation 8, wherein the at least one container 3 has a reflection element 9 which has only one interface 10 with a fluid located in the container 3.

[0040] The at least one container 3 extends along a height axis Z, a longitudinal axis X, and a width axis Y. The container 3 is a hollow body that is essentially rectangular or square in shape. However, other shapes are also conceivable, for example bodies with a polygonal or rounded base. The container 3 further comprises an outer wall 11. If there is liquid in the container 3, the liquid has a level, or an upper surface. This level extends essentially within a plane spanned by the longitudinal axis X and the width axis Y.

[0041] The reflection element 9 is arranged in or on an outer wall 11 of the at least one container 3. The interface 10 can be planar, curved, parabolic, or formed as a spherical segment. According to an advantageous embodiment, an optical element can also be integrated into the interface 10. The reflection element 6 can also be made of glass or a polymer.

[0042] The electromagnetic radiation 6 from the at least one radiation source device 5 strikes the interface 10 at a predetermined angle of incidence α or a predetermined angle of incidence range. In a first state of the system, the container 3 is not filled with the liquid. The interface thus lies on the fluid air. There is therefore a transition from the material of the reflection element 9, for example glass or Plexiglas, to air. As a result of such a transition, in the first state of the system, at least a portion of the electromagnetic radiation 6 that strikes the interface at a predetermined angle of incidence α is totally reflected at the interface 10. The reflected electromagnetic radiation 8 is then detected by the at least one detection device 7. In a second state of the system, the container 3 is filled with the liquid.In the second state of the system, there is therefore a transition from the material of the reflection element 9, for example, glass or Plexiglas, to the liquid. Such a transition prevents total reflection of the electromagnetic radiation 6 at the only interface 10 at the specified angle of incidence α. Such a lack of total reflection at the specified angle of incidence α can also be detected by the at least one detection device 7. The interface 10 can also be referred to as an optically active surface.

[0043] The reflection element 9 comprises an optical prism 12. A first side surface 12a of the optical prism 12 forms only one interface 10 with a fluid located in the container 3. The prism can have fundamentally different shapes; in the following, without loss of generality, reference is made to a right prism with a triangle as its base. The emitted electromagnetic radiation 6 enters the prism 12 through a second side surface 12b and reaches the interface 10 or the first side surface 12a. If the system is in the first state, the electromagnetic radiation 6 is totally reflected at the interface 10 and then exits the prism 12 through the third side surface 12c as reflected electromagnetic radiation 8.

[0044] The radiation source device 5 comprises at least one radiation source 5a. The at least one radiation source 5a can be an LED, a laser, or a superluminescent diode (SLED).

[0045] The at least one radiation source device 5 and the at least one detection device 7 are arranged on a common carrier device 13. The carrier device 13 comprises a plate-like element 13a or a printed circuit board (PCB) on which the at least one radiation source device 5 and the at least one detection device 7 are mounted. It would be conceivable for the carrier device 13 to comprise a housing (not shown in the figures) in which the at least one plate-like element 13a is arranged.

[0046] In Fig. Figure 6 shows an embodiment that is considered disadvantageous. According to this embodiment, two interfaces exist with the fluid, which can be air or liquid, in the container 3. The incident electromagnetic radiation 6 is reflected at the first interface to the second interface. From the second interface, the electromagnetic radiation is then reflected to the detection device. However, the presently claimed invention has only one interface with the fluid located in the container. The embodiment according to the invention has the advantage of enabling a structurally simpler construction of the container. The geometry of the container can be simplified. With disadvantageous, more complicated internal structures of the containers, the stored liquid can more easily remain on the surfaces after emptying. The reason for this is the surface tension at edges with an angle of <180°. Fig. 7, the unfavorable embodiment under a) is compared with the inventive embodiment b). In contrast to the unfavorable embodiment, the inventive embodiment has further advantages with regard to tolerances. The unfavorable embodiment a) has translational tolerances X'=0, Y'=2X and Z=0. In contrast, the inventive embodiment b) has translational tolerances X'=1.41 (sqrt2), Y'=2X and Z=0. The unfavorable embodiment a) has angular tolerances X'=4X', Y'=4X' and Z=4X'. In contrast, the inventive embodiment b) has angular tolerances X'=2X', Y'=2X' and Z=2X'. The inventive embodiment thus has better translational tolerances and better angular tolerances since total internal reflection only occurs at one interface.

[0047] In the Fig. 1 and Fig. 2 shows an embodiment of the system, wherein Fig. 1 is a side view and Fig. 2 is a perspective view. From these figures, it can be seen that the reflection element 9, for example a prism 12, is arranged in or on the outer wall 11 of the at least one container 3 in such a way that the interface 10 runs at an angle or obliquely to a fictitious plane 22 which is parallel to the level of the liquid. The interface 10 and the fictitious plane 22 thus enclose an angle θ which is less than 180°. The interface 10 extends obliquely between a lower outer wall 11a and a lateral outer wall 11b. The interface 10 is thus arranged essentially laterally at the lower region of the container. It is clearly evident from the figure that, due to the course of the interface 10, a corner section of the container has been replaced by the reflection element 9.The circuit board 13a, on which the at least one radiation source device 5 and the at least one detection device 7 are arranged, is arranged substantially parallel to the interface 10.

[0048] In the Fig. 3 and Fig. 4 shows another embodiment of the system, wherein Fig. 3 is a side view and Fig. 4 is a perspective view. From these figures, it can be seen that the reflection element 9, for example a prism 12, is arranged on or in the container 2 such that the interface 10 runs substantially parallel to a fictitious plane 22, which is parallel to the level of the liquid. The interface 10 and the fictitious plane 22 thus enclose an angle θ that is substantially 180°. The interface 10 is arranged in or on the lower outer wall 11a. The circuit board 13a, on which the at least one radiation source device 5 and the at least one detection device 7 are arranged, is arranged substantially parallel to the interface 10.

[0049] In Fig. Figure 5 shows a section showing the prism 12, the support device 13 with the at least one radiation source device 5 and the at least one detection device 7, as well as the beam paths of the emitted electromagnetic radiation 6 and the reflected electromagnetic radiation 8. The angle ξ between the emitted electromagnetic radiation 6 and the second side surface 12b of the prism 12 can be 90°. However, other angle values ​​are also conceivable. The angle of incidence α depends on the respective material of the prism or the refractive index n of this material.

[0050] In Fig. Figure 8 shows the reflectivity as a function of the angle of incidence α (unpolarized radiation) for various materials of the reflection element 9. In Figure a), the refractive index of the material is n1 = 1.45. In Figure b), the refractive index of the material is n1 = 1.65. In Fig. c) the refractive index of the material is n1 = 1.55. The graphs also show the angle dependence of the total internal reflection in an unfilled state, where the fluid at the interface 10 is air, and a filled state, where the fluid at the interface 10 is the liquid. In the unfilled state, the critical angle α is n1 = 1.45. T approx. 43° at n1= 1.65 the critical angle α T approx. 37° and at n1= 1.5 the critical angle α T approx. 41°.

[0051] The at least one radiation source device 5 has an emission angle β E The emission angle β E describes the area in which the electromagnetic radiation 6 propagates from the at least one radiation source device 5. The at least one detection device has an acceptance angle β A The acceptance angle β Adescribes the area in which the electromagnetic radiation propagates toward the at least one detection device. Furthermore, a central beam direction 6a, 8a is assigned to the at least one radiation source device 5 and the at least one detection device 7.

[0052] The central beam direction 6a of the at least one radiation source device 5 and / or the central beam direction 8a of the at least one detection device 7 preferably do not extend perpendicular to the plate-like element 13a. This allows the electromagnetic radiation 6 to be incident at the predetermined angle of incidence α and the reflected electromagnetic radiation 8 to be detected at only one interface 10.

[0053] In Fig. Figure 9 illustrates an embodiment in which both the central beam direction 6a of the at least one radiation source device 5 and the central beam direction 8a of the at least one detection device 7 do not extend perpendicular to the plate-like element 13a. Of course, embodiments are conceivable in which only the at least one radiation source device 5 or the at least one detection device 7 have a central beam direction 6a, 8a that does not extend perpendicular to the plate-like element 13a.To enable such a central beam direction 6a, which does not extend perpendicular to the plate-like element 13a, the at least one radiation source device 5 can, for example, comprise at least one radiation source 5a, which is designed as a component with bent wire connections 5b. Alternatively or cumulatively, the at least one detection device 7 can comprise a sensor element 7a, which is designed as a component with bent wire connections 7b. The central beam direction 6a of the at least one radiation source device 5 and the circuit board 13a thus form an angle ϕ. S which is less than 90°. The central beam direction 8a of the at least one detection device 7 and the circuit board 13a thus form an angle φ Dwhich is less than 90°. The figure also clearly shows that the respective component is not mounted parallel to the circuit board 13a and thus at a certain distance from the surface of the circuit board. The respective wire connections 5b, 7b are attached to the circuit board using through-hole technology. Another possibility for enabling at least one radiation source device 5 with a central beam direction 6a that does not extend perpendicular to the plate-like element 13a is the use of side-looker LEDs.

[0054] In Fig. 10 shows an embodiment in which only the central beam direction 6a of the at least one radiation source device 5 does not extend perpendicular to the plate-like element 13a. The central beam direction 8a of the at least one detection device 7 extends substantially perpendicular to the plate-like element 13a. The central beam direction 6a of the at least one radiation source device 5 is, according to this embodiment, substantially parallel to the plate-like element 13a. The angle φ Sis thus essentially 0°. However, the plate-like element 13a is arranged relative to the container in such a way that the interface 10 runs obliquely thereto. An angle between a plane in which the interface 10 is located and between a plane in which the plate-like element 13a is located is thus less than 90° and greater than 0°; preferably, this angle lies in a range between 20° and 70°. According to this embodiment, at least one radiation source 5a of the radiation source device 5 is designed as a component with bent wire connections 5b. The radiation source 5a is not parallel to the circuit board 13a and is therefore attached to the circuit board at a certain distance from the surface of the circuit board. The respective wire connections 5b are attached to the circuit board using through-hole technology.

[0055] In Fig. 15 shows an alternative embodiment. Here, the circuit board 13, 13b, 13c has a first section 14, on or at which the at least one radiation source device 5 is arranged. Furthermore, the circuit board 13, 13b, 13c has a second section 15, on or at which the at least one detection device 7 is arranged. The first section 14 and the second section 15 form an angle γ which is less than 180°. Such a configuration can be achieved by a curved circuit board 13b or a flexible circuit board 13c. The circuit board 13b, 13c is arranged relative to the container 3 such that the interface 10 runs obliquely to both the first section 14 and the second section 15.An angle between a plane in which the interface 10 is located and a plane in which a section 15 is located is thus less than 90° and greater than 0°. This angle preferably lies in a range between 20° and 70°. The at least one radiation source device 5 and the at least one detection device 7 can thus be arranged substantially parallel to a surface of the respective section.

[0056] According to a further embodiment, the at least one radiation source device 5 is selected such that it has a large emission angle β E Preferably, the at least one radiation source device 5 is approximately a Lambert radiator. Alternatively or cumulatively, the at least one detection device 7 is selected such that it has a large acceptance angle β APreferably, at least one detection device 7 is approximately a Lambert detector. Such a radiation source device 5 and such a detection device 7 are in the embodiment according to Fig. 11. The at least one radiation source device 5 is arranged relative to the interface 10 such that only a part of the electromagnetic radiation 6 is within the emission angle β E strikes the interface 10. Furthermore, the at least one detection device 7 is arranged relative to the interface 10 such that only a part of the reflected electromagnetic radiation 8 is within the acceptance angle (β A ). Due to the large emission angle β E sufficient electromagnetic radiation 6 hits the interface 10. Due to the large acceptance angle β ASufficiently reflected electromagnetic radiation 8 strikes the at least one detection device 7, enabling effective detection. According to this embodiment, the circuit board 13a is substantially parallel to the interface 10. Furthermore, the at least one radiation source device 5 and the at least one detection device 7 are substantially parallel to the circuit board 13a.

[0057] According to one embodiment, at least one first aperture device is provided, which spatially limits the electromagnetic radiation 6 directed onto the interface 10. Alternatively or cumulatively, at least one second aperture device can be provided, which spatially limits the reflected electromagnetic radiation 8. In Fig. 12 shows an embodiment which is essentially the same as the embodiment according to Fig. 11. Furthermore, a third aperture device 16 is provided, which is a combination of a first aperture device and a second aperture device. The third aperture device 16 thus spatially limits both the electromagnetic radiation 6 directed onto the interface 10 and the reflected electromagnetic radiation 8. In the present case, the third aperture device 16 is V-shaped and is arranged on or near the prism 12 and between at least one radiation source device 5 and the at least one detection device 7.

[0058] In Fig. 13 shows an embodiment which essentially corresponds to the embodiment according to Fig. 11. Furthermore, a first window element 17 is arranged between the at least one radiation source device 5 and the interface 10. Alternatively or cumulatively, an additional second window element 18 can be arranged between the interface 10 and the at least one detection device 7. It would also be conceivable for the two window elements 17, 18 to be combined into one element. Fig. 13 shows such a combined element. It is V-shaped and is arranged on or near the prism 12 and between at least one radiation source device 5 and the at least one detection device 7.

[0059] In Fig. 14 shows an embodiment which is essentially the same as the embodiment according to Fig. 11. Furthermore, a first optical element 19 is arranged on or near the at least one radiation source device 5. Alternatively or additionally, a second optical element 20 can be arranged on or near the at least one detection device 7. The first optical element 19 and / or the second optical element 20 can be, for example, a prism or a lens.

[0060] The reflection element 9 can be designed in a variety of ways. The reflection element 9 can, for example, have several sections 9a, 9b, which are made of different materials. This is Fig. 16. A first section 9a consists of a first material and a second section 9b consists of a second material. According to the embodiment according to Fig. 17, the reflection element 9 has a rounding which is opposite the boundary surface 10.

[0061] According to the embodiment according to Fig. 18, the reflection element 9 has an additional interface 23, which, however, is not in contact with the fluid in the container 3, be it air or liquid. Rather, this additional interface 23 is arranged opposite the interface 10. Accordingly, several reflections of the electromagnetic radiation 6 can occur in the reflection element 9 before it exits the reflection element 9.

[0062] According to the embodiment according to the Fig. 19 and Fig. 20, the reflection element 9 has an edge region 24 consisting of a plurality of segments 25. These segments 25 are preferably angular in shape. The edge region is, of course, transparent to the electromagnetic radiation 6, 8.

[0063] According to one embodiment, at least one radiation guiding device 21 is provided. The electromagnetic radiation 6 of the at least one radiation source device 21 is guided in sections in the radiation guiding device 21. Alternatively or cumulatively, the electromagnetic radiation 8 reflected at the interface is guided in sections in the radiation guiding device 21. In Fig. 21, for example, a radiation guidance device 21 is provided. In this radiation guidance device 21, electromagnetic radiation 6 from one radiation source device 5 is guided along a section of the beam path, in this case the vertical section.

[0064] According to the embodiment according to the Fig. 21, a radiation guidance device 21 is provided. The radiation guidance device 21 is rod-shaped, arranged above the radiation source device 5, and substantially perpendicular to the radiation source device 5 or the circuit board 13a. The radiation guidance device 21 has a distal end 26, wherein the surfaces 26a of the distal ends 26 are each beveled by 45 degrees to a longitudinal direction X1 of the radiation guidance device 21. The first electromagnetic radiation 6 propagating in the longitudinal direction X1 in the radiation guidance device 21 is deflected, preferably by 90 degrees, by total reflection at the first surface 26a of the first distal end 26 of the radiation guidance device 21 and guided to the interface 10. The reflected electromagnetic radiation 8 is directed directly to the at least one detection device 7.In this embodiment, two circuit boards 13a are provided, wherein the at least one radiation source device 5 and the at least one detection device 7 are each arranged on a different circuit board.

[0065] According to the embodiment according to Fig. 22, a plurality of containers 3 are provided for storing a liquid. Only one radiation source device 5 is provided. Furthermore, a plurality of radiation conducting devices 21 are provided, which conduct electromagnetic radiation 6 of the radiation source device 5 to the respective interfaces 10 of the containers 3. In the present case, two containers 3 and two radiation conducting devices 21 are provided. The two containers are arranged essentially opposite one another along a width axis Y1. The radiation conducting devices 21 are arranged above the only one radiation source device 5 and essentially perpendicular to the radiation source device 5 or the circuit board 13a. The radiation conducting devices 21 are analogous to the embodiment according to Fig. 21. However, the radiation guidance devices 21 are arranged side by side such that the surfaces 26a of the distal ends 26 are opposite each other. The electromagnetic radiation of the two radiation guidance devices 21 is thus directed in opposite directions along the width axis Y1. Furthermore, a plurality of detection devices 7 are provided. Each container 3 is assigned a detection device 7. The reflected electromagnetic radiation is thus guided from the interface 10 of each container to the respectively assigned detection device 7.

[0066] In Fig.Figure 23 schematically illustrates a household appliance 2 with a system 1 for storing liquids. The household appliance further comprises a control device 27, which controls the at least one radiation source device 5 and receives and processes the sensor data from the at least one detection device 7. Depending on the detected fill level, a display device 28 could, for example, be controlled.

[0067] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are novel, individually or in combination, over the prior art. It is further noted that the individual figures also describe features that may be advantageous in and of themselves. The skilled person will immediately recognize that a specific feature described in a figure may be advantageous even without adopting further features from that figure. Furthermore, the skilled person will recognize that advantages may also arise from a combination of several features shown in individual or different figures. List of reference symbols 1 system 2 household appliances 3 containers 4 Level measuring device 5 Radiation source device 5a Radiation source 5b bent wire connections 6 emitted electromagnetic radiation 6a central beam direction of the emitted electromagnetic radiation 7 Detection device 7a Sensor element 7b bent wire connections 8 reflected electromagnetic radiation 8a central beam direction of the reflected electromagnetic radiation 9 Reflection element 9a first section of the reflection element 9b second section of the reflection element 10 Interface 11 Outer wall of the container 11a lower outer wall 11b side outer wall 12 optical prism 12a first side surface of the optical prism 12b second side surface of the optical prism 12c third side surface of the optical prism 13 Carrier device 13a plate-like element / board 13b curved board 13c flexible board 14 first section of the board 15 second section of the board 16 Aperture device 17 first window element 18 second window element 19 first optical element 20 second optical element 21 Radiation conduction device 22 fictitious plane parallel to the level of the liquid 23 additional interface 24 Marginal area 25 segments 26 distal ends of the radiation conduction device 26a Surfaces of the distal ends 27 Control device 28 Display device α angle of incidence α T critical angle β E Emission angle of the radiation source device β A Acceptance angle of the detection device γ angle between first section and second section of the board θ Angle between window element and liquid level ξ Angle between the emitted electromagnetic radiation and the second side surface ϕ S Angle between central beam direction of at least one radiation source device and circuit board Φ D Angle between the central beam direction of the at least one detection device and the circuit board X Longitudinal axis of the container Y width axis of the container Z Height axis of the container X' Longitudinal axis of the prism Y' latitude axis of the prism Z' height axis of the prism

Claims

[1] System (1) for storing liquids, in particular for a household appliance (2), comprising at least one container (3) for storing a liquid and at least one level measuring device (4), characterized by in that the fill level measuring device (4) comprises at least one radiation source device (5) which emits electromagnetic radiation (6) and at least one detection device (7) for electromagnetic radiation (8), wherein the at least one container (3) has a reflection element (9) which has only one interface (10) with a fluid located in the container (3). [2] System (1) according to claim 1 characterized bythat the electromagnetic radiation (6) of the at least one radiation source device (5) at a predetermined angle of incidence α or a predetermined angle of incidence range onto the interface (10), wherein in a first state of the system the container (3) is not filled with the liquid, wherein the fluid is air, wherein in the first state at least a portion of the electromagnetic radiation (6) is totally reflected at the only one interface and is detected by the at least one detection device. [3] System (1) according to one of claims 1 or 2 characterized by in that the reflection element (9) is arranged in or on an outer wall (11) of the at least one container (3), wherein the interface (10) is planar, curved, parabolic or designed as a spherical segment, wherein an optical element is integrated into the interface (10), wherein the reflection element consists of glass or a polymer. [4] System (1) according to one of the preceding claims characterized by in that the reflection element (9) comprises an optical prism (12), wherein a first side surface (12a) of the optical prism (12) forms only one interface (10) with a fluid located in the container (3). [5] System (1) according to one of claims 2 to 4 characterized by that the reflection element (9) is arranged on or in the outer wall (11) of the at least one container (3) in such a way that the boundary surface (10) runs obliquely to a fictitious plane (22) which is parallel to a level of the liquid in the container. [6] System (1) according to one of claims 2 to 4 characterized by that the reflection element (9) is arranged on or in the outer wall (11) of the at least one container (3) in such a way that the interface (10) is substantially parallel to a level of the liquid in the container. [7] System (1) according to one of the preceding claims characterized by in that the radiation source device (5) comprises at least one radiation source (5a), wherein the at least one radiation source (5a) is an LED, a laser, or a superluminescent diode (SLED), wherein the at least one radiation source device (5) and the at least one detection device (7) are arranged on a common carrier device (13), wherein the carrier device (13) comprises at least one plate-like element (13a), wherein the plate-like element (13) is a circuit board. [8] System (1) according to claim 7 characterized bythat the at least one radiation source device (5) and the at least one detection device (7) are assigned a central beam direction (6a, 8a), wherein the central beam direction (6a) of the at least one radiation source device (5) and / or the central beam direction (8a) of the at least one detection device (7) does not extend perpendicular to the plate-like element (13a), [9] System (1) according to claim 8 characterized by in that the at least one radiation source device (5) has at least one radiation source (5a) which is designed as a component with bent wire connections (5b), wherein the at least one detection device (7) has a sensor element (7a) which is designed as a component with bent wire connections (7b). [10] System (1) according to claim 6 to 8 characterized byin that the carrier device (13) comprises a curved circuit board (13b) or a flexible circuit board (13c), wherein the circuit board (13b, 13c) has a first section (14) on or at which the at least one radiation source device (5) is arranged, wherein the circuit board (13b, 13c) has a second section (15) on or at which the at least one detection device (7) is arranged, wherein the first section (14) and the second section (15) enclose an angle (γ), wherein the angle (γ) is less than 180°. [11] System (1) according to one of the preceding claims characterized by that the at least one radiation source device (5) has an emission angle (β E ) and the at least one detection device (7) has an acceptance angle (β A), wherein the at least one radiation source device (5) is arranged relative to the interface (10) in such a way that only a part of the electromagnetic radiation (6) is within the emission angle (β E ) strikes the interface (10), wherein the at least one detection device (7) is arranged relative to the interface (10) in such a way that only a part of the reflected electromagnetic radiation (8) is within the acceptance angle (β A ), wherein the at least one radiation source device (5) is approximately a Lambert radiator and the at least one detection device (7) is approximately a Lambert detector, wherein half the emission angle (β E ) is greater than or equal to 45°, where half the acceptance angle (β A ) is greater than or equal to 45°. [12] System (1) according to claim 10 characterized bythat at least one first aperture device is provided which spatially limits the electromagnetic radiation (6) directed onto the boundary surface (10), wherein at least one second aperture device is provided which spatially limits the reflected electromagnetic radiation (8). [13] System (1) according to one of the preceding claims characterized by that a first window element (17) is arranged between the at least one radiation source device (5) and the interface (10), wherein a second window element (18) is arranged between the interface (10) and the at least one detection device (7). [14] System (1) according to one of the preceding claims characterized byin that a first optical element (19) is arranged on or near the at least one radiation source device (5), wherein a second optical element (20) is arranged on or near the at least one detection device (7), wherein the first optical element (19) and / or the second optical element (20) is a prism or a lens. [15] System (1) according to one of the preceding claims characterized by that at least one radiation guidance device (21) is provided, wherein the electromagnetic radiation (6) of the at least one radiation source device (21) is guided in sections in the radiation guidance device (21), wherein the electromagnetic radiation (8) reflected at the interface is guided in sections in the radiation guidance device (21). [16] System (1) according to one of claims 1 to 5 characterized bythat a plurality of containers (3) are provided for storing a liquid, wherein only one radiation source device (5) is provided, wherein a plurality of radiation conducting devices (21) are provided which conduct electromagnetic radiation (6) of the radiation source device (5) to the respective boundary surfaces (10) of the containers (3), wherein a plurality of detection devices (7) are provided, wherein each container (3) is assigned a detection device (7). [17] Household appliance (2) with a system (1) for storing liquids according to one of the preceding claims.

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