WO2009081308A2

WO2009081308A2 - Container having a space for containing a liquid, comprising means for indicating the level of the liquid

Info

Publication number: WO2009081308A2
Application number: PCT/IB2008/055225
Authority: WO
Inventors: Bart A. Salters; Marcellinus P. C. M. Krijn
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2007-12-18
Filing date: 2008-12-11
Publication date: 2009-07-02
Anticipated expiration: 2010-06-18
Also published as: DE202008016449U1; WO2009081308A3

Abstract

A container (2) comprises a space (4) for containing a liquid, a wall (5) encompassing the space (4), and means for indicating the level of the liquid in the container (2). At least a portion of the wall (5) of the container (2) is permeable to light, and the liquid level indicating means comprise a light source (10, 40) which is adapted to emit light below the surface (6) of the liquid in order to cause light emitted from below the surface (6) to reflect on the surface (6). The light source (10, 40) may comprise one or more lighting elements (10) arranged inside the space (4) of the container (2). Furthermore, the light source (10, 40) may comprise a light guide (40), wherein one or more lighting elements (10) are arranged at one end (41) of the light guide (40), and wherein at various positions, a surface of the light guide (40) is irregular for the purpose of letting light escape at those positions.

Description

Container having a space for containing a liquid, comprising means for indicating the level of the liquid

FIELD OF THE INVENTION

The present invention relates to a container comprising a space for containing a liquid, a wall encompassing the space, and means for indicating the level of the liquid in the container. The present invention also relates to a domestic appliance such as a coffeemaker, a water boiler or a steam iron, comprising a container as mentioned.

BACKGROUND OF THE INVENTION

A lot of products, in particular domestic appliances such as coffeemakers, water boilers and steam irons, comprise a container comprising a space for containing water, and a wall encompassing the space. In many cases, the wall of the container comprises a bottom portion and a standing, cylindrically-shaped portion extending from the circumference of the bottom portion. At a top side, the container may simply be open, or a lid or the like may be provided for closing the space of the container in a normal position, wherein the lid may temporarily be put to an opened position by a user for the purpose of supplying water to the space.

During their operation, the products as mentioned use water, as a result of which the quantity of water in the container decreases. In order to ensure proper functioning of the products, it is important that at least a minimum quantity of water is present in the container at any time during their operation. For the purpose of informing a user about the actual quantity of water present inside the space of a container at any given moment, the container is usually equipped with means for indicating the level of the water in the container. In a well-known embodiment, the water level indicating means comprise a small, floating element. However, major disadvantages of the application of such an element are that it does not provide a very accurate indication of the level of the water, and that it is hard to see. In another known embodiment, the level of the water is measured electronically, and is indicated by a series of light emitting diodes (LEDs). In such a case, there are no problems regarding visibility, however, this solution is very expensive. It is also possible that the container simply comprises a window, so that a user may check the level of the water through that window. However, also in this case, the level of the water is hard to see, especially when environmental lighting conditions are far from optimal, which is not inconceivable in a domestic environment such as a kitchen.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a container in which the liquid level indicating means are very well capable of providing an indication of the level of the liquid in the container which is clearly visible under all circumstances and most accurate, wherein the application of expensive components is not at all required. This object is achieved by a container comprising a space for containing a liquid, a wall encompassing the space, and means for indicating the level of the liquid in the container, wherein at least a portion of the wall of the container is permeable to light, and wherein the liquid level indicating means comprise a light source which is adapted to emit light below possible levels of the surface of the liquid in the container, in order to cause light emitted from below the surface to reflect on the surface. According to the present invention, a phenomenon known as total internal reflection is used for the purpose of lighting a quantity of liquid which is present inside the space of the container. This means that light traveling at relatively shallow angles with respect to a surface of a liquid cannot escape from the liquid, but will reflect on the surface of the liquid instead. In view of this, according to the present invention, a light source which is adapted to emit light below a surface of the liquid is applied. Preferably, the light source is furthermore adapted to emit light in directions which are horizontal and close to horizontal in a normal orientation of the container, i.e. at relatively shallow angles with respect to the surface of the liquid, so that as much as possible of the light will reflect on this surface. As a result, when the light source is activated, the surface of the liquid is clearly visible through the translucent portion of the wall of the container, as this surface is at a transition between an illuminated content of the container and a darker content of the container. In particular, due to the total internal reflection process, there is a lot of light in the liquid just below the surface of the liquid, while there is hardly any light above this surface, so that the transition is really a sharp transition. For the sake of completeness, it is noted that a normal orientation of the container may be understood as being an operational orientation in which the container is intended to be used (?) in an appliance of which it is part.

It follows from the foregoing explanation of the present invention that a most accurate process of indicating the level of the liquid which is present inside the space of the container is realized, as the liquid itself is applied both as a measurement tool and as an indicating tool. The level of the liquid is clearly visible to a user, not only by simply having a window in the wall of the container, but by illuminating the quantity of liquid as well, in such a way that light emitted from below the surface of the liquid is reflected on the surface of the liquid and cannot escape through this surface. It is easy for the user to notice a transition between the quantity of liquid which appears to be brightly shining and a darker environment, even from a large distance. Also, it is possible to check the level of the liquid in a dark environment.

The above-described process of indicating the level of the liquid which is present inside the space of the container by introducing light into the liquid, and by making sure that a total internal reflection process takes place at the surface of the liquid by introducing the light below this surface, may be achieved by means of various constructional measures. For example, one or more LEDs operating at very low and thus safe voltages, for example, a voltage of approximately 2.5 Volts, may be used. Such LEDs may simply be mounted below the level of the liquid, inside the space of the container. In general, it is true that at least a portion of the light source may be arranged inside the space of the container. Preferably, the light source is adapted to emit light only in a limited range of directions, in particular in directions which are sideward in a normal orientation of the container, so that practically all of the light is emitted at relatively shallow angles with respect to the surface of the liquid during operation of the light source, in view of the fact that the surface of the liquid (always) has a horizontal orientation, and an optimal total internal reflection process may be obtained.

The best results in respect of lighting the liquid and achieving that the liquid is significantly brighter than its immediate surroundings are obtained when light is emitted just below the surface of the liquid. In this respect, it is advantageous if it is possible for the light source to stay close to the surface of the liquid under all circumstances. This may actually be achieved by letting the light source follow the varying level of the surface of the liquid. For example, the light source may be connected to a floating member which is very well capable of following the level. In such a case, the light source is connected to the floating member at a side of the floating member which constitutes a bottom side in a normal orientation of the container, so that it is ensured that the light source is always below the surface of the water. In a specific, practical embodiment of the container, a so-called light guide is applied, which is a piece of material which is permeable to light. For example, the light guide may simply be a strip of translucent plastic. Furthermore, in this embodiment, at least one element for generating light is applied, wherein this lighting element is arranged at an end of the light guide, and wherein this lighting element is adapted to emit light to the interior of the light guide, at relatively shallow angles with respect to a surface of the light guide in order to reflect on this surface. A further aspect of this embodiment is that a surface of the light guide is a substantially planar surface which comprises portions where irregularities in the surface such as notches and/or projections are present.

The principle that is used for keeping light below a surface of the liquid which is present inside the space of the container, namely the principle of total internal reflection, is also used in the light guide. The lighting element is used for generating light at one end of the light guide, and the light that is introduced into the light guide travels for a considerable distance, which may be tens of centimeters, through the light guide, without noticeable losses. In the process, the light beams are continuously traveling from one side of the light guide to another under the influence of reflection, until the beams reach another end of the light guide and escape there. For the purpose of letting light escape from the light guide at specified places, a surface of the light guide is provided with irregularities at various positions, while the surface of the light guide is otherwise a substantially planar surface.

The light guide may be shaped like a pole, for example, and may be placed inside the space of the container so as to extend in a substantially vertical direction. In particular, it is possible for the light guide to extend through a portion of the wall of the container, for example, a portion which is at a bottom side in a normal orientation of the container, wherein a major portion of the light guide extends inside the space of the container, and wherein the lighting element is arranged at an end of the light guide which is outside the space of the container.

During use, light is introduced into the light guide, at one end of the light guide, and travels to another end on the basis of total internal reflection. In a portion of the light guide that is immersed in the liquid, at every position where irregularities are present in the surface of the light guide, the light is not reflected such as to stay inside the light guide, as is the case at other positions, but is allowed to escape from the light guide instead. This light is used to illuminate the liquid and to achieve a clearly visible difference between an illuminated area at the liquid side of the surface of the liquid and a non-illuminated area at the non-liquid side of this surface.

Light is not allowed to escape from a portion of the light guide which is above the surface of the liquid, assuming that this portion is surrounded by air, even at positions where irregularities are present in the surface of the light guide. This is caused by the fact that the refractive index of the liquid is higher than the refractive index of air, assuming that the liquid is water or another liquid which is commonly used in domestic appliances, while the material of the light guide may be chosen such that its refractive index is higher than the refractive index of the liquid. For example, the material of the light guide may be a plastic having a refractive index in the order of 1.5, whereas the liquid may be water, which has a refractive index of about 1.33. The refractive index of air is lower than these two values, namely 1.00. Light that remains inside the portion of the light guide which is surrounded by water, apparently includes a shallow angle with the surface of the light guide, and will surely not escape from the portion of the light guide which is surrounded by air, due to the fact that the difference in refractive indices is larger there.

The irregularities in the surface of the light guide may be arranged in any desired pattern. For example, the irregularities may be provided in the form of indentations which are positioned according to a regular pattern. According to another possibility, the surface of the light guide comprises roughened circumferential portions having a certain height, which are arranged at a certain mutual distance. In any case, the light guide may be very easy to manufacture, especially when the material of the light guide is chosen to be plastic, wherein the pattern of irregularities may simply be realized by applying moulding techniques. In fact, the entire wall of the container may be made out of one integral piece of plastic. In such a case, the light guide may be constituted by at least a portion of the wall of the container, so that there is no need for additional components, with the exception of the at least one lighting element. In general, within the scope of the present invention, the light guide may be an integral part of the container.

With respect to the portion of the wall of the container which is permeable to light, it is noted that it is preferred if this portion is semi-transparent and adapted to scatter light impacting on its inner surface in various directions. In this way, a better visual effect is obtained than in case the portion would be like window glass, for example.

The above-described and other aspects of the present invention will be apparent from and elucidated with reference to the following description of a number of embodiments of the container according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which: figure 1 shows a perspective view of a coffeemaker comprising a container according to the present invention, and serves to illustrate the fact that water which is present inside a space of the container seems to be emitting light; figure 2 diagrammatically shows a side view of a container which is equipped with a LED, and serves to illustrate the principle of total internal reflection; figure 3 diagrammatically shows a side view of a container which is equipped with an assembly of a LED and a float; figure 4 diagrammatically shows a bottom view of a portion of the container as shown in figure 3; figure 5 shows a perspective view of a light guide and LEDs; figures 6 and 7 diagrammatically show a side view and a top view, respectively, of a container which is equipped with a light guide; and figure 8 once again shows a side view of a container which is equipped with a light guide, and serves to illustrate the fact that light is only emitted from a portion of the light guide which is immersed in water which is present inside a space of the container.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a coffeemaker 1 comprising a container 2, which is also often referred to as water tank 2, and which serves for containing water to be used in the coffee-making process. In the case as shown, the water tank 2 is removably arranged with respect to a body 3 of the coffeemaker 1, so that a user may carry the water tank 2 to a tap or the like for filling the water tank 2. According to the present invention, the level of the water present inside a space 4 of the water tank 2 is clearly indicated, so that at any given moment, a user may easily judge whether filling is necessary, or may be postponed. To this end, a wall 5 of the water tank 2 comprises a semi-transparent material, which may be a plastic.

Furthermore, the water is illuminated in such a way that it seems to emit light itself, as may be seen in figure 1. As a result, a surface 6 of the water is clearly visible, as it is at the transition between water which seems to be brightly shining and a darker environment. In the following, the way in which this lighting effect is achieved will be explained, and various embodiments of the water tank 2 will be shown.

Figure 2 shows an embodiment of the water tank 2, in which the water tank 2 comprises a LED 10 which is arranged inside the space 4 of the water tank 2. When water is present inside the space 4 of the water tank 2, as shown in figure 2, the LED 10 is actually in the water. However, this is not an unsafe (?) situation, as the LED 10 is (?) an LED operating at a relatively low voltage, for example, a voltage of about 2.5 Volts. The LED 10 may be a colour LED 10 which is capable of emitting light in a limited range of directions. The LED

10 is arranged in the space 4 of the water tank 2 in such a way that the light beams propagate only sideward, i.e. horizontal and close to horizontal, so that the light beams 20 are parallel to the surface 6 of the water and close to parallel to this surface 6. It is noted that in figure 2 and other figures, light beams are depicted as arrows 20.

The light emitted by the LED 10 during its operation, in directions more or less parallel to the surface 6 of the water, cannot escape from the water, due to a phenomenon known as total internal reflection. The light beams 20 travel at angles with respect to the surface 6 of the water which are so small that the light beams 20 only reflect on this surface 6. In figure 2, the course of a number of light beams 20 is illustrated, and it can clearly be seen that the light beams 20 are reflected toward a portion of the wall 5 of the water tank 2 which is just below the surface 6 of the water, and escape from the water there. As a consequence, said portion of the wall 5 of the water tank 2 is brightly lit, so that there is a lot of light just below the surface 6 of the water, and hardly any light above this surface 6. Thus, the exact position of the surface 6 of the water may clearly be distinguished by a user.

Advantageously, the wall 5 of the water tank 2 comprises semi-transparent material, which may be a suitable plastic, so that the light impacting on the wall 5 is scattered in all directions, and the lighting effect is enhanced. When the LED 10 is arranged at a fixed position in the water tank 2, this position should be somewhat lower than a predetermined minimum level of the water in order to achieve the lighting effect for all possible levels of the water. However, in order to obtain the best possible lighting results, it is preferred that light is emitted just below the surface 6 of the water. Therefore, it is preferred to have means for adjusting the position of the LED 10 to the varying level of the water. In one possible embodiment, which is shown in figure 3, these means comprise a float 30, wherein the LED 10 is arranged at a bottom side of the float 30. In this way, as the float 30 is always at the level of the surface 6 of the water, it is ensured that the LED 10 is always close to this surface 6, while being in the water.

When the position of the LED 10 is adjustable, measures need to be taken for ensuring that a necessary power supply to the LED 10 can be maintained for all possible positions. According to one of many possibilities, which is illustrated by figures 3 and 4, rails

11 are applied for guiding the LED 10 up and down, wherein electrodes 12 are provided inside the rails 11 for contacting pickup areas of the LED 10 and transmitting power to the LED 10. As the electrical contacts are in the water, there may be a risk of rusting of these contacts; an alternative would be to simply connect wires (not shown) to the LED 10, which wires should be long enough to remain in contact with the LED 10 in all possible positions of the LED 10 in the water tank 20.

Another solution than applying a LED 10 which is arranged inside the space 4 of the water tank 2 is illustrated by figures 5-8, and comprises an application of a so-called light guide 40 and one or more LEDs 10 or other suitable lighting elements, wherein the LEDs 10 are arranged outside the space 4 of the water tank 2, and wherein at least a portion of the light guide 40 is arranged inside this space 4.

In a practical embodiment as shown in figure 5, the light guide 40 comprises a strip of transparent material such as a transparent plastic. In principle, many shapes of the light guide 40 are possible. In figures 6-8, a light guide 40 shaped like a pole is shown.

At one end 41 of the light guide 40, one or more LEDs 10 or other suitable lighting elements are arranged for generating light. The light beams 20 enter the light guide 40, and the phenomenon of total internal reflection takes place, as a result of which the light is kept inside the light guide 40. In particular, the light beams 20 are introduced into the light guide 40 at shallow angles with respect to a longitudinal axis of the light guide 40, i.e. with respect to a standing, cylindrically-shaped surface of the light guide 40, so that the light beams 20 only reflect on this surface and cannot escape from the light guide 40. In this way, it is achieved that the light travels from the end 41 of the light guide 40 where the LEDs 10 are arranged to another end 42, without noticeable losses.

In order to achieve that the light guide 40 emits light at predetermined positions, irregularities 43 are arranged in the surface of the light guide 40. In the example as shown in figure 5, these irregularities 43 are tiny scratches which are arranged such as to form a pattern of tiny dots. When a light beam 20 reaches a dot 43, it is capable of leaving the light guide 40, as the angle of impact on the surface of the light guide 40 at the position of the dot 43 is large enough to avoid total reflection. Hence, when the light guide 40 is illuminated by means of the LEDs 10, it seems that light is emitted by the dot 43. No electronics of any kind are present, apart from the LEDs 10 arranged at one end 41 of the light guide 40. As this end 41 may be arranged such as to be outside the space 4 of the water tank 2, into which the light guide 40 extends through the wall 5 of the water tank 2, it may be achieved that all the electronics are outside the space 4 of the water tank 2.

In the example of the light guide 40 as shown in figures 6-8, portions 43 of the surface of the light guide 40 are roughened. In particular, a rough structure 43 is applied at constant intervals along the length of the light guide 40 in such a way that ring-shaped roughened portions 43 having a certain height are obtained. Naturally, the intervals do not need to be constant; the only thing that matters is that there should be enough roughened portions 43 to have an emission of light which is always just below the surface 6 of the water, for all possible levels of the water. The roughened portions 43 have the same function as the dots 43 of the light guide 40 as shown in figure 5. Light may be extracted from the light guide 40 only at the positions of these portions 43. A factor which determines whether this will actually happen is the type of fluid surrounding the portions 43, as will be explained below.

The situation above the surface 6 of the water present in the space 4 of the water tank 2 differs substantially from that below the surface 6 of the water, due to the fact that above the surface 6, the light guide 40 is surrounded by air, and below the surface 6, the light guide 40 is surrounded by water. In particular, differences between the refractive index of the material of the light guide 40 on the one hand and the refractive index of the fluid surrounding it are different in both situations, and since these differences determine the angle at which light can escape from the light guide 40, it is clear that different lighting effects will be obtained above and below the surface 6 of the water, so that this surface 6 may be clearly visible to a user.

More specifically, the refractive index of common plastics is about 1.5. Furthermore, the refractive index of air is 1.00, while the refractive index of water is significantly larger, namely about 1.33. Consequently, the difference between the refractive indices of the plastic of the light guide 40 and the water is much smaller than the difference between refractive indices of the plastic of the light guide 40 and air, in other words, the difference between refractive indices below the surface 6 of the water is much smaller than the difference between refractive indices above the surface 6 of the water. In general, it is true that the larger the difference between the refractive index of the light guide 40 and its surroundings, the larger the angle of impact of light beams 20 on the surface of the light guide 40 has to be to enable an escape of the light from the light guide 40. At the end 41 of the light guide 40, which end is outside the space 4 of the water tank 2, the light is emitted by one or more LEDs 10, in directions which are parallel to and close to parallel to a longitudinal axis of the light guide 40, which extends in a substantially vertical direction in the shown examples. Light beams 20 impacting on a roughened portion 43 of the surface of the light guide 40 situated below the level of the water in the space 4 may escape from the light guide 40. Any light that remains inside the light guide 40 apparently has a shallow angle, so that it will certainly not escape from the light guide 40 at a location above the level of the water, as the difference between the refractive indices is larger there.

By making use of the natural principles as described in the foregoing, it is achieved that light that is emitted by one or more lighting elements 10 at one end 41 of a light guide 40 travels through this light guide 40, and is only allowed to escape at predetermined positions on a portion of the light guide 40 which is surrounded by water. Light entering the water will escape from the space 4 of the water tank 2 through the wall 5 of the water tank 2, which has translucent properties, but only at positions below the surface 6 of the water, as this surface 6 acts as a reflector for the light that reaches the surface 6 only at relatively shallow angles. All in all, by using a light guide 40 and one or more lighting elements 10 arranged at an end 41 of the light guide 40, the same lighting effect of the quantity of water present inside the space 4 of the water tank 2 is achieved as when one or more lighting elements 10 are arranged inside this space 4, whether or not attached to a float 30 or the like for following the level of the surface 6 of the water. Although the operation of the light guide 40 may seem complex, using a light guide 40 is a very attractive option for achieving the effect that looks as if a quantity of water is emitting light itself, as this only involves having a suitable piece of plastic arranged inside the space 4 of the water tank 2, and using one or more lighting elements 10 at one end 41 thereof. In fact, the water tank 2 including the light guide 40 may be manufactured of one integral piece of plastic, and the light guide 40 may even be an integral part of the wall 5 of the water tank 2.

Using one or more lighting elements 10 and/or a light guide 40 for indicating the water level hardly involves any additional costs, as no separate measurement system and indicator system are required. Furthermore, because it is achieved that the water present inside the space 4 of the water tank 2 seems to emit light itself, a very clear and accurate indicator is obtained.

It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the present invention as defined in the attached claims. While the present invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word "comprising" does not exclude other steps or elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the present invention. In the foregoing, a container 2 which is especially intended to be used in a domestic appliance such as a coffeemaker 1 comprises a space 4 for containing a liquid such as water, a wall 5 encompassing the space 4, and means for indicating the level of the liquid in the container 2 is disclosed. At least a portion of the wall 5 of the container 2 is permeable to light, and the liquid level indicating means comprise a light source 10, 40 which is adapted to emit light below a surface 6 of the liquid. In this way, a phenomenon known as total internal reflection may be used for illuminating the quantity of fluid present inside the space 4 of the container 2. Preferably, the light source 10, 40 is adapted to emit all the light at relatively shallow angles with respect to the surface 6 of the liquid, during its operation, in order to have an optimal total internal reflection process, wherein practically all the light is used for achieving the lighting effect as mentioned.

In one practical embodiment, the light source 10, 40 comprises one or more lighting elements 10 arranged inside the space 4 of the container 2. In another practical embodiment, the light source 10, 40 comprises a light guide 40 extending inside the space 4 of the container 2 or being an integral part of the wall 5 of the container 2, and one or more lighting elements 10 arranged at one end 41 of the light guide 40, wherein at various positions, a surface of the light guide 40 is irregular for the purpose of allowing light to escape at these positions.

By using liquid level indicating means as described, it is achieved that light is introduced into the liquid, and that this light reflects against a surface 6 of the liquid and only escapes in sideward directions, so that a clearly visible distinction between the surface 6 of the liquid and an adjacent medium (?) such as air is obtained. The level of the liquid is accurately indicated as the surface 6 of the liquid itself can be clearly seen.

Claims

CLAIMS:

1. Container (2) comprising a space (4) for containing a liquid, a wall (5) encompassing the space (4), and means for indicating the level of the liquid in the container (2), wherein at least a portion of the wall (5) of the container (2) is permeable to light, and wherein the liquid level indicating means comprise a light source (10, 40) which is adapted to emit light below possible levels of the surface (6) of the liquid in the container (2), in order to cause light emitted from below the surface (6) to reflect on the surface (6).

2. Container (2) according to claim 1, wherein the light source (10, 40) is adapted to emit light in directions which are horizontal and close to horizontal in a normal orientation of the container (2).

3. Container (2) according to claim 1, wherein the light source (10, 40) is adapted to emit light only in a limited range of directions, in particular in directions which are sideward in a normal orientation of the container (2).

4. Container (2) according to claim 1, wherein at least a portion of the light source (10, 40) is arranged inside the space (4) of the container (2).

5. Container (2) according to claim 1, wherein the light source (10, 40) is connected to a floating member (30), at a side of the floating member (30) which constitutes a bottom side in a normal orientation of the container (2).

6. Container (2) according to claim 1, wherein the light source (10, 40) comprises at least one light emitting diode (LED) (10).

7. Container (2) according to claim 1, wherein the light source (10, 40) comprises a light guide (40), i.e. a piece of material which is permeable to light, and at least one element (10) for generating light, wherein this lighting element (10) is arranged at an end (41) of the light guide (40), and this lighting element (10) is adapted to emit light to the interior of the light guide (40), at relatively shallow angles with respect to a surface of the light guide (40) in order to reflect on this surface, and wherein a surface of the light guide (40) is a substantially planar surface which is provided with irregularities (43) at various positions.

8. Container (2) according to claim 7, wherein the light guide (40) is shaped like a pole, and the light guide (40) extends through a portion of the wall (5) of the container (2), wherein a major portion of the light guide (40) extends inside the space (4) of the container (2), and wherein the lighting element (10) is arranged at an end (41) of the light guide (40) which is outside the space (4) of the container (2).

9. Container (2) according to claim 7, wherein the light guide (40) is constituted by at least a portion of the wall (5) of the container (2).

10. Container (2) according to claim 7, wherein the light guide (40) is an integral part of the container (2)

11. Container (2) according to claim 1, wherein the portion of the wall (5) of the container (2) which is permeable to light is semi-transparent and adapted to scatter light impacting on its inner surface in various directions.

12. Domestic appliance such as a coffeemaker (1), a water boiler or a steam iron, comprising a container (2) according to claim 1.