A SIMPLIFIED CONTROL PANEL FOR A BEVERAGE MACHINE

Abstract

A selection device (2) for a beverage preparation machine (1), comprises a fixed selection element (3) and a mobile selection element (4), the fixed selection element (3) comprising a set of marks (33) each corresponding to a parameter value, the mobile selection element (4) being movable in relation to the set of marks (33) for selecting a parameter value by positioning the mobile selection element (4) in visual association with a selected mark (33.sub.X). The selection device (2) further comprises a light-sending layer which is disposed in the fixed selection device (3), a polarization layer for polarizing said sent light, and at least one polarization modifying layer able to modify the polarization of the polarised light such that the visual aspect of a selected mark (33.sub.X) is modified when the mobile selection element (4) is positioned in visual association with the selected mark (33.sub.X), the polarization modifying layer being disposed in superposition relative to the polarization layer and relative to the selected mark (33.sub.X).

Claims

1. Selection device for a beverage preparation machine, comprising: a fixed selection element and a mobile selection element, the fixed selection element comprising a set of marks each corresponding to a beverage preparation parameter value, the mobile selection element being movable in relation to the set of marks for selecting a parameter value by positioning the mobile selection element in visual association with a selected mark, the selection device comprising a light-sending layer which is disposed in the fixed selection device, a polarization layer for polarizing the sent light, and at least one polarization modifying layer able to modify the polarization of the polarised light such that the visual aspect of a selected mark is modified when the mobile selection element is positioned in visual association with the selected mark, the polarization modifying layer being disposed in superposition relative to the polarization layer and relative to the selected mark.

2. Selection device according to claim 1, wherein the at least one polarization modifying layer able to modify the polarization of the polarised light comprises at least one wave-plate for shifting the phase between two perpendicular components of the polarised light, the visual aspect of the selected mark being modified or not as a function of the value of the phase shift.

3. Selection device according to claim 1, wherein the fixed selection element comprises a layer in which the set of marks is formed by making openings.

4. Selection device according to claim 3, wherein the layer in which the set of marks is formed is an opaque cap, each mark being represented by at least one opening.

5. Selection device according to claim 3, wherein the layer in which the set of marks is formed is the light-sending layer, the openings being filled and the rest of the layer being unfilled.

6. Selection device according to claim 1, wherein the fixed selection element comprises a rear part and a front part and the mobile selection element is configured to slide between the rear part and the front part, the light-sending layer being disposed in the rear part of the fixed selection element, the at least one polarization modifying layer being disposed in the fixed selection element and the polarization layer being disposed in the mobile selection element.

7. Selection device according to claim 1, wherein the fixed selection element comprises a rear part and a front part and the mobile selection element is configured to slide between the rear part and the front part, the light-sending layer being disposed in the rear part of the fixed selection element, the polarization layer being disposed in the front part of the fixed selection element, and the at least one polarization modifying layer being disposed in the mobile selection element.

8. Selection device according to claim 1, wherein it comprises comprising a second polarization modifying layer disposed in the fixed selection element and between the light-sending layer and the polarization layer.

9. Selection device according to claim 3, wherein the layer in which the set of marks is formed is said-the at least one polarization modifying layer, the at least one polarization modifying layer being disposed in the fixed selection element in superposition relative to the polarization layer and relative to the light sending layer.

10. Selection device according to claim 9, wherein each mark is represented by at least one opening made in the at least polarization modifying layer.

11. Selection device according to claim 9, comprising a second polarization modifying layer, the fixed selection element comprises a rear part and a front part and the mobile selection element is configured to slide between the rear part and the front part, the light-sending layer being disposed in the rear part of the fixed selection element, the polarization layer being disposed in the front part of the fixed selection element, and the second polarization modifying layer being disposed in the mobile selection element.

12. Selection device according to claim 1, wherein the light-sending layer comprises a reflective surface sending reflected light originating from the outside of the selection device and the at least one polarization modifying layer comprises one quarter-wave plate.

13. Selection device according to claim 1, wherein the light-sending layer comprises an illuminating surface, the selection device further comprising a second polarization layer disposed in contact with the light-sending layer, and the at least one polarization modifying layer comprises one half-wave plate.

14. Selection device according to claim 13, wherein the light-sending layer is illuminated by light originating from a light-emitting diode.

15. Beverage preparation machine comprising a selection device comprising: a fixed selection element and a mobile selection element, the fixed selection element comprising a set of marks each corresponding to a beverage preparation parameter value, the mobile selection element being movable in relation to the set of marks for selecting a parameter value by positioning the mobile selection element in visual association with a selected mark, the selection device comprising a light-sending layer which is disposed in the fixed selection device, a polarization layer for polarizing the sent light, and at least one polarization modifying layer able to modify the polarization of the polarised light such that the visual aspect of a selected mark is modified when the mobile selection element is positioned in visual association with the selected mark, the polarization modifying layer being disposed in superposition relative to the polarization layer and relative to the selected mark.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which:

[0047] FIG. 1 is illustrates a beverage preparation machine comprising a selection according to the invention;

[0048] FIG. 2 represents an exploded view of a selection device according to an embodiment of the invention;

[0049] FIGS. 3A and 3B represent respectively a section view and a top view of the selection device according to a first embodiment;

[0050] FIGS. 4A and 4B represent respectively a section view and a top view of the selection device according to a second embodiment;

[0051] FIGS. 5A and 5B represent respectively a section view and a top view of the selection device according to a third embodiment;

[0052] FIGS. 6A, 6B, 6C and 6D represents a plurality of top views of the selection device according to different embodiments; and

[0053] FIGS. 7A and 7B represent respectively a section view and a top view of the selection device according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0054] The invention is further described with reference to the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.

[0055] FIG. 1 illustrates a beverage preparation machine 1 according to one embodiment. The beverage preparation machine 1 comprises a selection device 2 allowing a user of the machine to select a value for a parameter used in the preparation of the beverage.

[0056] By way of a non-limiting example, the user may select the fluid volume for the beverage.

[0057] Naturally, the parameter value which may be selected by a user by means of the selecting device may be different, for example a fluid temperature, a pressure or infusion time.

[0058] As it will be further described in reference to FIG. 2, the selection device 2 comprises a fixed selection device 3 and a mobile selection device 4.

[0059] The fixed selection device 3 comprises a set of marks 33 each corresponding to a parameter value. The mobile selection device 4 is movable in relation to the set of marks 33 for selecting a parameter value by positioning the mobile selection element 4 in visual association with a selected mark (no mark is selected in FIG. 1).

[0060] In the embodiment represented in FIG. 1, the mobile selection device 4 comprises an elongated piece. According to an example, in order to select a volume value, the user positions the elongated piece 4 in superposition relative to a mark corresponding to the wished volume value.

[0061] It should be noted that FIG. 1 represents an example of beverage preparation machine 1 and of a selection device 2.

[0062] Naturally, the beverage preparation machine 1, and in particular the selection device 2 may presents different forms.

[0063] FIG. 2 shows an exploded view of the selection device according to an embodiment.

[0064] As indicated above, the selection device 2 comprises a fixed selection element 3 and a mobile selection element 4. The fixed selection element 3 comprises a rear part 31 and a front part 32 and the mobile selection element 4 is configured to slide between the rear part 31 and the front part 32.

[0065] The fixed selection element 2 comprises a set of marks 33 each corresponding to a parameter value. The set of marks is disposed in the front part 32 of the fixed selection element 2 such that it can be viewed by a user of the beverage machine.

[0066] The set of marks 33 comprises a plurality of marks which are referred in the Figures as 33.sub.X, X being the number of marks. According to a non-limitative example, the marks 33.sub.X are aligned (vertically in FIG. 1) and each mark 33.sub.X presents a rectangular shape each rectangular shape being of a different length, the length gradually increasing from a first mark 33.sub.1 to a last mark 33.sub.7 (X being equal to 7 in this embodiment). In the embodiment described hereafter in reference to the drawing, the series of marks on the surface of the control panel of the machine, are arranged and dimensioned so that the whole set of marks represents schematically the shape of a cup.

[0067] Naturally, the number, the shape and the arrangement of the marks may be different. For example, the marks may be of circular, square, oblong or other shape, and the marks may be aligned vertically or horizontally or form together a figure such as for example a circle. Also, the marks 33.sub.X may be of similar or different size.

[0068] The mobile selection element 4 is movable in relation to the set of marks 33 for selecting a parameter value by positioning the mobile selection element 4 in visual association with a selected mark.

[0069] The mobile selection element 4 is in visual association with a selected mark 33.sub.X, for example when the mobile selection element 33 is situated in superposition relative to the selected mark or close to the selected mark.

[0070] According to one embodiment which is represented in FIG. 2, the mobile selection element 4 comprises an extremity part 41 and a panel 42. The extremity part 41 comprises an elongated piece.

[0071] In this example, a mark 33.sub.X is considered as selected when the elongated piece is positioned in superposition relative to the mark 33.sub.X. Thus, when the elongated piece is superposed relative to the selected mark 33.sub.X, the mobile selection element 4 is in visual association with the selected mark 33.sub.X.

[0072] As a variant, an extremity part 41 may be situated close to the selection mark without being disposed in superposition. This extremity part 41 may be a piece, presenting any form, which is positioned close to a selected mark 33.sub.X.

[0073] Naturally, the form of the panel 42 may be different from the represented form.

[0074] For example, the form of the panel may be planar or curved, depending on the form of the fixed selection element 3.

[0075] According to another embodiment, the mobile selection element 4 comprises only a panel 42 which slides between the rear part 31 and the front part 32 of the fixed selection device 3. A mark 33.sub.X is considered as selected when the panel 42 is positioned in superposition relative to the mark 33.sub.X, the end of the panel being close to the mark 33.sub.X (as for example in FIGS. 3, 4 and 5).

[0076] According to another embodiment, the mobile selection element 4 comprises only an extremity part 41 (as for example in FIGS. 6A, 6B and 6D). The extremity part 41 comprises for example an elongated piece designed to be positioned in superposition relative to a selected mark 33.sub.X.

[0077] A section view of a part of the selection device 2 according to an embodiment is shown by FIG. 3A. FIG. 3B represents schematically a corresponding top view.

[0078] The selection device 2 comprises a light-sending layer 21 for sending light, a polarization layer 22 for polarising the light passing through it, for example the light sent by the light-sending layer 21, and a first polarization modifying layer 23a able to modify the polarization of the polarised light such that the visual aspect of a selected mark is modified when the mobile selection element 4 is positioned in visual association with the selected mark 33.sub.X.

[0079] In the embodiment represented by FIGS. 3A and 3B, the light-sending layer 21 is disposed in the rear part 31 of the fixed selection element 3, the polarization layer 22 is disposed in the front part 32 of the fixed selection element 3, and the first polarization modifying layer 23a is disposed in the mobile selection element 4.

[0080] The fixed selection element 3 comprises a layer in which said set of marks 33 is formed by making openings.

[0081] According to the embodiment represented by FIGS. 3A and 3B, the layer 24 in which the set of marks 33 is formed is an opaque cap 24, each mark 33.sub.X being represented by at least one opening 240.sub.X.

[0082] Thus, as shown in FIGS. 3A and 3B, a first mark 33.sub.1 is formed by a first opening 240.sub.1 implemented in the opaque cap 24, a second mark 33.sub.2 is formed by a second opening 240.sub.2 and a third mark 33.sub.3 is formed by a third opening implemented in the opaque cap 24.

[0083] In the described example, the fixed selection element 3 comprises a second modifying layer 23b disposed between said light-sending layer 21 and said polarization layer 22.

[0084] According to one embodiment, the first and second polarization modifying layers 23a, 23b able to modify the polarization of the polarised light comprises one wave-plate for shifting the phase between two perpendicular components of the polarised light, the visual aspect of the selected mark being modified or not as a function of the value of said phase shift.

[0085] It should be noted that depending on the type of wave-plate the value of phase shift is different. For example, if the wave-plate used is a quarter-wave plate, a first component of polarised light is delayed with respect to a second component by 90°. According to another example, if the wave-plate used is a half-wave wave plate, a first component of polarised light is delayed with respect to a second component by 180°.

[0086] In this example embodiment, the optical axis of the wave-plate and the optical axis of the polarization layer are off-set (or shifted) one relative to the other by an angle of 45°.

[0087] In this example a first mark 33.sub.1 is selected by a user of the beverage machine. Thus, the mobile selection element 4 slides such that it is situated in superposition relative to the first opening 240.sub.1, an inner end 40 of the mobile selection element 4 being situated between the first 240.sub.1 and a second 240.sub.2 opening.

[0088] As represented by FIGS. 3A and 3B, the first polarization modifying layer 23a and de second polarization modifying layer 23b are disposed in superposition relative to the polarization layer 22 and relative to the selected mark 33.sub.1.

[0089] In the described example, the light-sending layer 21 comprises a reflective surface sending reflected light originating from the outside of the selection device. Therefore, in this example, a light wave 10a originating from the outside of the selection device and that goes into the selecting device 2 through the first opening 240.sub.1, passes successively through the polarization layer 22, the first wave-plate 23a, and the second wave-plate 23b and finally arrives at the light -sending layer 21(here the reflective surface).

[0090] Thus, a delayed polarised light wave 10b is reflected by the reflective surface 21 and passes successively through the second wave-plate 23b, the first wave-plate 23a and the polarization layer 22, and finally goes out from the selection device 2 by the first opening 240.sub.1.

[0091] As a consequence, the first opening 240.sub.1, i.e. the first mark 33.sub.1, appears illuminated, and thus, in contrast with the rest of the opaque cap 24, the opaque cap 24 preventing the light from entering the selecting device 2.

[0092] Concerning the second opening, a light wave 11a that goes into the selecting device 2 through the second opening 240.sub.2, passes successively through the polarization layer 22, and the first wave-plate 23a and finally arrives at the light-sending layer 21 (here the reflective surface).

[0093] Thus, a delayed polarised light wave 11b is reflected by the reflective surface 21 and passes successively through the second wave-plate 23b and the polarization layer 22. In this case, a delayed light wave 11c cannot go out through the second opening 240.sub.2, and the second opening 240.sub.2, i.e. the second mark 33.sub.2 appears obscured or not illuminated.

[0094] It should be noted that by virtue of the polarization of the light entering and leaving the selection device 2, the difference between the visual appearance of an illuminated zone and of a non-illuminated zone is accentuated.

[0095] Naturally, the position of the first polarization layer 23a and the second polarization layer 23b may be different in the selection device.

[0096] For example, the second polarization modifying layer 23b may be positioned at the front part of the fixed selection element, in contact with the polarization layer 22, the mobile selection element 4 sliding between the second polarization modifying layer 23b and the light-sending layer 21.

[0097] In other embodiments, the opaque cap 24 may be positioned at different positions between the light-sending layer 21 and the polarization layer 22.

[0098] FIGS. 4A and 4B represent schematically a section view and a top view of a selection device 2 according to another embodiment.

[0099] According to this embodiment, a light-sending layer 21′ is disposed in the rear part 31 of the fixed selection element 3, a polarization layer 22′ is disposed in the front part 32 of the fixed selection element 3, and a first polarization modifying layer 23a′ is disposed here in the rear part 31 of the fixed selection element 3.

[0100] The selection device 2 comprises a second polarization modifying layer 23b′ disposed in the mobile selection device 4.

[0101] In this embodiment, the light-sending device 21′ comprises a reflective surface and the polarization modifying layers 23a′, 23b′ comprises each one wave-plate.

[0102] According to an example, each of the wave-plates is a quarter-wave plate.

[0103] According to the described embodiment, the layer in which the set of marks 33 is formed is the first polarization modifying layer 23a′.

[0104] The first polarization modifying layer 23a′ comprises a wave-plate in which the set of marks 33 is formed by making openings 240.sub.1′, 240.sub.2′, 240.sub.3′. Thus, each opening 240.sub.1′, 240.sub.2′, 240.sub.3′ represents a mark 33.sub.1′, 33.sub.2′, 33.sub.3′ each corresponding to a parameter value.

[0105] In this example a first mark 33.sub.1′ is selected by a user of the beverage machine 1. Thus, the mobile selection element 4 is configured to slide such that it is situated in superposition relative to the first opening 240.sub.1′ and the inner end 40 of the mobile selection element 4 is situated between the first 240.sub.1′ and a second 240.sub.2′ opening.

[0106] In this example, at the first mark 33.sub.1′, a light wave 10a′ originating from the outside of the selection device, passes successively through the polarization layer 22′, and the second polarization modifying layer 23b′ or second wave-plate, goes through the first opening 240.sub.1′, and finally arrives at the light-sending layer 21′ (here a reflective surface).

[0107] Thus, in this example, the light wave 10a′ passes through only one wave-plate 23b′, the polarised light wave being delayed by 90°.

[0108] The delayed polarised light wave 10b′ is reflected by the reflective surface 21′ and passes through the second wave-plate 23b. The reflected light wave 10c′ is thus delayed by 90°, the light wave 10a′ being delayed in total by 180°.

[0109] Therefore, the 180° delayed light wave 10d′ cannot go out from the selecting device 2, and the first mark 33.sub.1′ appears obscured or not illuminated.

[0110] A light wave 11′a in the selection device around the mark 33.sub.1′ passes successively through the polarization layer 22′, the second wave-plate 23b′ and the first wave-plate 23a′, and finally arrives at the light-sending layer 21′.

[0111] Thus, the light wave 11a′ is delayed by 180° and the delayed polarised light wave 11b′ is reflected.

[0112] This reflected light wave 11c′ passes successively through the first wave-plate 23a′, the second wave-plate 23b′, and the polarization layer 22′ and finally goes out from the selection device 2′. Thus, the zone of the selection device 2 around the first mark 33.sub.1′ is illuminated.

[0113] It should be noted that the light wave 11a′ is delayed in total by 360°.

[0114] Therefore, the contrast between the first mark 33.sub.1′ and the zone of the selection device around the first mark 33.sub.1′ is incremented, rendering clearer the view of the selected mark.

[0115] A light wave 12a′ passing through the polarization layer 22′ at the level of a non-selected mark, for example the third mark 33.sub.3′, is reflected by the light-sending layer 21′. The reflected light wave 12c′ passes through the polarization layer 22′ and goes out from the selection device 2. Thus the third opening 33.sub.3′ (and the second one 33.sub.2′) is illuminated.

[0116] It should be noted a polarised light wave at a non-selected mark does not passes through any wave-plate, the light wave not being delayed.

[0117] In the selection device 2 where the first wave-plate 23a′ is not disposed in superposition relative to the first wave-plate 23a′ (corresponding to the selection device 2 around a non-selected mark such as 33.sub.2′ and 33.sub.3′ in FIGS. 4A and 4B), light passes through the first wave-plate 23a′ twice and it appears obscured or not illuminated.

[0118] Naturally, as described in reference to FIGS. 3A and 3B, the position of the first and second polarization modifying layers may be different.

[0119] FIGS. 5A and 5B represent schematically a section view and a top view of a selection device 2″ according to another embodiment.

[0120] According to this embodiment, a light-sending layer 21″ is disposed in the rear part 31 of the fixed selection element 3, a polarization layer 22″ is disposed in the front part 32 of the fixed selection element 3, and a first polarization modifying layer 23a″ is disposed in the mobile selection element 4.

[0121] The fixed selection element 3 comprises a second polarization modifying layer 23b″ disposed in superposition relative to the light-sending layer 21″ and relative to the polarization layer 22″.

[0122] In this embodiment, the polarization modifying layers 23a″, 23b″ comprises each one wave plate.

[0123] According to an example, each of the wave-plates is a quarter-wave plate.

[0124] According to this embodiment, the layer in which the set of marks 33″ is formed is the light-sending layer 21″ the openings being filled and the rest of the layer being unfilled.

[0125] In this embodiment the light-sending layer 21″ comprises zones that are filled with a reflective surface (zones corresponding to openings) and zones which are unfilled or not filled with a reflective surface.

[0126] A light wave 10a″ passing through the polarization layer 22″, at the level of a selected mark 33.sub.1″, passes successively through the first wave-plate 23a″ and the second wave-plate 23b″, and finally arrives to the light-sending layer 21″. The light-sending layer 21″ comprising a reflective surface at the level of the mark 33.sub.1″ or opening 240.sub.1″, the delayed light wave 10b″ is reflected and passes successively through the second wave-plate 23b″, the first wave-plate 23a″ and the polarization layer 22′, and finally goes out from the selecting device 2″.

[0127] Thus, selected mark 33.sub.1″ appears illuminated. The rest of the selecting device appears obscured or not illuminated.

[0128] It should be noted that in this embodiment, the zones of the selection device 2 corresponding to the marks 33″ which are not selected appears less obscured than zones of the selecting device not corresponding to a mark 33″. Even if a slight quantity of light is reflected by the reflecting layer, this slight quantity of reflected light is not polarised and the appearance of the mark is obscure.

[0129] Naturally, as described in reference to FIGS. 3A and 3B, the position of the first and second polarization modifying layers may be different.

[0130] According to embodiments represented by FIGS. 3, 4 and 5, the mobile selection device 4 comprises only a panel 42 that slide between the rear part 31 and the front part 32 of the fixed selection device 3.

[0131] The mobile selection device may comprise an extremity part 41 as explained above.

[0132] According to the embodiment represented by FIGS. 3, 4 and 5, marks preceding a selected mark 33.sub.X, 33.sub.X′, 33.sub.X″ appears illuminated if the selected mark appears illuminated and not illuminated if the selected mark appears not illuminated.

[0133] Thus, for example if the third mark 33.sub.3, 33.sub.3″ is the selected mark and it appears illuminated (as in FIGS. 3 and 5), the first mark 33.sub.1, 33.sub.1″ and the second mark 33.sub.2, 33.sub.2″ appear also illuminated.

[0134] According to other embodiments, the polarization layer 22, 22′, 22″ and the polarization modifying layers 23a, 23b, 23a′, 23b′, 23a″, 23b″ may be situated differently.

[0135] For example, according to an embodiment (not represented), the polarization layer is disposed in the mobile selection element 4, in particular in an extremity part 41 which is configured to be positioned in superposition of a selected mark.

[0136] Thus, for example, according to this not represented embodiment, the selection device 2 comprises a light-sending layer and a polarization modifying layer situated in the rear part 31 of the fixed selection element 3 and an opaque cap situated in the front part 32 of the fixed selection element 3. The openings corresponding to the marks are formed in the opaque cap. The mobile selection element 4 comprises an elongated piece (as that one represented in FIG. 2 and referenced 41). The polarization layer is situated in the elongated piece.

[0137] When the elongated piece is positioned in superposition to a mark, light is polarized and enters the selection device 2 through the opening corresponding to the selected mark.

[0138] According to the explanations above, if the selection device 2 comprises only a quarter-wave-plate, the selected mark appears obscured. If two quarter-wave-plates are positioned in superposition, the mark appears illuminated.

[0139] It may be noted that depending on the number of quarter-wave-plates that are positioned in superposition, the selected mark appears illuminated or not illuminated.

[0140] A top view of a selection device 2 according to this embodiment is represented by FIG. 6A. In this embodiment, the mobile selection element 4 comprises only an extremity part 41 formed by elongated piece.

[0141] According to an example, the extremity part 41 is positioned in superposition of a third mark 33.sub.3′″, the selected mark 33.sub.3′″ appearing obscured.

[0142] It should be noted that in the described embodiment, the mark 33.sub.3′″ appears obscure if the selection device comprises an odd number of quarter-wave plates. On the contrary, the mark appears illuminated if the selection device comprises an even number of quarter-wave plates.

[0143] In general, according to a same structure of selection device, if light passes through an odd number of polarization modifying layers rendering a mark illuminated, when light passes through an even number of polarization modifying layers, a mark appears obscured, and vice-versa.

[0144] Naturally, as described above, the shape of the marks may be different.

[0145] According to an example represented by FIG. 6B, a mark may be represented by a plurality of symbols. In FIG. 6B each mark is formed by a rectangle and succession of points inside the rectangle. The aspect of the points and the rectangle are inversed and the aspect of both is different for a selected mark and for a non-selected mark.

[0146] FIG. 6C represents an embodiment in which the set of marks is invisible when no mark is selected.

[0147] This embodiment may be achieved for example by a selection device comprising, as the example represented by FIG. 4A, a light-sending layer (a reflective surface), a first polarization modifying layer disposed in superposition of the light-sending layer and a polarization layer, all being disposed in the fixed selection element 3.

[0148] In an example, the set of marks is formed in the polarization modifying layer by making openings.

[0149] In this embodiment, the first polarization modifying layer comprises a quarter-wave plate, the optical axis of the wave-plate and the optical axis of the polarization layer forming an angle of 0° or 90°.

[0150] The mobile selection element 4 comprises a second modifying layer which comprises a second quarter-wave plate, the optical axis of the second wave-plate forming an angle of 45° with the optical axis of the polarization layer.

[0151] In this embodiment, when no mark is selected, the surface of selection device 2 viewed by a user appears illuminated. When the mobile selection element 4 slides into the fixed selection element 3, an obscured or non-illuminated mark appears when the mobile selection element 4 is positioned in superposition relative to the mark (selected mark).

[0152] Naturally, a similar result may be obtained with other structures, for example with a structure as represented in FIG. 7A in which the light-sending layer comprises an illuminating surface, and the optical axis of polarization modifying layer (reference 230a) forms an angle of 0° or 90° with the optical axis of the first polarization layer (reference 220a).

[0153] According to another embodiment, the selection device may comprise a structure of layers similar to that represented in FIG. 3A, in which the axis of the second polarization modifying layer (reference 23b) forms an angle of 0° or 90° with the optical axis of the polarization layer (reference 22). In this embodiment, when no mark is selected, the surface of the selection device viewed by a user appears obscured or non-illuminated.

[0154] When the mobile selection element slides into the fixed selection element, a mark appears illuminated when the mobile selection element is positioned in superposition relative to the mark (a selected mark).

[0155] Naturally, in other embodiments, the light-sending layer may comprise an illuminating layer.

[0156] As represented by FIG. 6D, if the mobile selection element 4 comprises only an extremity part 41 formed by an elongated piece configured to be positioned only in superposition relative to the selected mark (such as the mobile selection device represented by FIGS. 6A and 7B), only the selected mark appears obscured.

[0157] According to other embodiments, the polarization modifying layers 23a, 23b (or at least one of them) may be situated in the front part 32 of the fixed selection element 3 such as the light originating from the outside of the machine is polarized.

[0158] In such an embodiment, a polarization layer is also situated in the front part 32 of the fixed selection element 3.

[0159] FIGS. 7A and 7B represent schematically a section view and a top view of a selection device 200 according to another embodiment.

[0160] In this embodiment, the selection device 200 comprises a first polarization layer 220a, a second polarization layer 220b, a first polarization modifying layer 230a, a second polarization modifying layer 230b and a light-sending layer 210.

[0161] In this embodiment, the fixed selection element 300 comprises the light-sending layer 210 comprising an illuminating surface.

[0162] It should be noted that the term “light-sending” means sending light, either directly from a light source or indirectly by reflecting light.

[0163] Thus, in embodiments where a light-sending layer comprises a reflective surface, light-sending by the light-sending layer comprises reflection at the reflective surface, i.e. the light-sending layer sends light by reflecting light at the reflective surface.

[0164] In embodiments where the light-sending layer comprises an illuminating surface, the light-sending layer sends light originating from the illuminating surface, i.e. from a light source illuminating the illuminating surface.

[0165] The fixed selection element 300 comprises further the first polarization layer 220a disposed in the front part 31 of the fixed selection device 3, the second polarization layer 220b disposed in contact with the light sending layer and the first polarization modifying layer 230a.

[0166] Naturally, the number of polarization modifying layer may be higher and depending on the wished appearance of the selection device 2.

[0167] The mobile selection element 400 comprises the second polarization modifying layer 230b.

[0168] In this embodiment, the polarization modifying layers 230a, 230b comprises each one half-wave plate. A half-wave plate delays a polarized light wave by 180°.

[0169] In this example, the set of marks 330 is formed by making openings in the first half-wave plate 230a (the one situated in the fixed selection element).

[0170] Naturally, in other examples, the set of marks 330 may be formed in the light-sending layer or in an opaque cap as described above for other embodiments, and as described in reference to FIGS. 3A and 3B, the position of the first and second polarization modifying layers may be different.

[0171] In this embodiment, the first polarization layer 220a polarizes light originating of the light-sending layer 210, this polarized light passes through one or two half-wave plates (depending on the situation of the mobile selection element 4), and respectively do not goes from or goes from the selecting device 200.

[0172] In FIG. 7B, the first mark 330.sub.1 is selected by positioning the mobile selection device 400 in superposition relative to the selected mark 330.sub.1. Light entering the selection device 200 through the first opening that corresponds to the selected mark 330.sub.1, passes through only one half-wave plate, the selected mark appearing obscured.

[0173] On the contrary, the selection device 200 appears illuminated around the selected mark 330.sub.1.

[0174] The non-selected marks 330.sub.2, 330.sub.3 appear illuminated and the zones of the selection device 200 around the non-selected marks appear obscured. It may be noted that the visual result is equivalent to the one according to the embodiment described in reference to FIG. 4.

[0175] The viewing of a selected mark is highly improved with this embodiment. In particular, the viewing of a selected mark is independent of the luminosity around the selection device.

[0176] According to an embodiment, the light-sending layer 210 is illuminated by light originating from a light-emitting diode.

[0177] For example, the light-sending layer comprises a flexible light-emitting diode such as an Organic Light-Emitting Diode.

[0178] Light sent by the light-sending layer may be of different colors that can be chosen according to aesthetical concerns.

[0179] According to another embodiment, the light-sending layer 210 is illuminated by light originating from an optical fiber.

[0180] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims.