The invention relates to a shaver comprising adjustment means, for adjusting a particular shaving feature through movement (i.e. rotation or linear motion) of said adjustment means, and feedback means for providing a user with feedback regarding the adjustment of the shaving feature. Such shavers are commercially available, for instance in applicant's Sensotec product line.

This known shaver comprises a shaving head provided with a series of cutters which are adjustably mounted in the shaving head by means of a support structure that biases the cutter to an outward position. During operation, a contact pressure is needed to press the cutters inward, into a position wherein they lie about flush with the shaving head. This contact pressure is a measure for the shaving sensitivity and can be adjusted by displacing the support structure with help of adjustment means, such as a thumb wheel. Signs are printed on the adjustment means and the housing to provide the user feedback regarding the amount and direction of the adjustment needed or already accomplished. A disadvantage of these known feedback means is that the signs are usually rather small owing to limited available space on and near the adjustment means. Moreover, the signs may become easily contaminated during use, thereby seriously affecting their feedback performance. It has already been proposed in WO application with filing no. IB2004/050132 to provide the adjustment means with a click-arrangement that generates a clicking sound during operation of the adjustment means. Although this acoustic feedback functions properly, there exists a need for alternative feedback means, for instance in situations wherein audibility is poor, e.g. due to considerable background noise (possibly generated by the shaver itself) or a hearing disability of the user.

It is therefore an object of the invention to provide a shaver having adjustment means of the type described above with feedback means that can provide a user with clear and detailed information on the adjustment of a particular shaving feature. To that end a shaver according to the invention is characterized by the features of claim 1. Thanks to the conversion arrangement, any movement of the adjustment means can be converted into an electrical signal representative of said movement and consequently of the accomplished adjustment. This electrical signal can be readily and clearly presented to a user, for instance graphically or numerically on a screen or by means of other visible indicators, such as a LED, audible indicators, such as sound-generating means, or tactile indicators, such as vibrating means, empowered by said electrical signal. Thus, by converting the mechanical movement of the adjustment means into an electric signal, a large number of ways becomes available in which the adjustment information can be fed back to the user, thereby enabling for every situation a suitable, clear presentation tailored to a user's needs or personal preferences. In further elaboration, a conversion arrangement according to the invention is configured according to the features of claim 2. In this configuration, one or more electrically conductive contact members are in direct sliding contact with a conversion element having conductive and non-conductive zones. The contact member or conversion element is coupled to the adjustment means such that any movement of these adjustment means causes a relative movement between the contact member and the conversion element. During this movement, the contact member alternately passes a conductive zone and a non-conductive zone, thereby acting as a switch which alternately closes and opens an electric circuit. The resulting electrical signal will have an on/off pattern which provides information on the position of the adjustment means. Thanks to the direct sliding contact between the contact member and the conductive and non-conductive zones, the space-consuming mechanical switches and activating means normally used for converting a mechanical movement into an electrical signal can be dispensed with, resulting in a compact arrangement. Such an arrangement is particularly (but not exclusively) suitable for use in equipment with limited available space, such as the shaver described above or, for example, a mobile phone, a power tool, a palmtop, or a portable audio/video device. Moreover, with a configuration according to claim 2, electric wiring can be minimized, since the sliding contact members can be directly connected to the inputs of a micro-controller, and the conductive zones can be easily interconnected for connection to one common contact, resulting in a robust, reliable conversion arrangement. The conductive and non-conductive zones are preferably spaced such that the resulting combination of closed and opened switches produces an electrical signal of multibit codes. Thus the movement of the adjustment means is directly converted into a digital signal, without the need for further digital conversion means, which adds to the simplicity of the design and saves space and costs. In a preferred embodiment having the features of claim 4, the conductive members are fixedly mounted in the shaver, whereas the conversion element is mounted to be moved by the adjustment means. The stationary contact members can be directly connected to the inputs of a (stationary) micro-controller in that case, which reduces the amount of wiring needed, and as such renders the arrangement more simple and robust, as was explained above. The conversion element can be fixedly connected to the adjustment means (preferably even be integrally formed therewith, as will be discussed below) or be configured as a separate part to be moved by the adjustment means via suitable transmission means. The latter option offers the advantage that similar conversion elements can be used with different adjustment means, e.g. a rotary wheel, or a linear slide, by simply adapting the transmission means (e.g. a toothed wheel, a rack). Of course it is also possible to have the contact members move with the adjustment means and let the conversion element remain stationary. In either case, the conversion element is preferably designed and positioned such that at least the more vulnerable parts of the arrangement, Le. the conductive zones and conductive members, are situated in a 'clean' part of the shaver, shielded against external contamination, such as hair stubs, skin particles, shaving gel, or the like, which may enter the shaver during operation. A conversion arrangement according to the present embodiment furthermore offers the advantage that its geometry can be easily adapted to a given situation, by simply altering the shape of the conversion element and/or the orientation of the conductive zones and contact paths with respect to the contact members, as claimed in any one of claims 5 to 8. In this way the conversion arrangement according to the invention can be easily adapted to fit a particular movement of the adjustment means (e.g. a rotary or linear movement) or to fit within the available space, making the arrangement even more widely applicable. An advantageous embodiment of a shaver according to the invention is characterized by the features of claim 9. Making the conductive parts of the conversion arrangement of a non-insulating material means that little energy will be drawn from a main power supply of the shaver during operation of the arrangement, thus leaving the performance of the shaver substantially unaffected. In a highly preferred embodiment, the conversion element is manufactured according to the features of claim 10. Making both the conductive and non-conductive zones of the conversion element of a suitable conductive and non-conductive plastic, respectively, the element can be manufactured by 2-K injection molding, wherein said conductive and non-conductive zones are molded in two separate, consecutive steps. 2-K injection molding is fast and economical and allows for complex designs. The invention furthermore relates to an adjustment assembly according to the features of claim 11. Such an assembly can advantageously be used in a shaver according to the present invention, but may alternatively be applied in other electronic equipment or household appliances with mechanical adjustment means and feedback means, especially equipment or appliances in which the available space for said means is limited. Further advantageous embodiments of a shaver having adjustment means and a conversion arrangement according to the invention are set forth in the dependent claims.

To explain the invention, exemplary embodiments thereof will be described below with reference to the accompanying drawings, wherein: Fig. 1 shows a device, in particular a shaver according to the invention, provided with an adjustment assembly according to the invention, for adjusting the shaving sensitivity; Fig. 2 shows in perspective view the adjustment assembly of the device of Fig. 1 in more detail, seen from below; Figs. 3A-D show four successive states of the conversion arrangement, corresponding to four different positions of the adjustment means; Fig. 4 shows the conversion element of Figs. 3A-D, at least the conductive portion thereof, suitable for being manufactured in a first step of a 2-K molding process; Fig. 5 shows an alternative embodiment of the conversion arrangement, wherein the conductive and non-conductive zones are arranged in concentric circles at an axial end of the conversion element, and the contact members are arranged in axial abutment with said conversion element; and Fig. 6 shows an alternative embodiment of the conversion arrangement, wherein the conductive and non-conductive zones are arranged in linear, substantially parallel paths for use with linear moving adjustment means, such as e.g. a slider.

In the following description, the invention will be explained in its application in a shaver. It is emphasized, however, that the application of the adjustment and feedback means according to the invention is not limited to shavers, but is equally possible in other devices with mechanically adjustable features, notably (but not exclusively) electronic equipment or household appliances with limited available space, such as mobile phones, portable audio/video equipment, palmtops, irons, or the like. The shaver 1 illustrated in Fig. 1 comprises a housing 2 and a shaving head 3 hinged or otherwise detachably connected to said housing 2 and provided with cutters 4, three in the given embodiment. These cutters 4 are resiliently suspended in the shaving head 3 by means of a support structure (not shown), comprising an adjustable support and a resilient pressure member that biases the cutters 4 into an outward position wherein they protrude from the shaving head 3. Consequently, a certain contact pressure is needed to press the cutters 4 into a more inward position. During use, this contact pressure is exerted by a user's skin and determines the shaving sensitivity. The higher the contact pressure, the greater the shaving depth. The necessary contact pressure can be adjusted by altering the position of the adjustable support. To that end, the shaver 1 is provided with an adjustment structure 5, which is shown in more detail in Fig. 2. This adjustment structure 5 comprises adjustment means in the form of a dial gear or thumb wheel 6, which is mounted with rotation possibility about a first rotation axis 12, in a base 13 of the shaver housing 2 to which the shaving head 3 is connected. The thumb wheel 6 is located near an edge of this base 13, such that a circumferential edge portion of the wheel 6 is accessible from outside the housing 2 for operation, for instance by a user's thumb or otherwise. The thumb wheel 6 is provided with a central shaft 7 which, during operation of the wheel 6, is rotated together therewith and extends into a compartment of the shaver 1 which is shielded off against external contamination, the advantage whereof will become apparent below. A first gear wheel 8 is mounted somewhere halfway the shaft 7 and engages a second gear wheel 9 via an intermediate third gear wheel 11. The second gear wheel 9 is rotatably mounted about a second rotation axis 17, at a central position of the shaver 1. Rotation of this gear wheel 9 causes the adjustable support to be moved up or down a threaded guide (not shown), depending on the direction of rotation of thumb wheel 6. It will be clear to the skilled person that the adjustment structure may be configured differently, depending among other aspects on the feature to be adjusted. For instance, in the abovementioned embodiment of Fig. 2, the third gear wheel 11 may be omitted so that the first gear wheel 8 directly engages the second gear wheel 9. Alternatively, the third gear wheel 11 may be replaced by a plurality of third gear wheels 11, e.g. to obtain a desired transmission ratio between the first and second gear wheels 8, 9. Furthermore, bevel gear wheels may be applied to allow the rotation axes 12, 17 of the thumb wheel 6 and second gear wheel 9 to enclose an angle. To provide a user with feedback on the adjustment, the shaver 1 furthermore comprises feedback means 10 comprising a conversion arrangement 15 for converting the rotation of the thumb wheel 6 into a representative electrical signal, and presentation means 14 for presenting the feedback signal to the user. In the illustrated embodiment, the presentation means 14 comprise a screen. It will be clear that other or additional presentation means may be used, for instance LEDs, sound-generating means, or the like, for providing the user with audible, visible, and/or tactile feedback. The conversion arrangement 15 includes a conversion element, formed by the free end of shaft 7, and a set of electrically conductive sliding contact members 16, in the present case three members 16A-C. These contact members 16A-C tangentially abut the shaft 7 by their first, curved ends 18 and are connected to the inputs of a (micro-)controller (not shown) by their other ends 19. The shaft 7 is provided with contact rings 20A-C, which in number and positions equal the number and positions of the contact members 16A-C, so that during rotation of the shaft 7, each of the contact members 16A-C contacts the shaft 7 along a dedicated ring 20A-C. The rings 20A-C are electrically insulated from each other in axial direction by rings of non-conductive material 23. As can be best seen in Fig. 3, the first ring 2OA, i.e. the one closest to the first gear wheel 8, is fully made of conductive material, and as such constitutes one conductive zone 21. The neighboring second ring 2OB is divided into two annular segments, one made of conductive material so as to form a conductive zone 21, the other made of non-conductive material thereby constituting a non-conductive zone 22. The third and last ring 2OC is divided in four annular segments, i.e. two conductive zones 21, alternated by two non-conductive zones 22. The conductive zones 21 of the three contact rings 20A,B,C are mutually electrically connected and connected to a common contact via the first contact member 16A. The other two contact members 16B and 16C are each connected to an individual terminal (not shown) and each form, together with the respective second or third contact ring 20B,C, a switch which is closed when the contact member 16B5C passes a conductive zone 21 and opened when it passes a non-conductive zone 22. In operation, when the thumb wheel 6 is rotated by a user to adjust the shaving sensitivity via first, second, and third gear wheels 8, 9 11 as explained above, the shaft 7 will be rotated as well. Consequently, the contact members 16A-C will slide along the respective contact rings 20A-C, thereby closing and opening said switches, resulting in four different binary switch combinations per revolution (i.e. both switches open, both switches closed, one switch open the other one closed, and vice versa), as illustrated in Figs. 3A-D, corresponding to four positions of the adjustment means 6. It will be clear that, if space allows, the conversion arrangement 15 may be provided with more contact members 16 and corresponding contact rings 20, which will generate more binary switch combinations, resulting in an increased measurement sensitivity. Alternatively, the number of switch combinations may be increased by connecting the conversion element to a common contact, so that the first contact ring 2OA, which in the illustrated embodiments is dedicated as a common contact of the arrangement, becomes available to be divided into conductive and non-conductive zones. Furthermore, the orientation of the contact members 16 with respect to the conversion element 7 and contact paths 20 may be varied, for example, to optimally fit in the available space. Fig. 5 shows for instance an embodiment in which the conversion element 107 is disc-shaped, having contact paths 120 extending in concentric circles at one side of the disc, the contact members 116 lying in axial abutment with said paths 120. Operation and working principle are similar to those of the embodiment illustrated in Figs. 2-4. Of course, the conversion arrangement 15, especially the shape and/or orientation of the conversion element 7 and the contact members 16 may be configured in many alternative ways, depending among other aspects on the available space and the characteristics of the adjustment structure 5. For example, the adjustment means may comprise a linear slider (not shown) instead of the rotatable thumb wheel 6, to be moved along a side of the triangular shaving head 3. This linear movement can be converted into a rotating movement of the second gear wheel 9 by means of, for example, a toothed rack coupled to the slider and engaging the second or an intermediate gear wheel 9, 11. The conversion arrangement 15 could then be coupled to the second gear wheel 9 and have a similar configuration as the embodiment of Figs. 2-4, or be coupled to the slider, in which case the conversion element 207 may be redesigned as illustrated in Fig. 6, featuring a substantially rectangular plate provided at one surface with linear contact paths 220A-C, separated by linear non-conductive paths 223, which all extend substantially parallel in the direction of movement of the slider (indicated by arrows A, B). The first contact path 220A consists of one conductive zone 221, which may serve as common contact for the arrangement. The other two contact paths (220B,C) are divided into one conductive zone and two conductive zones 221, respectively, alternating with non-conductive zones 222, as illustrated. The contact members 216A-C are arranged to contact the conversion element 207 along the linear paths 220A-C, thereby generating a digital electrical signal when passing the alternating zones 221, 222, as described above. Of course, the number of contact paths 220 and corresponding contact members 216 may be reduced or increased in accordance with the desired measurement sensitivity. For all embodiments, the non-conductive zones, rings, and/or paths 22, 122, 222; 23, 123, 223 maybe made, for example, of plastic, and the conductive zones 21, 121, 221 may be made from conductive plastic, metal, or plastic plated with metal (e.g. chromium, copper, gold, silver, nickel). Preferably, the conversion element 7, 107, 207 is manufactured by 2-K injection molding, wherein the conductive zones 21, 121, 221 of the conversion element 7, 107, 207 are injection molded in a first step as one integral part, as illustrated in Fig. 4, and wherein the missing non-conductive zones, rings, and paths 22, 122, 222; 23, 123, 223 are injection molded in a subsequent second step, during which the mold is opened and one mold half is replaced with a suitable other mold half. Of course, the order in which the parts are molded can be reversed, i.e. first the non-conductive zones 22, 122, 222; 23, 123, 223 and subsequently the conductive zones 21, 121, 221. 2-K injection molding offers the advantage that it is fast and economical and requires no handling of the intermediate product, which remains in the stationary mold half during replacement of the other mold half. Moreover, complex shapes can be manufactured with 2-K injection molding, allowing freedom of design. In a further preferred embodiment, the conversion element 7, 107, 207 is integrally molded with the adjustment means 6, so that the number of separate parts and consequently the assembling cost can be reduced. Furthermore, the conversion element 7, 107, 207 is preferably designed such that at least the contact paths 20, 120, 220 and contact members 16, 116, 216 extend in a sealed-off portion of the shaver 1, as illustrated in the embodiment of Fig. 2. In that way, these relatively vulnerable parts (contact members and contact paths) are well protected against external shocks and contamination. The invention is not in any way limited to the exemplary embodiments shown in the description and the Figures. Many variations thereof are possible within the scope of the invention as outlined by the claims. The conversion element may be configured, for example, as a hollow tube provided with contact paths at its inner wall and revolving around contact members centrally positioned within the tube. Alternatively, the tube may be stationary while the contact members rotate. Such a configuration could offer the advantage that the relatively vulnerable contact members are well protected by the conversion element. These and many comparable variations are understood to fall within the scope of the invention as outlined by the claims.