System for storing liquid

Abstract

The invention relates to a system for storing a liquid, in particular for a household appliance, comprising at least one container for storing a liquid and at least one liquid level measuring device, the liquid level measuring device comprises at least one radiation source device emitting electromagnetic radiation and at least one detection device for the electromagnetic radiation, and the at least one container is provided with a reflecting element which has only one boundary surface with the fluid located in the container.

Description

Technical Field

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

[0002] Many devices and arrangements, in particular household appliances, comprise containers for storing various liquids. The corresponding household appliance may be a household appliance loaded with water, such as a dishwasher or a washing machine. Detergent, rinse aid or other treatment agents may be stored in at least one container. However, it is also conceivable that the container may be a storage device for condensed water in a household appliance, such as a refrigerator or a dryer. It is often necessary to obtain information about the filling level of such a container. Such information can be used to indicate the need for filling or emptying. Summary of the invention

[0003] The object of the present invention is to provide a system for storing liquids which makes it particularly easy to determine the filling level.

[0004] This problem is solved by the technical solution of claim 1. The dependent claims contain preferred embodiments.

[0005] According to the present invention, a system for storing liquids, in particular for household appliances, is provided, the system comprising at least one container for storing liquids and at least one liquid level measuring device, wherein the liquid level measuring device comprises at least one radiation source device emitting electromagnetic radiation and at least one detection device for electromagnetic radiation, wherein at least one container has a reflective element having only one boundary surface with the fluid located in the container.

[0006] If electromagnetic radiation hits a boundary surface between materials with different refractive indices, some of the radiation is reflected and some enters the adjacent material. This behavior depends on the so-called angle of incidence α of the electromagnetic radiation. In geometric optics, the angle of incidence α is the angle between the ray and the horizon / interface, which can reach up to 90°. When a beam of light passes through an optical boundary surface, its angle of incidence is the angle of incidence relative to the normal to that surface. If the angle of incidence α is greater than the critical angle α T , then total reflection of the radiation occurs. Therefore, the radiation is completely reflected. Critical angle α T The definition is as follows:

[0007]

[0008] Among them, n 1 and n 2 is the refractive index of the adjacent material. Preferably, n 1 is the refractive index of air or fluid. Advantageously, the refractive index of air n空气 Smaller than the refractive index n of the fluid 流体 (n 空气 <n 流体 ). Preferably, n 2 is the refractive index of the material of the reflective element. Preferably, the critical angle α of the electromagnetic radiation from the at least one radiation source device is T Determined by the refractive index n of the reflective element.

[0009] Preferably, the electromagnetic radiation from the at least one radiation source device hits the boundary surface at a predetermined angle of incidence α or a predetermined range of angles of incidence. In an advantageous first state of the system, the container is not filled with liquid. Therefore, the fluid in the container is preferably air. In the first state of the system, the reflective element therefore preferably has a boundary surface with air. In an advantageous second state of the system, the container is filled with fluid. Therefore, the fluid in the container is preferably a corresponding liquid. In the second state of the system, the reflective element therefore preferably has a boundary surface 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 boundary surface. Preferably, the reflected portion is detected by at least one detection device. Advantageously, in the second state, at a predetermined angle of incidence α, there is no total reflection of the electromagnetic radiation emitted by the at least one radiation source device from the only one boundary surface to be emitted.

[0010] In the system according to the invention, only one boundary surface with the fluid is provided in the container, at which total reflection occurs. Compared to other conceivable embodiments with two adjacent boundary surfaces enclosing a predetermined angle, the system according to the invention requires significantly less design effort for the at least one container.

[0011] According to a preferred embodiment, the reflective element is arranged in or on the outer wall of the container. Preferably, the boundary surface of the reflective element is planar. The plane boundary surface extends flatly or planarly without bending or the like. According to another possible embodiment, the boundary surface is curved, parabolic or in the form of a spherical segment. According to another aspect, the optical element can be integrated into the boundary surface. Such an optical element can be, for example, a lens. Advantageously, the reflective element comprises a material transparent to the electromagnetic radiation emitted by the at least one radiation source device. Preferably, the reflective element is made of glass or a polymer, for example polymethyl methacrylate (PMMA, also acrylic glass). Preferably, the reflective element can also have a plurality of parts made of different materials.

[0012] According to another preferred embodiment, the at least one container is a hollow body, the shape of the hollow body is substantially rectangular or square. However, other shapes, such as a body with a polygonal or circular bottom, are also conceivable. 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 horizontal plane or upper surface. The horizontal plane extends substantially in a plane spanned by the longitudinal axis X and the width axis Y. However, the orientation of the horizontal plane depends on the installation of the at least one container in the household appliance, or on the orientation of the container relative to the gravity acting on it.

[0013] According to another preferred embodiment, the reflective element comprises an optical prism. Advantageously, the first side surface of the optical prism forms only one boundary surface with the fluid present in the container. The prism can be a prism of any shape. Preferably, the first side surface forming the boundary surface is planar. The prism can preferably have interruptions along its length. The prism can preferably contain optically active structures, such as lens elements and / or surface roughness that supports scattering.

[0014] According to a preferred embodiment, the optical prism has a right prism with a triangular base. Such a prism preferably comprises a first side surface, a second side surface and a third side surface. Preferably, the electromagnetic radiation emitted from the at least one radiation source device enters the optical prism through the second side surface of the optical prism and reaches the first side surface or boundary surface of the optical prism. In the first state, at least a part of the electromagnetic radiation is totally reflected at the boundary surface and then leaves the optical prism through the third side surface. From there, the reflected radiation advantageously reaches the at least one detection device.

[0015] According to another advantageous embodiment, the reflective element is arranged on or in the outer wall of the at least one container such that the boundary surface is inclined or angled relative to an imaginary plane parallel to the liquid level. Preferably, the reflective element is arranged on or in the outer wall of the at least one container such that the boundary surface forms an angle θ with the imaginary plane parallel to the liquid level. Preferably, the angle θ is less than 180°.

[0016] According to another advantageous embodiment, the reflective element is arranged on or in the outer wall of at least one container so that the boundary surface is substantially parallel to the 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.

[0017] According to a preferred embodiment, the reflective element comprises a window element, which in turn comprises a boundary surface. Preferably, the window element is integrated in the outer wall of the at least one container. The window element may be planar, curved, parabolic or in the form of a spherical segment.

[0018] According to another 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. Of course, other suitable radiation sources are also conceivable. Preferably, the electromagnetic radiation emitted by the radiation source device has a wavelength λ in the range between about 300nm and about 1400nm. 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 device has emitted polarized electromagnetic radiation. Alternatively, the radiation source device may include at least one polarizer. According to another preferred embodiment, the electromagnetic radiation emitted by the at least one radiation source device is non-polarized. In this case, although the reflectivity below the critical angle will depend on the polarization direction, the critical angle is the same for different polarization angles.

[0019] 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 may be, for example, a phototransistor.

[0020] According to another advantageous embodiment, the at least one radiation source device and the at least one detection device are arranged on a common carrier device. Preferably, the carrier device comprises at least one plate-like element. Preferably, the plate-like element is a card, a circuit board or a PCB (printed circuit board). It is conceivable that the carrier device comprises a housing in which the at least one plate-like element is arranged.

[0021] According to another advantageous embodiment, a central beam direction is assigned to the at least one radiation source device and the at least one detection device. The at least one radiation source device has an emission angle β E . Emission angle β E describes a region into which electromagnetic radiation propagates from at least one radiation source device. Preferably, the emission of the at least one radiation source device is not isotropically distributed within an emission angle. In the case of a radiation source device in the form of an LED, a variety of emission behaviors are possible. This emission behavior can be petal-shaped, have a so-called batwing characteristic or have a side emission characteristic. Of course, other characteristics are also conceivable. Preferably, the at least one detection device has a reception angle β A . Acceptance angle β A The range in which the electromagnetic radiation propagates to the at least one detection device is described. Preferably, the detection efficiency of the at least one detection device is not isotropic within the acceptance angle. Therefore, the central beam direction of the at least one detection device will extend along the central height axis of the cone.

[0022] 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 perpendicularly to the plate-like element of the carrier device. The central beam direction of the at least one radiation source device (the central beam direction is not perpendicular to the plate-like element of the carrier device) can preferably be realized by at least one radiation source device with at least one radiation source (the at least one radiation source is designed as a component with a bent wire connection). Alternatively or cumulatively, the at least one radiation source can be an SMD LED (surface mounted LED) with an inclined optical axis or a side-view LED.

[0023] The central beam direction of the at least one detection device which is not perpendicular to the plate-shaped element of the carrier device can preferably be achieved by at least one detection device having a sensor element which is designed as a component with a bent wire connection. Preferably, the wire connections of the radiation source and / or the sensor element are arranged on the circuit board by through-hole mounting (also called through-hole technology THT).

[0024] According to another preferred embodiment, the carrier device comprises a curved plate. Preferably, such a curved plate is mechanically stable. According to another aspect, the carrier device can comprise a flexible plate. Preferably, the plate comprises a first section, on which the at least one radiation source device is arranged or at which the first section is arranged. Furthermore, it is advantageous that the plate has a second section, on which the at least one detection device is arranged or at which the second section is arranged. Preferably, the first section and the second section form an angle γ. Preferably, the angle γ is less than 180°. By means of a curved or flexible plate, this advantageous design in which the two parts enclose the angle γ can be achieved.

[0025] According to another preferred embodiment, the at least one radiation source device has an emission angle β E , and the at least one detection device has a receiving angle β A Preferably, the at least one radiation source device is arranged relative to the boundary surface so that at an emission angle β E Preferably, at least one acceptance angle of the detection device is arranged relative to the boundary surface so that at least a part of the reflected electromagnetic radiation is reflected at the acceptance angle β A Inside.

[0026] According to another preferred embodiment, the at least one radiation source device is arranged relative to the boundary surface so that at an emission angle β E Preferably, the at least one radiation source device has a large emission angle β EPreferably, the at least one radiation source arrangement is approximately a Lambertian radiator. Preferably, the at least one radiation source arrangement has at least one radiation source approximately a Lambertian radiator. A Lambertian radiator follows the Lambert cosine law, which states that from an angle θ L The observed radiation intensity (relative to the surface normal) is related to cos(θ L ). Preferably, the emission of the at least one radiation source device is not isotropically distributed within the emission angle. By such a design, the at least one radiation source device can be attached to the circuit board in a manner substantially parallel to the circuit board. Preferably, the proportion of the electromagnetic radiation impinging on the boundary surface is sufficient to achieve adequate detection.

[0027] Preferably, the at least one detection device is arranged relative to the boundary surface in such a way that only a portion of the reflected electromagnetic radiation is located within the reception angle β A Preferably, the at least one detection device has a large receiving angle β A . Preferably, the at least one detection device is approximately a Lambertian detector. Such a Lambertian detector is defined analogously to the above-described Lambertian radiator. Preferably, the at least one detection device has at least one sensor element, which is approximately a Lambertian detector. With such an embodiment, the at least one detection device can be attached to the circuit board in a manner essentially parallel to the circuit board. Preferably, the proportion of the electromagnetic radiation impinging on the at least one detection device is sufficient to achieve sufficient detection.

[0028] Preferably, the at least one radiation source device is approximately a Lambertian radiator and the at least one detection device is approximately a Lambertian detector.

[0029] Preferably, the emission angle (β E ) is greater than or equal to 45°. Preferably, the acceptance angle (β A ) is greater than or equal to 45°. Advantageously, the emission angle (β E ) and the receiving angle (β A ) should be understood similarly to the definition of aperture angle in the definition of numerical aperture. This aperture angle of an optical system preferably corresponds to the maximum possible angle of a light beam emitted from the object in question and just picked up by the lens. The aperture angle indicates how big the maximum cone of light captured by the lens from the object is.

[0030] According to another preferred embodiment, at least one first aperture device is provided, which spatially limits the electromagnetic radiation directed onto the boundary surface. Preferably, at least one second aperture device is provided, which spatially limits the reflected electromagnetic radiation. It is also conceivable that at least one third aperture device is provided, which both spatially limits the electromagnetic radiation directed onto the boundary surface and spatially limits the reflected electromagnetic radiation. Preferably, the at least one first aperture device and / or the at least one second aperture device and / or the at least one third aperture device are designed as pinhole apertures or slit apertures. If a lens having a large emission angle β is used, the at least one second aperture device and / or the at least one third aperture device are preferably designed as pinhole apertures or slit apertures. E By using a radiation source device, irradiation in undesired areas can be prevented. Undesired irradiation from reflected radiation can also be avoided.

[0031] According to another preferred embodiment, a first window element is arranged between said at least one radiation source arrangement and said boundary surface.Preferably, a second window element is arranged between said boundary surface and said at least one detection arrangement.

[0032] According to another preferred embodiment, the first optical element is arranged on or near the at least one radiation source device. Preferably, the 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.

[0033] According to another advantageous embodiment, at least one radiation guiding device is provided. Preferably, the electromagnetic radiation of the at least one radiation source device is guided in a section in the radiation guiding device. Preferably, the electromagnetic radiation reflected at the boundary surface is guided in a section of the radiation guiding device. Preferably, the radiation source device is rod-shaped and comprises an inclined distal end. Preferably, the electromagnetic radiation passing through the radiation source device is totally reflected at the inclined distal end and redirected to the boundary surface. Preferably, the electromagnetic radiation reflected at the boundary surface is totally reflected at the inclined distal end and guided to the radiation source device.

[0034] According to another advantageous embodiment, a plurality of containers are provided for storing liquid. Advantageously, only one radiation source device is provided. Preferably, a plurality of radiation guide devices are provided, which guide the electromagnetic radiation of the radiation source device to the respective boundary surfaces of the container. Advantageously, a plurality of detection devices are provided. Preferably, a detection device is assigned to each container.

[0035] It should be understood that the above embodiments can be combined as needed. Therefore, the at least one radiation source device of one embodiment can be combined with the at least one detection device of another embodiment.

[0036] The object is also achieved by a household appliance having a system for storing liquids.The household appliance can be equipped with all the above features described as part of the system, either individually or in combination with one another, and vice versa.

[0037] According to a particularly preferred embodiment, the system for storing liquid is part of the dispensing device. Preferably, the household appliance is a water-carrying household appliance, such as a dishwasher or a washing machine. Preferably, the liquid stored in the at least one container is a treatment agent, such as a detergent, a rinse aid, a rinse aid or a fabric softener or the like. Preferably, the at least one container is removable from the dispensing device.

[0038] Preferably, the household appliance is a dryer, wherein the container is used to store condensed water from the dryer.The system for storing liquids can be used, for example, to determine where a container needs to be emptied. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further advantages, objects and features of the invention are explained in the following description with reference to the accompanying drawings.In various embodiments, similar components may have the same reference numerals.

[0040] The figure shows:

[0041] Figure 1 is a side view of a system according to one embodiment;

[0042] Figure 2 is a perspective view of a system according to one embodiment;

[0043] Figure 3 is a side view of a system according to one embodiment;

[0044] Figure 4 is a perspective view of a system according to one embodiment;

[0045] Figure 5 a cross-sectional view of an arrangement of a system according to one embodiment;

[0046] Figure 5 a cross-sectional view of an arrangement of a system according to one embodiment;

[0047] Figure 6 A system according to an unfavorable embodiment;

[0048] Figure 7 It is a schematic comparison of an unfavorable design and a favorable design;

[0049] Figure 8 is the reflectivity measurement curve as a function of the angle of incidence;

[0050] Fig. 9 a cross-sectional view of an arrangement of a system according to another embodiment;

[0051] Fig.10 is a cross-sectional view of an arrangement of a system according to another embodiment;

[0052] Fig.11 a cross-sectional view of an arrangement of a system according to another embodiment;

[0053] Fig.12 a cross-sectional view of an arrangement of a system according to another embodiment;

[0054] Fig.13 a cross-sectional view of an arrangement of a system according to another embodiment;

[0055] Fig.14 a cross-sectional view of an arrangement of a system according to another embodiment;

[0056] Fig.15 a cross-sectional view of an arrangement of a system according to another embodiment;

[0057] Fig.16 a cross-sectional view of an arrangement of a system according to another embodiment;

[0058] Fig.17 a cross-sectional view of an arrangement of a system according to another embodiment;

[0059] Fig.18 a cross-sectional view of an arrangement of a system according to another embodiment;

[0060] Fig.19 a cross-sectional view of an arrangement of a system according to another embodiment;

[0061] Fig. 20 a cross-sectional view of an arrangement of a system according to another embodiment;

[0062] Fig.21 a cross-sectional view of an arrangement of a system according to another embodiment;

[0063] Fig. 22 a cross-sectional view of an arrangement of a system according to another embodiment, and

[0064] Fig.23 is a schematic diagram of a household appliance according to one embodiment. DETAILED DESCRIPTION

[0065] Figure 1-Figure 5 and Figure 9-Figure 22A 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 liquids and at least one liquid level measuring device 4, wherein the liquid level measuring device comprises at least one radiation source device 5 emitting electromagnetic radiation 6 and at least one detection device 7 for electromagnetic radiation 8, wherein the at least one container 3 has a reflective element 9 having only one boundary surface 10 with the fluid located in the container 3.

[0066] 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 substantially rectangular or square hollow body. However, other shapes are also conceivable, such as a body with a polygonal or circular bottom. The container 3 also includes an outer wall 11. If there is a liquid in the container 3, the liquid has a horizontal surface or upper surface. The horizontal surface extends substantially in a plane spanned by the longitudinal axis X and the width axis Y.

[0067] The reflective element 9 is arranged in or on the outer wall 11 of the at least one container 3. The boundary surface 10 can be planar, curved, parabolic or in the form of a spherical segment. According to an advantageous embodiment, optical elements can also be integrated into the boundary surface 10. The reflective element 6 can also be made of glass or polymer.

[0068] The electromagnetic radiation 6 of at least one radiation source device 5 strikes the boundary surface 10 at a predetermined angle of incidence α or at a predetermined range of angles of incidence. In a first state of the system, the container 3 is not filled with liquid. Therefore, the boundary surface is at the fluid air. Therefore, there is a transition from the material of the reflective element 9, such as glass or plexiglass, to air. Due to this transition, at least a portion of the electromagnetic radiation 6 striking the boundary surface at a predetermined angle of incidence α is totally reflected at only one boundary surface 10 in the first state of the system. The reflected electromagnetic radiation 8 is then detected by at least one detection device 7. In a second state of the system, the container 3 is filled with liquid. Therefore, in the second state of the system, there is a transition from the material of the reflective element 9, such as glass or plexiglass, to liquid. As a result of this transition, at a specified angle of incidence α, there is no total reflection of the electromagnetic radiation 6 at a single boundary surface 10. This lack of total reflection at a predetermined angle of incidence α can also be detected by at least one detection device 7. The boundary surface 10 can also be referred to as an optically active surface.

[0069] The reflective element 9 comprises an optical prism 12, the first side surface 12a of which forms only a boundary surface 10 with the fluid located in the container 3. The prism can have fundamentally different shapes; in the following, without limiting the generality, reference is made to a right prism with a triangular base. The emitted electromagnetic radiation 6 enters the prism 12 through the second side surface 12b and reaches the boundary surface 10 or the first side surface 12a. When the system is in the first state, the electromagnetic radiation 6 is totally reflected at the boundary surface 10 and then leaves the prism 12 as reflected electromagnetic radiation 8 through the third side surface 12c.

[0070] The radiation source device 5 comprises at least one radiation source 5a. The at least one radiation source 5a may be an LED, a laser or a super luminescent diode (SLED).

[0071] At least one radiation source device 5 and 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 is conceivable that the carrier device 13 comprises a housing (not shown in the figure) in which the at least one plate-like element 13a is arranged.

[0072] Figure 6 An embodiment that is considered to be disadvantageous is shown. According to this embodiment, there are two boundary surfaces with the fluid (which can be air or liquid) in the container 3. The incident electromagnetic radiation 6 is reflected at the first boundary surface to the second boundary surface. The electromagnetic radiation is then reflected from the second boundary surface to the detection device. However, the invention currently claimed for protection has only one boundary surface for the fluid in the container. The embodiment according to the present invention has the advantageous advantage that a simpler construction of the structure of the container is possible. The geometry of the container can be simplified. If the internal structure of the container is disadvantageously more complicated, the stored liquid can more easily remain on the surface after emptying. The reason for this is the surface tension of the edges with an angle of less than 180°. Figure 7 The non-advantageous embodiment under a) is compared with embodiment b) of the present invention. Compared with the non-advantageous embodiment, the embodiment according to the present invention has more advantages in terms of tolerance. The non-advantageous embodiment a) has a translation tolerance of X'=0, Y'=2X and Z=0. In contrast, embodiment b) according to the present invention has a translation tolerance of X'=1.41(sqrt2), Y'=2X and Z=0. The non-advantageous embodiment a) has an angular tolerance of X'=4X', Y'=4X' and Z=4X'. In contrast, embodiment b) according to the present invention has an angular tolerance of X'=2X', Y'=2X' and Z=2X'. Therefore, the embodiment according to the present invention has better translation tolerance and better angular tolerance because total reflection occurs only at one boundary surface.

[0073] Figure 1 and Figure 2 An embodiment of the system is shown, wherein Figure 1 is a side view, Figure 2 1 and 2 are perspective views. As can be seen from these figures, the reflective element 9, such as a prism 12, is arranged in or on the outer wall 11 of the at least one container 3 so that the boundary surface 10 is inclined or extends obliquely relative to an imaginary plane 22, which is parallel to the horizontal plane of the liquid. Therefore, the boundary surface 10 and the imaginary plane 22 enclose an angle θ of less than 180°. The boundary surface 10 extends obliquely between the bottom outer wall 11a and the lateral outer wall 11b. Therefore, the boundary surface 10 is arranged substantially laterally on the lower area of ​​the container. The figure clearly shows that, due to the direction of the boundary surface 10, the corner part of the container has been replaced by the reflective element 9. The circuit board 13a (on which at least one radiation source device 5 and at least one detection device 7 are arranged) is arranged substantially parallel to the boundary surface 10.

[0074] Figure 3 and Figure 4 Another embodiment of the system is shown, wherein: Figure 3 is a side view, Figure 4 1 and 2 are perspective views. As can be seen from these figures, the reflective element 9 (e.g., prism 12) is arranged on or in the container 2 in such a way that the boundary surface 10 extends substantially parallel to an imaginary plane 22, which is parallel to the horizontal plane of the liquid. Therefore, the boundary surface 10 and the imaginary plane 22 enclose an angle θ, which is substantially 180°. The boundary surface 10 is arranged in or on the bottom outer wall 11a. The circuit board 13a (on which at least one radiation source device 5 and at least one detection device 7 are arranged) is arranged substantially parallel to the boundary surface 10.

[0075] Figure 5 A cross section is shown, in which a prism 12, a carrier device 13 with at least one radiation source device 5 and at least one detection device 7, and beam paths of emitted electromagnetic radiation 6 and reflected electromagnetic radiation 8 are shown. The angle ξ between the emitted electromagnetic radiation 6 and the second side surface 12b of the prism 12 can be 90°. However, other angles are also conceivable. The angle of incidence α depends on the respective material of the prism or the refractive index n of the material.

[0076] Figure 8 The reflectivity is shown as a function of the angle of incidence α (unpolarized radiation) for different materials of the reflective element 9. In diagram a), the refractive index of the material is n 1 =1.45. In Figure b), the refractive index of the material is n 1=1.65. In Figure c), the refractive index of the material is n 1 = 1.55. These figures also show the angular dependence of the total reflectivity in the unfilled state (the fluid at the boundary surface 10 is air) and the filled state (the fluid at the boundary surface 10 is liquid). In the unfilled state, when n 1 =1.45, the critical angle α T About 43°, when n 1 =1.65, the critical angle α T About 37°, when n 1 =1.5, the critical angle α T About 41°.

[0077] At least one radiation source device 5 has an emission angle β E . Emission angle β E describes the range of propagation of electromagnetic radiation 6 from at least one radiation source device 5. The at least one detection device has a reception angle β A . Acceptance angle β A A range is described in which the electromagnetic radiation propagates towards the at least one detection device. Furthermore, central beam directions 6a, 8a are assigned to at least one radiation source device 5 and at least one detection device 7.

[0078] The central beam direction 6a of the at least one radiation source device 5 and / or the central beam orientation 8a of the at least one detection device 7 preferably do not extend perpendicularly to the plate-like element 13a. This allows the electromagnetic radiation 6 to be incident at a predetermined angle of incidence α and the reflected electromagnetic radiation 8 to be detected only at one boundary surface 10.

[0079] Fig. 9 An embodiment is shown, in which neither the central beam direction 6a of the at least one radiation source device 5 nor the central beam orientation 8a of the at least one detection device 7 extends perpendicularly to the plate-like element 13a. Of course, embodiments can be envisaged in which only the at least one radiation source device 5 or the at least one detection device 7 has a central beam direction 6a, 8a that does not extend perpendicularly to the plate-like element 13a. In order to achieve such a central radiation direction 6a that does not extend perpendicularly 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 having a bent wire connection 5b: alternatively or cumulatively, the at least one detection device 7 can comprise a sensor element 7a, which is designed as a component having a bent wire connection 7b. The central beam direction 6a of the at least one radiation source device 5 and the circuit board 13a thus encloses an angle φ that is less than 90°. S The central beam direction 8a of the at least one detection device 7 and the circuit board 13a thus form an angle φ of less than 90°. D. The figure also clearly shows that the corresponding components are not parallel to the circuit board 13a and are therefore attached to the circuit board at a distance from the circuit board surface. The individual wire connections 5b, 7b are attached to the circuit board using through-hole technology. Another possible way of enabling at least one radiation source device 5 with a central beam direction 6a extending not perpendicularly to the plate-like element 13a is to use side-looking LEDs.

[0080] Fig.10 An embodiment is shown in which only the central beam direction 6a of at least one radiation source device 5 does not extend perpendicularly to the plate-like element 13a. The central beam direction 8a of the at least one detection device 7 extends substantially perpendicularly to the plate-like element 13a. According to this embodiment, the central beam direction 6a of the at least one radiation source device 5 is substantially parallel to the plate-like element 13a. Therefore, the angle φ S Basically 0 °. However, the arrangement of the plate-like element 13a relative to the container makes the boundary surface 10 extend at a certain angle thereto. Therefore, the angle between the plane where the boundary surface 10 is located and the plane where the plate-like element 13 is located is less than 90 ° and greater than 0 °, preferably, the angle is in the 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 a bent wire connection 5b. The radiation source 5a is not parallel to the circuit board 13a, and is therefore attached to the circuit board at a distance from the circuit board surface. Each wire connection 5b is attached to the circuit board by using through-hole technology.

[0081] Fig.15 An alternative embodiment is shown. Here, the circuit board 13, 13b, 13c has a first section 14, on which at least one radiation source device 5 is arranged or at which the first section is arranged. In addition, the board 13, 13b, 13c has a second section 15, on which at least one detection device 7 is arranged or at which the second section is arranged. The first section 14 and the second section 15 enclose an angle γ that is less than 180°. This structure is made possible by a curved board 13b or a flexible board 13c. The boards 13b, 13c are arranged relative to the container 3 so that the boundary surface 10 extends at an angle to both the first section 14 and the second section 15. The angle between the plane in which the boundary surface 10 is located and the plane in which the portion 15 is located is thus less than 90° and greater than 0°, preferably, the angle is in the range between 20° and 70°. Therefore, the at least one radiation source device 5 and the at least one detection device 7 can be arranged substantially parallel to the surface of the respective portion.

[0082] According to another embodiment, at least one radiation source device 5 is selected such that it has a large emission angle β EPreferably, the at least one radiation source device 5 is approximately a Lambert radiator. Alternatively or in addition, the at least one detection device 7 is selected such that it has a large acceptance angle β A Preferably, at least one detection device 7 is approximately a Lambertian detector. Fig.11 In the embodiment of the present invention, such a radiation source device 5 and such a detection device 7 are provided. At least one radiation source device 5 is arranged relative to the boundary surface 10 in such a way that at the emission angle β E In addition, at least one reception angle of the detection device 7 is arranged relative to the boundary surface 10 so that only a part of the reflected electromagnetic radiation 8 is reflected at the reception angle (β A ). Due to the large emission angle β E , sufficient electromagnetic radiation 6 strikes the boundary surface 10. Due to the large reception angle β A , sufficient reflected electromagnetic radiation 8 strikes the at least one detection device 7 to achieve effective detection. According to this embodiment, the circuit board 13a is substantially parallel to the boundary surface 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.

[0083] According to one embodiment, at least one first aperture device is provided, which spatially limits the electromagnetic radiation 6 directed onto the boundary surface 10. Alternatively or in addition, at least one second aperture device may be provided, which spatially limits the reflected electromagnetic radiation 8. Fig.12 shows a basically Fig.11 In the embodiment shown, a third aperture device 16 is provided, which is a combination of the first aperture device and the second aperture device. Thus, the third aperture device 16 spatially limits the electromagnetic radiation 6 directed onto the boundary surface 10 and the reflected electromagnetic radiation 8. In the present case, the third aperture device 16 is V-shaped and is arranged at or near the prism 12 and between the at least one radiation source device 5 and the at least one detection device 7.

[0084] Fig.13 shows a basically Fig.11 Furthermore, a first window element 17 is arranged between the at least one radiation source device 5 and the boundary surface 10. Alternatively or cumulatively, an additional second window element 18 can be arranged between the boundary surface 10 and the at least one detection device 7. It is also conceivable that the two window elements 17, 18 are combined to form one element. Fig.13 Such a combination element is shown. It is V-shaped and is arranged at or near the prism 12 and between the at least one radiation source device 5 and the at least one detection device 7.

[0085] Fig.14 shows a basically Fig.11 In addition, the first optical element 19 is arranged on or near the at least one radiation source device 5. Alternatively or cumulatively, the 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.

[0086] The reflective element 9 can be designed in many ways. For example, the reflective element 9 can have multiple parts 9a, 9b made of different materials. Fig.16 The first section 9a is made of a first material, and the second section 9b is made of a second material. Fig.17 In the illustrated embodiment, the reflective element 9 has a rounded portion / circular segment opposite the boundary surface 10 .

[0087] according to Fig.18 In the embodiment shown, the reflective element 9 has an additional interface 23, which, however, is not in contact with the fluid (whether air or liquid) in the container 3. Instead, the additional interface 23 is arranged opposite the boundary surface 10. Therefore, the electromagnetic radiation 6 may be reflected multiple times in the reflective element 9 before it is emitted from the reflective element 9.

[0088] according to Fig.19 and Fig. 20 In the embodiment shown, the reflective element 9 has a border region 24 which consists of a plurality of segments 25. Preferably, these segments 25 are angled. The border region is of course transparent to the electromagnetic radiation 6, 8.

[0089] According to one embodiment, at least one radiation guiding device 21 is provided. In this case, the electromagnetic radiation 6 of the at least one radiation source device 21 is guided in a section in the radiation guiding device 21. Alternatively or cumulatively, the electromagnetic radiation 8 reflected at the boundary surface is guided in a section in the radiation guiding device 21. For example, Fig.21 In the embodiment of the present invention, a radiation guiding device 21 is provided. In the radiation guiding device 21, electromagnetic radiation 6 from one radiation source device 5 is guided along a portion of the beam path, in this case the vertical portion.

[0090] according to Fig.21In the embodiment shown, a radiation guiding device 21 is provided. The radiation guiding 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 guiding device 21 has a distal end 26, wherein the surface 26a of the distal end 26 is each inclined 45 degrees relative to the longitudinal direction X1 of the radiation guiding device. The first electromagnetic radiation 6 propagating in the longitudinal direction X1 in the radiation guiding device 21 is preferably deflected 90 degrees by total reflection at the first surface 26a of the first distal end 26 of the radiation guiding device 21, and is guided to the boundary surface 10. The reflected electromagnetic radiation 8 travels directly to the at least one detection device 7. In the present embodiment, two circuit boards 13a are provided, wherein at least one radiation source device 5 and at least one detection device 7 are each arranged on different circuit boards.

[0091] according to Fig. 22 In the embodiment shown, a plurality of containers 3 are provided for storing liquid. Only one radiation source device 5 is provided. In addition, a plurality of radiation guide devices 21 are provided, which guide the electromagnetic radiation 6 of the radiation source device 5 to the corresponding boundary surfaces 10 of these containers 3. In this example, two containers 3 and two radiation guide devices 21 are provided. The two containers are arranged substantially opposite to each other along the width axis Y1. The radiation guide device 21 is arranged above only one radiation source device 5 and substantially perpendicular to the radiation source device or the circuit board 13a. The radiation guide device 21 is similar to the one according to Fig.21 Embodiment. However, the radiation guiding devices 21 are arranged adjacent to each other so that the surfaces 26a of the distal ends 26 are opposite to each other. The electromagnetic radiation of the two radiation guiding devices 21 is thus guided in opposite directions along the width axis Y1. In addition, a plurality of detection devices 7 are provided. The detection device 7 is assigned to each container 3. The reflected electromagnetic radiation is thus guided from the boundary surface 10 of each container to the corresponding assigned detection device 7.

[0092] Fig.23 Schematically shown is a household appliance 2 having a system 1 for storing liquids. The household appliance further has a control device 27 which controls the at least one radiation source device 5 and receives and processes sensor data from the at least one detection device 7. For example, depending on the detected filling level, a display device 28 can be controlled.

[0093] The applicant reserves the right to claim all features disclosed in the application documents that are important for the invention, provided that these features are new compared to the prior art, either individually or in combination. It should also be noted that the individual drawings also depict features that may be advantageous in themselves. A person skilled in the art immediately recognizes that a particular feature depicted in a drawing may also be advantageous without the further features of that drawing. Furthermore, a person skilled in the art recognizes that a combination of several features shown in a single drawing or in different drawings may also produce advantages.

[0094] Reference numerals list

[0095] 1 System

[0096] 2Household appliances

[0097] 3 Containers

[0098] 4 Liquid level measuring device

[0099] 5 Radiation source device

[0100] 5a Radiation Source

[0101] 5b Bent wire connector

[0102] 6Emitted electromagnetic radiation

[0103] 6a Direction of the central beam of emitted electromagnetic radiation

[0104] 7. Detection device

[0105] 7a Sensor element

[0106] 7b Bent wire connector

[0107] 8Reflected electromagnetic radiation

[0108] 8a Direction of the central beam of reflected electromagnetic radiation

[0109] 9Reflective elements

[0110] 9a First section of the reflective element

[0111] 9b Second section of the reflective element

[0112] 10 Boundary surface

[0113] 11 Container outer wall

[0114] 11a Bottom outer wall

[0115] 11b Transverse outer wall

[0116] 12 Optical prism

[0117] 12a First side of the optical prism

[0118] 12b Second side of the optical prism

[0119] 12c The third side of the optical prism

[0120] 13 Carrier device

[0121] 13a Plate-like element / plate

[0122] 13b Curved plate

[0123] 13c Flexible board

[0124] 14 First section of the board

[0125] 15 Second section of the plate

[0126] 16 Aperture device

[0127] 17 First window element

[0128] 18 Second window element

[0129] 19 First optical element

[0130] 20 Second optical element

[0131] 21 Radiation Guidance Device

[0132] 22 Imaginary plane parallel to the liquid surface

[0133] 23 Additional cross sections

[0134] 24 Boundary Area

[0135] 25 Segments

[0136] 26 Distal end of the radiation guide

[0137] 26a Distal surface

[0138] 27 Control Device

[0139] 28 Display device

[0140] αIncident Angle

[0141] α T Critical Angle

[0142] β E Emission angle of the radiation source device

[0143] β A Receiving angle of the detection device

[0144] The angle between the first and second segments of the gamma plate

[0145] θThe angle between the window element and the liquid level

[0146] ξAngle φ between the emitted electromagnetic radiation and the second side S Angle φ between the central beam direction of at least one radiation source device and the circuit board D Angle between the central beam direction of at least one detection device and the circuit board X longitudinal axis of the container

[0147] The width of the Y container

[0148] Z container height axis

[0149] X' is the longitudinal axis of the prism

[0150] Y' is the width axis of the prism

[0151] Z' is the height axis of the prism.

Claims

1. A system (1) for storing liquids, in particular for a household appliance (2), comprising at least one container (3) for storing liquids and at least one liquid level measuring device (4), characterized in that: The liquid level measuring device (4) comprises at least one radiation source device (5) for emitting electromagnetic radiation (6) and at least one detection device (7) for electromagnetic radiation (8), wherein the at least one container (3) has a reflecting element (9) which has only one boundary surface (10) with the fluid located in the container.

2. The system (1) according to claim 1, characterized in that The electromagnetic radiation (6) of the at least one radiation source device (5) is incident on the boundary surface (10) at a predetermined angle of incidence α or a predetermined range of angles of incidence, wherein, in a first state of the system, the container (3) is not filled with the liquid, wherein the fluid is air, and wherein, in the first state, at least a portion of the electromagnetic radiation (6) is totally reflected at the only one boundary surface and detected by the at least one detection device.

3. The system (1) according to claim 1 or 2, characterized in that The reflective element (9) is arranged in or on an outer wall (11) of the at least one container (3), wherein the boundary surface (10) is planar, curved, parabolic or in the form of a spherical segment, wherein an optical element is integrated into the boundary surface (10), wherein the reflective element consists of glass or a polymer.

4. System (1) according to any one of the preceding claims, characterized in that The reflective element (9) comprises an optical prism (12), wherein a first side surface (12a) of the optical prism (12) forms only one boundary surface (10) with the fluid in the container (3).

5. The system (1) according to any one of claims 2 to 4, characterized in that The reflective element (9) is arranged on or in the outer wall (11) of the at least one container (3) such that the boundary surface (10) extends obliquely relative to an imaginary plane (22) which is parallel to the horizontal plane of the liquid in the container.

6. The system (1) according to any one of claims 2 to 4, characterized in that The reflective element (9) is arranged on or in an outer wall (11) of the at least one container (3) such that the boundary surface (10) is substantially parallel to the horizontal plane of the liquid in the container.

7. System (1) according to any one of the preceding claims, characterized 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 (13a) is a circuit board.

8. The system (1) according to claim 7, characterized in that 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), 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) do not extend perpendicularly to the plate-like element (13a).

9. The system (1) according to claim 8, characterized in that The at least one radiation source device (5) comprises at least one radiation source (5a), which is designed as a component with a bent wire connection (5b), wherein the at least one detection device (7) comprises a sensor element (7a), which is designed as a component with a bent wire connection (7b).

10. System (1) according to claims 6 to 8, characterized in that The carrier device (13) comprises a curved plate (13b) or a flexible plate (13c), wherein the plate (13b, 13c) has a first section (14), the at least one radiation source device (5) is arranged on or at the first section, wherein the plate (13b, 13c) has a second section (15), and the at least one detection device (7) is arranged on or at the second section, 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 any one of the preceding claims, characterized in that The at least one radiation source device (5) has an emission angle (β E ), and the at least one detection device (7) has a receiving angle (β A ), wherein the at least one radiation source device (5) is arranged relative to the boundary surface (10) such that the emission angle (β E ) only a portion of the electromagnetic radiation (6) within the acceptance angle (β) impinges on the boundary surface (10), wherein the at least one detection device (7) is arranged relative to the boundary surface (10) in such a way that only a portion of the reflected electromagnetic radiation (8) is located within the acceptance angle (β) A ), wherein the at least one radiation source device (5) is approximately a Lambertian radiator, and the at least one detection device (7) is approximately a Lambertian detector, wherein the half emission angle (β E ) is greater than or equal to 45°, where the half acceptance angle (β A ) is greater than or equal to 45°.

12. The system (1) according to claim 10, characterized in that At least one first aperture device is provided, which spatially limits the electromagnetic radiation (6) directed onto the boundary surface (10); and at least one second aperture device is provided, which spatially limits the reflected electromagnetic radiation (8).

13. System (1) according to any one of the preceding claims, characterized in that A first window element (17) is arranged between the at least one radiation source device (5) and the boundary surface (10), wherein a second window element (18) is arranged between the boundary surface (10a) and the at least one detection device (7).

14. System (1) according to any one of the preceding claims, characterized in 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 any one of the preceding claims, characterized in that At least one radiation guiding device (21) is provided, wherein the electromagnetic radiation (6) of the at least one radiation source device is guided in a section of the radiation guiding device (21), wherein the electromagnetic radiation (8) reflected at the boundary surface is guided in a section of the radiation guiding device (21).

16. System (1) according to any one of claims 1 to 5, characterized in that A plurality of containers (3) for storing liquid are provided, wherein only one radiation source device (5) is provided, wherein a plurality of radiation guiding devices (21) are provided, the radiation guiding devices guiding electromagnetic radiation (6) from the radiation source device (5) to corresponding boundary surfaces (10) of the containers (3); a plurality of detection devices (7) are provided, wherein each container (3) is assigned one detection device (7).

17. A household appliance (2) comprising a system (1) for storing liquids according to any one of the preceding claims.

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