DK2851167T3

DK2851167T3 - Hair clipping device with integrated light source and integrated light guide

Info

Publication number: DK2851167T3
Application number: DK13004637.8T
Authority: DK
Inventors: Peter Scheunert; Bernd Schmitt
Original assignee: Exonda Salon Tools Gmbh
Priority date: 2013-09-24
Filing date: 2013-09-24
Publication date: 2018-10-22
Also published as: EP2851167B1; ES2693681T3; EP2851167A1

Description

The present invention relates to a hair-cutting device having a housing extending in a longitudinal direction, a cutter head with a cutting device, said cutting device being aligned in a main direction of extension, a light source arranged in the interior of the housing, and a light guide having an input area and an output area respectively for light from the light source and set up to pass the light from the input area to the output area and direct it onto the cutter head, said light guide being arranged in the interior of the housing such that said output area is arrangeable in optical communication with the cutting device .

Hair-cutting devices, such as for example electric razors, in particular dry shavers of any desired design, or indeed hair removal appliances in general, are used in the most varied situations. In the morning under poor light conditions or for elderly people with poor eyesight it is important to be able to control the position of the haircutting device relative to the face or the skin in a simple manner. Dampening of the area to be shaved, for example on the human head, is very helpful in this respect. However, even in the case of use by barbers or any desired other second party, a light source on the hair-cutting device is very useful, since it makes possible simpler control of the working result, and since it also simplifies positioning and guidance of the hair-cutting device relative to the relevant part of a person's body.

Hair-cutting devices with a light source are known, for example from the following prior art publications. EP 1 657 485 Bl discloses a hair-cutting device with a cutter head and with a light source arranged behind a lens forming part of a housing of the hair-cutting device, wherein an area to the side of the cutter head is illuminated. EP 1 326 739 Bl discloses a hair-cutting device with a cutter with a blade in the shape of a semi-annulus, a light source and a light guide, wherein the light guide is of semicircular cross-section and is arranged within the blades. The light guide may be integrated into the cutter and thereby arranged directly against the working surface. US 2013/0042481 Al discloses a hair-cutting device with a cutter and a light source, which latter is arranged in a separate housing on the outside of the housing of the haircutting device and is able to shine externally laterally along the housing of the hair-cutting device. DE 29 33 922 Al discloses a hair-cutting device with a cutter head and a light source arranged in a housing of the hair-cutting device, which light source is able to shine light onto a shaving location to the side of the cutter head via a lens or in conjunction with a reflector and a light guide. DE 21 22 379 A discloses a hair-cutting device with a cutter and a light source, which latter is arranged in a housing of the hair-cutting device and is set up to illuminate a cutting surface, wherein a reflector is provided inside the housing for reflecting light onto the cutting surface.

According to WO 2007/044461 Al, light guides extend in the interior of the hair-cutting device, said light guides having LEDs arranged at their proximal ends and their distal ends being aligned with a cutting blade via orifices .

In a shaving appliance according to DE 2 117 663 A, light is focused onto a point in front of an area to be shaved via optical fibre bundles.

The subject matter of DE 23 44 437 A is a shaving appliance with an incandescent lamp, which is arranged in a cap extending from the shaving appliance housing and having a light-transmitting dome for illuminating a region spaced relative to the cutting edges.

In a razor according to US 2 635 179 A, lighting is provided inside the housing from which light is passed via conductors so as to be able to illuminate areas of the skin .

The object of the present invention is to provide an improved hair-cutting device with integrated light source, in particular a hair-cutting device which simplifies working with the hair-cutting device.

The above-stated object is achieved by a hair-cutting device according to claim 1, namely a hair-cutting device having a housing extending in a longitudinal direction; a cutter head with a cutting device, preferably with at least one motor-driven cutter, said cutting device, in particular the cutter, being aligned in a main direction of extension, i.e. also aligned in the main direction of extension at least to a significant extent; a light source arranged in the interior of the housing; and a light guide having an input area and an output area respectively for light from the light source and set up to pass the light in particular in the longitudinal direction from the input area to the output area and direct it onto the cutter head; said light guide being arranged in the interior of the housing such that said output area is arrangeable or disposable in optical communication with the cutting device. Furthermore, the output area has a convexity such that at least a certain proportion of the light is focusable onto the cutting device. Provision is furthermore made for at least a certain proportion of the light to be alignable in the cutting direction. Light source and light guide are here preferably fully integrated into the housing.

The output area is here preferably arranged spacedly, in particular spacedly relative to the longitudinal direction, from the cutting device, such that at least a proportion of the light which exits from the output area may be scattered more widely and a wider area than the output area may be illuminated.

The invention is here based on the idea of directing or casting light from a geometrically small light source, in particular a punctiform light source, in a definable direction of extension onto a cutting device by means of a light guide, in particular mainly distributing it in just one main direction, specifically also in the case of linear cutting devices or cutting devices extending at least in one main direction, i.e. for example in the case of linear cutters. This may be achieved by arranging the light guide in the housing and guiding it out of the housing at a position in which the light guide may be in optical communication with the entire cutting device, in particular all the parts or portions of a cutter of the cutting device. The main direction of extension is preferably at least approximately orthogonal to the longitudinal direction .

Such a light guide is set up to illuminate a working area of the cutter head, in particular the cutting device, substantially fully and at the same time to be arranged compactly inside the housing, in particular spacedly from the cutter head.

An arrangement in optical communication should here be understood to mean an arrangement in which the output area is in visual contact with the cutting device and the light guide is aligned such that light from the light guide, in particular from a distal end of the light guide, may be cast onto the cutting device. The light may be directed directly from the output area onto the cutting device, in particular from a definable distance. Further reflectors or lenses or other optical devices are not needed, and can preferably be omitted. If desired, however, such components could be provided in the beam path.

The light guide is preferably arranged between the light source and a front, distal end (pointing towards the cutting device) of the housing, and bridges the distance between the light source and the distal end of the housing. In this case, one possible arrangement of the light source is on a printed circuit board in the middle of the housing, in particular at an appropriate proximity to a storage battery or any circuit, and the distance may be used to adapt the cross-section through which light flows between the light source and the cutting device geometrically in the direction of light propagation to an ever greater degree, in particular continuously, to the cutting device.

The cross-section, in particular the cross-section through which light flows, of the light guide preferably has a geometry which is selected from the group comprising circular, elliptical, plate-like or rectangular with rounded corners. Cross-sections with a continuously extending peripheral line without edges or projections may preferably be selected. According to one variant, the cross-section through which light flows of the light guide is circular in the input area and rectangular in the output area. These cross-sections may for example be selected when the light is to be input in punctiform manner and output in linear manner over the width of the cutter head.

The light guide is preferably guided out of the housing at a distal end of the housing, in particular a distal edge of the housing. The light guide is preferably arranged wholly in the interior of the housing apart from the output area. In this case, the light guide may form part of the housing at the distal end of said housing, in particular by the light guide being arranged such that one surface of the light guide merges continuously with an outer circumferential surface of the housing.

The light guide is preferably set up to pass light on from the light source within the light guide by total reflection. The light guide may to this end have reflection surfaces which extend at an angle to one another or to the input area which is greater than a critical angle for total reflection. In this way, the light may be passed on efficiently. The critical angle is here dependent on the wavelength of the light and the material used. The light source is preferably one or more LED(s). This enables a weight-optimised embodiment and a long service life or indeed long storage battery life due to low power consumption .

The cutting device is preferably arranged at a distal end of the hair-cutting device. The cutting device is preferably designed as a cutter head with two cutting elements moving relative to one another, wherein one of the cutting elements or both cutting elements may be mounted so as to be movable. According to one variant, the cutting device extends substantially transversely of the longitudinal direction, wherein the light guide may be designed at least at the distal end as an edge or rim which likewise predominantly extends transversely of the longitudinal direction.

The light guide is preferably not arranged in direct connection with any component of the cutter, but rather spaced therefrom. This makes it possible to expand still further light from an output area which is preferably smaller or less wide than the cutting device. The output area does not in this case have to be as large dimensionally as the cutting device. The output area is preferably arranged spaced from the cutter head. The spacing amounts to for example 1 to 30 mm, preferably 3 to 20 mm, more preferably 5 to 15 mm. A spacing of at least 3 to 5 mm is appropriate for illuminating the cutting device uniformly and over the entire width. If the spacing is markedly greater than the stated range, the light exit may possibly be covered up/shaded by a gripping hand or a tool used (for example a comb). It is further preferred for the output area to be arranged between the housing, in particular a housing top, and the cutting device, in particular at a specific (preferably uniform) spacing from the cutting device. The spacing makes it possible to mount the light guide on the housing wholly independently of a cutter head and to achieve illumination also independently of the cutter head. A cutter may be replaced without affecting the illumination function. In this way, a barber may also operate the hair-cutting machine with different cutters or cutter heads or attachments.

According to one embodiment, the light guide is set up to orient the light selectively onto the cutting device, in particular in the main direction of extension along the cutting device. Selective orientation or illumination should here be understood to mean illumination where the output area is set up or arranged in such a way that the light is mainly cast onto the cutting device, wherein the cutting device is illuminated as fully as possible. Selective lighting/illumination has the advantage that (optionally) substantially only the cutting device is illuminated, and not any surrounding appliance parts or surfaces of a person. In this respect, even a linear cutting device may be lit up by means of an individual, in particular punctiform light source. The distance between light source and cutting device may be used to expand or fan out the cross-section through which light flows of the light guide. The output area may be oriented in such a way relative to the cutting device that the light may be directed along the main direction of extension onto the cutting device. The output area is preferably arranged along the cutting device, for example at least in places at least approximately parallel to a cutter of the cutting device. The output area preferably extends at least in places along the cutting device.

Selective orientation of the light may be assured in that the input area has a geometry which corresponds to the geometry of one or more light sources, wherein the output area has a geometry which corresponds to the geometry of the cutting device.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide has a cross-section through which light flows which is adapted geometrically in the output area to the geometry of the cutting device. In this way, a light cone exiting in the output area may be adapted geometrically to the geometry of the cutting device, and (if desired) selective illumination of (solely) the cutting device may be assured, i.e. without any surrounding areas. A possible adaptation should here be understood to be a geometric configuration of the output area in which the output area has, for example in the main direction of extension or orthogonally thereto, a geometry comparable to the geometry of the cutting device, in particular of an individual cutter, wherein a size factor may also be at play. The size factor may be selected as a function of a defined spacing between the output area and the cutting device. Illumination solely of the cutting device and preferably not (or at most only to a small degree) of any surrounding areas or parts of the skin provides the advantage that light may be concentrated even more on the working location, or that a good illumination effect of the relevant areas may be achieved with little luminous power. The geometry of the output area may, in particular in the case of strong, punctiform light sources, such as LEDs, also attenuate the light intensity, such that there is no risk to a user even if said user looks directly at the output area. From the input area to the output area, the cross-section through which light flows may be approximated geometrically to the geometry of the cutting device, in particular it may diverge in each case towards one end of the cutting device.

The light guide may have a cross-section through which light flows which diverges from the input area to the output area. A diverging cross-section should here be understood to mean a cross-section which expands at least in one of the two spatial directions of the cross-sectional plane. The light guide may be set up to expand, in particular fan out, the light in the main direction of extension. In this way, even a cutting device extending in linear manner may be substantially fully illuminated. The light guide may in this case expand geometrically from the input area to the output area, in particular in the form of a trumpet or a funnel or a hyperbola.

Viewed in the longitudinal direction x (direction of light guidance), the output area may preferably be of convex design, in particular at least approximately circular arcshaped. In other words, the output area is arched or curved around a z axis. The output area then has a curvature relative to a YZ plane. In this way, a light cone exiting in the output area may be fanned out, such that the widest possible segment may be lit up.

The light guide may in this case be designed as a flat, in particular fan-shaped body. The light guide may be designed as a body extending at least approximately in planar manner in the main direction of extension. The light guide may be plate-shaped, in particular it may be designed as a light guide plate.

In this case, the light guide extends in the main direction of extension and is set up to expand the light within the light guide from the input area as far as the output area relative to the main direction of extension. The light may be fanned out in the light guide in the main direction of extension between opposing reflection surfaces of the light guide, in particular in the case of total reflection at least at the reflection surfaces.

In other words, the light guide may have an extent in a direction other than the longitudinal direction, in particular a transverse direction transversely of the longitudinal direction, which is greater than an extent in a further, third spatial direction. In this way, light from a light source, in particular an at least approximately punctiform light source (preferably LED), may be expanded in the main direction of extension and directed in the shape of a fan onto the cutting device. In this case, a single light source may illuminate a cutting device which is significantly wider than the size of the light source.

The reflection surfaces are in each case either planar and/or curved, and may be arranged at least approximately in parallel, at least in places. The reflection surfaces may in each case have individual surface sections arranged adjacent one another in the longitudinal direction which may be arranged at an angle to one another. In this way, light guidance, in particular by total reflection, within the light guide may be optimised in conjunction with a light guide geometry which is adapted to the geometry of the housing.

The reflection surfaces preferably extend in a plane which is defined by the main direction of extension and the longitudinal direction, at least to a significant degree or with individual surface portions. The reflection surfaces extend at least approximately in the main direction of extension, in particular with an angle deviation of less than 20, preferably less than 10, more preferably less than 5 degrees. According to one variant, the reflection surfaces do not extend exactly in this plane, but rather at a small angle to this plane, for example an angle of between 0 and 10 or at most 15 degrees. In this way, for example the light may be expanded along a circular arc arranged in an XY plane.

The reflection surfaces may have a width in the main direction of extension in the region of a distal end of the light guide which amounts to at least 20 per cent, preferably at least 35 per cent, more preferably at least 50 per cent of the width of the cutting device in the main direction of extension. The width may amount to 20 to 100 per cent, preferably 30 to 80 per cent, more preferably 40 to 60 per cent of the width of the cutting device.

According to one variant, the width is approximately 50 per cent. With these size ratios, the entire or at least a major part of the cutting device may be illuminated, without the light having to be scattered too strongly in the output area; excessive scattering would make selective illumination of the cutting device more difficult. In other words, in the case of planar reflection surfaces extending preferably at least approximately in parallel, the crosssection through which light flows may be as wide as possible relative to the width of the cutting device in the output area.

The reflection surfaces may be reflection surfaces arranged opposite and spaced from one another. The distance between the reflection surfaces preferably decreases towards the distal end of the housing, i.e. they draw closer to one another. In this way, on the one hand an arcuate or linear or fan-shaped output area may be formed, on the other hand the light guide may be integrated in the housing in a practical manner. In particular, the output area may form a light edge or a light rim, which forms a housing edge. The output area need not necessarily be arcuate, it may also extend in at least approximately linear manner in one spatial direction, in particular in a straight line.

The light guide is preferably arranged adjacent an inner surface inside the housing, in particular an inner surface of a housing top. One of the reflection surfaces is preferably guided along an inner surface of the housing.

The light guide preferably extends from the light source to the distal end of the housing along the inner surface of a housing top. The light guide may be arranged in the housing in such a way that at least one of the reflection surfaces is directed towards a cutter of the cutting device, and in particular is oriented at least approximately in the longitudinal direction.

According to one embodiment, which may be combined with any one of the above-described embodiments, a distal end of the light guide, in particular the output area of the light guide, lies against a distal end of the housing. In this way, the light guide may be integrated into the housing in such a way that the light may be output at an advantageous location. In addition, the housing may also be simply sealed in this way.

The distal end preferably forms the distal end of the housing, at least in places. The output area preferably forms a light edge at the distal end of the housing. It is also preferable for the output area to form a distal edge of the housing at least in places. A distal end, in particular the output area, of the light guide is preferably fan-shaped. According to one variant, the light guide is cross-sectionally linear, in particular arcuate, in particular in the output area. In this case, the cross-sectional geometry may for example develop continuously from a more circular cross-section in the input area into a rectangular, elongate cross-section in the output area.

In the output area, the light guide preferably has a contact surface against which the housing comes to rest.

The contact surface forms a recess, in particular on one of the reflection surfaces, which has a height in a direction orthogonal to the longitudinal direction relative to the corresponding reflection surface. The light guide may thereby be caused to rest flush against the housing.

According to one embodiment, which may be combined with any one of the previously described embodiments, the light guide has a top located outside the housing, in particular in the output area, which has a geometry which is coordinated with the geometry of the housing. The light guide may thereby be integrated into the housing and form a part of the housing. With this arrangement, the output area may be brought simply into optical communication with the cutting device. It may also in this respect be made readily visible to a user whether the light source is in operation.

The top, when viewed from inside the housing (or from the bottom of the light guide) is preferably convex with outward curvature, in particular according to a corresponding curvature of the housing.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide has a convexity in the output area, in particular a convex outer edge, at which the light is scatterable or may be scattered, in particular in an XZ plane perpendicular to the main direction of extension. In this way, at least a certain proportion of the light may also be focused, in particular onto the cutting device. A type of light rim may be formed, which is also easily visible for an operator, even when looking sideways at the housing. At least a certain proportion of the light may moreover also be directed in front of the cutting device, provided the latter provides advantages for a given hair-cutting device or a given type of application. At the convexity, the light may also be oriented at least to a certain degree in the cutting direction, i.e. in front of the cutting device or in front of the cutter head when viewed in the working direction .

The convexity is preferably formed at least in part by a radius between a top and a front side of the light guide. The radius may be dimensioned in accordance with the size of the output area and/or the thickness of the light source. If a particularly prominent light edge or a particularly conspicuous light rim is to be provided, the radius is on the small side. The radius may here point towards the cutting device and also assume a focusing function for the light guided in the light guide.

According to one embodiment, which may be combined with any one of the above-described embodiments, the output area has a front side which is arranged at a definable angle relative to the longitudinal direction, in particular at an angle of 20 to 70 degrees, preferably 30 to 60 degrees, more preferably 40 to 50 degrees, in particular 45 degrees. In this way, the light guide may be arranged compactly in the housing, in particular directly below an inner surface of a housing outer part, and at the same time also be aligned relative to the cutting device, especially in the case of cutting devices which are arranged obliquely in a plane relative to the housing or to the longitudinal direction. The front side is preferably arranged in a plane which is at least approximately parallel to a plane in which the cutting device is arranged. In this way, the light may be cast onto the cutting device over a large angle, in particular over at least approximately a right angle, so as effectively to avoid forming or casting long shadows, in particular shading by hair or other small parts .

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide is arranged inside the housing such that sealing of the input and/or output areas from the environment is assured. The input and/or output area may be adapted geometrically to the housing in such a way, in particular with contours corresponding to the contour of the housing, that hair or dirt particles cannot reach the light source or enter the housing. The light guide may provide soiling protection, in particular soiling protection for the light source and/or the entire housing interior. The light guide may assume a function as housing element, in particular by arranging the output area in such a way that the interior of the housing is delimited from the surrounding environment by means of the output area. In the case of an output area which corresponds geometrically with the housing, the light guide may itself be a housing element.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide is in contact in the output area with a holder of the cutter head. This results in stable support for the light guide and optionally also sealing of the housing.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide is geometrically adapted in the output area both to the housing and to the cutter head. In other words, the light guide corresponds geometrically in the output area both to the geometry of the housing and to the geometry of the cutter head. In this way, the light guide may ensure sealing both between the housing and the cutter head.

According to one embodiment, which may be combined with any one of the above-described embodiments, the input area has a concave, inward-curving geometry. This makes it possible to use a small, in particular punctiform light source, for example an LED, and to input the beams of light efficiently without major losses. The input area may be shaped geometrically in such a way that the light emitted in punctiform manner impinges in the input area at least approximately orthogonally on the light guide and enters the light guide.

The input area preferably takes the shape of a segment of a sphere or at least approximately of a segment of a sphere. The input area may in this case also be formed only by a relatively small segment of a sphere, i.e. by a segment of a sphere with a relatively large radius. In other words, the input area may be flat with a large curvature radius. The light source may be positioned in a cavity which is formed between the input area and a printed circuit board or another fastening means, for example a housing part. The light source may be arranged in the cavity adjacent the input area. In this case, the light source may also have a convex outer circumferential surface (which may be provided for example by an additional lens), which corresponds for example with the concave geometry of the input area. The input area may also have a shape other than that of a segment of a sphere, for example in order to orient the beams of light at least approximately in parallel in the direction of the light guide.

According to one embodiment, which may be combined with any one of the above-described embodiments, the input area may have a width in the main direction of extension which is smaller than a width of the output area in the main direction of extension, in particular smaller by a significant factor, wherein the factor amounts for example to between 1/2 and 1/20, preferably 1/3 and 1/15, more preferably 1/4 and 1/10, in particular between 1/5 and 1/7. This makes it possible to use an individual or a plurality of individual inexpensive spot emitters such as LEDs. In this case, the cross-section through which light flows of the light guide may be widened in the illumination direction, not least because of the extension of the light guide in the longitudinal direction. The factor is preferably greater, the wider is the cutter head. Haircutting machines may have a cutter head width of around 50 mm, contour trimmers in particular having a cutting head width of around 30 mm, and special-purpose machines, for example for shaved hair tattoos, a cutting head width of only around 5 mm.

According to one embodiment, which may be combined with one of the above-described embodiments, the light guide comprises a proximal end, which is wider than the input area and/or which projects over or overlaps the input area in the proximal direction (i.e. contrary to the direction of light propagation). In this way, the light guide may on the one hand be fastened simply in the housing, in particular by means of fastening means arranged directly at the proximal end. On the other hand, the input area or a light source arranged adjacent the input area may be sealed, in particular from hair or comparably small parts.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light guide has in the input area a surface section which is aligned with said input area such that light can be passed on to it by total reflection. In this way, light output loss can be minimised, in particular in conjunction with a projection which overlaps the input area in the proximal direction. The surface section is preferably arranged in a plane which extends between the input area and the projection.

According to one embodiment, which may be combined with any one of the above-described embodiments, the light source is arranged on a fastening element connected to the housing, in particular on a printed circuit board, the light guide having a projection which overlaps or grips around said fastening element, in particular engages beneath the fastening element on the side of the fastening element facing away from the housing. In this way, on the one hand the input area may be sealed, while on the other hand the light source may be protected, in particular from hair. The fastening element is preferably connected with an inner surface of the housing, in particular of the housing top.

According to one embodiment, which may be combined with one of the above-described embodiments, the housing has a bulge designed for at least partially receiving the light guide. The light guide may be arranged or accommodated at least in part in the bulge. In this way, the light guide may be simply integrated into existing hair-cutting device designs. Retrofitting is also possible, simply by retrofitting the light source and light guide and changing the corresponding housing part. The bulge additionally makes it possible to arrange the output area in direct optical communication with the cutting device.

Nevertheless, the light guide may also be integrated into a housing without a bulge (in particular an externally visible bulge). The bulge has the advantage, however, that other components of the hair-cutting device do not have to be displaced to provide space for the light guide.

The invention is explained in greater detail on the basis of exemplary embodiments shown in the figures below, in which:

Fig. 1 is a sectional view along a central longitudinal axis of a hair-cutting device according to one exemplary embodiment of the invention;

Fig. 2 is a plan view of a detail of a light guide of the hair-cutting device shown in Fig. 1;

Fig. 3a is a side view of the light guide shown in Fig. 2 in the direction of a proximal end of the light gu i de;

Fig. 3b is a side view of the light guide shown in Fig. 2 in the direction of a distal end of the light gu i de;

Fig. 3c is a sectional view of the light guide shown in Fig. 2 along section A-A;

Fig. 4 is a sectional view along a central longitudinal axis of a hair-cutting device according to one exemplary embodiment of the invention;

Fig. 4b is a side view of the hair-cutting device shown in Fig. 4a;

Fig. 4b is a plan view of the hair-cutting device shown in Fig. 4a;

Fig. 5a is a detail view in section of detail B shown in

Fig. 4a; and

Fig. 5b is a detail view in section of detail C shown in Fig. 4a.

Fig. 1 shows a hair-cutting device 1 with a housing 10 with a housing top 11 and a housing bottom 12. The housing 10 may optionally also be of one-piece design. The housing top 11 extends substantially along the entire hair-cutting device 1 as far as a cutter head 40 of the hair-cutting device 1 and ends in a distal end 11a spaced from the cutter head 40. The cutter head 40 comprises a cutting device 41 and extends in a main direction of extension Y.

In a front, distal area of the housing 10, a light guide 20 is arranged which has a distal end 20a and a proximal end 20b. The distal end 20a is arranged at the distal end 11a of the housing top 11. The geometry of the distal end 20a of the light guide 20 corresponds with the geometry of the distal end 11a of the housing top 11. A printed circuit board (a fastening element for a light source) 30 is additionally arranged in the housing top 11, in particular on a partition 13 fastened to the housing top 11, wherein the partition 13 extends at least approximately orthogonally to an inner surface 11.1 of the housing top 11. A light source 31, in particular an LED, is fastened to the printed circuit board 30, wherein the light source 31 is only indicated schematically. The geometry of the light source 31 in this case does not necessarily correspond to the geometry of the proximal end 20b of the light guide 20.

The light source 31 may be arranged in cavity formed between the proximal end 20b and the printed circuit board 30. The proximal end 20b of the light guide 20 is arranged adjacent the light source 31.

The light guide 20 has an upper reflection surface 21 and a lower reflection surface 22. The reflection surfaces 21, 22 extend along the inner surface 11.1 of the housing top 11. The reflection surfaces 21, 22 have a mutually comparable orientation in the longitudinal direction x (direction of light guidance). The reflection surfaces 21, 22 may extend at least approximately parallel in the longitudinal direction x (direction of light guidance) over a distance. In the longitudinal direction x (direction of light guidance), the thickness or height (in terms of the z direction) of the light guide 20 decreases, i.e. the light guide 20 becomes shallower in the longitudinal direction. At the distal end 20a, the light guide 20 has an output area at which a contact surface of the distal end 11a of the housing top 11 comes to rest against a corresponding contact surface of the light guide 20. The output area fits snugly against the distal end 11a of the housing top 11. Light L exits at the output area and is directed substantially onto the cutting device 41 (fat arrow L), but also to a certain extent (when viewed in the working direction) in front of the cutting device 41 (dashed arrows L) .

Fig. 2 shows the light guide 20 in detail. The output area 24 extends in linear manner. The output area 24 has an arcuate geometry. The output area 24 of the light guide 20 forms a part of the free distal end 20a of the light guide 20. At the proximal end 20b of the light guide 20, an input area 23 is arranged into which light from a light source (not shown) may be input. The light guide 20 has a projection 25 which projects over or overlaps the input area 23 in the proximal direction. The input area 23 may be formed by a milled recess at the proximal end 20b, wherein the milled recess may also form the projection 25. At the proximal end 20b, the light guide 20 has fastening means 28, indicated here in the form of a bore in a lug. The light guide 20 may be fastened to the housing top 11 relative to all three spatial directions using the bore 28, in particular by means of a screw. The light guide 20 has a right-hand lateral surface 27a and a left-hand lateral surface 27b, and the right-hand lateral surface 27a is subdivided into in a first surface section 27a.1 and a second surface section 27a.2. The left-hand lateral surface 27b likewise has a first surface section 27b.1 and a second surface section 27b.2, wherein the surface sections are arranged separately from one another. Depending on the arrangement of the input area 23, the surface sections may also merge together, such as in the case of the right-hand lateral surface 27a. The two first surface sections 27a.1, 27b.1 widen in the longitudinal direction x (direction of light guidance) in such a way that the width increases in the y direction of the light guide 20. The two second surface sections 27a.2, 27b.2 also widen at least in places in the longitudinal direction x. At the output area 24, the light guide 20 exhibits a maximum width with regard to the function of fanning out the light. At the bottom of the light guide 20, a protrusion 26 is formed which at this point forms an edge offset (rebate) with the housing top 11 and seals this point between the light guide 20 and the housing top 11 against foreign bodies, in particular intruding hair. The protrusion 26 is even wider than the output area 24, such that the output area 24 may throughout be arranged flush with the housing or may form part of the housing. The protrusion 26 may in this case be arranged in the housing.

Fig. 2 additionally indicates a main direction of extension Y, in which the reflection surfaces 21 extend and in which the cutting device (not shown) extends. Furthermore, a flared portion y4 of the light guide 20 is indicated which the light guide 20 comprises in the longitudinal direction relative to an extension in the y direction. The flared portion y4 is a sort of widening, in particular in the shape of a fan. As a result of the flared portion y4, light, even if input thereof in the input area 23 is merely more or less punctiform, may be widened out and output in the output area 24 in the form of a fan.

Thanks to the geometry of the light guide 20, this is possible even in the case of a substantially punctiform light source such as for example an LED.

Indicated at the distal end 20a of the light guide 20 is a plane YZ in respect of which the output area 24 is curved. As a result of this convex curvature, when viewed in the direction of light propagation, on the one hand the light may be fanned out and on the other hand the light may be output in such a way that an area is lit up which, as spacing increases in the x direction, becomes wider (exhibits a greater y extension) than the output area 24.

Fig. 3a shows the light guide 20 in a direction of view in the longitudinal direction X. The input area 23 has a plane surface 23a, which is recessed relative to adjacent surfaces, i.e. forms a recess. The recess formed by the plane surface 23a may create space for further electronic components which may be arranged at this point in addition to the LED. The edge regions of the plane surface 23a or of the recess may in this case secure the printed circuit board in the X direction. A plurality of recesses may also be formed, these simplifying fastening of the light guide to the printed circuit board or the housing. The output area 24 has the width y2, which is greater than the width of the input area 23. The light guide 20 widens out from the input area 23 to the output area 24. The protrusion 26 takes the form of projections pointing laterally outwards, which may engage behind the housing top (not shown).

Fig. 3b shows the light guide 20 in a direction of view contrary to the longitudinal direction X. A maximum width y3 of the light guide 20 is present in the region of the protrusion 26. The protrusion 26 extends below the output area 24 along from the output area 24 and has at a central point on the central longitudinal axis M of the light guide 20 a centring element 26a, by means of which the light guide 20 may be mounted in a defined position in the housing. Tilting may also be prevented by means of centring element 26a.

Fig. 3c shows the light guide 20 in section in the xz plane, wherein the longitudinal direction x extends at least approximately parallel to the central longitudinal axis M. In addition to the features of the light guide 20 which have already been described, Fig. 3c shows the output area 24 with a convexity or a radius 24a, a contact surface 24b, a top 24c and a front side 24d. The front side 24d is arranged at an angle a relative to the longitudinal direction x and/or the central longitudinal axis M. The angle a here amounts to around 40 to 50 degrees, but may also be of a different magnitude. The output area 24 forms with its top 24c a recess which has a height zl relative to the upper reflection surface 21. The height zl preferably corresponds to a wall thickness of the housing (not shown) which comes to rest against the recess or the contact surface. At the distal end 20a, the light guide 20 has a distal reflection surface section 22b which is inclined relative to the upper reflection surface 21. The light guide 20 tapers in the region of the distal reflection surface section 22b, at least relative to the xz plane and viewed in the longitudinal direction.

Light is guided from the input area 23 to the output area 24 and directed at the distal end 20a between the upper reflection surface 21 and the distal reflection surface section 22b onto the front side 24d, the convexity 24a and the top 24c, primarily however onto the front side 24d. Due to the convexity 24a and/or the front side 24d arranged at the angle a to the central longitudinal axis M, the light may be somewhat refracted on emergence from the output area 24, such that it is deflected contrary to the z direction and lights up an area which lies above a cutting device (i.e. in front of the cutting device when viewed in the working direction), as indicated in Fig. 1. As a result of the convexity 24a and the top 24c, the light may in this case also be scattered contrary to the z direction, at least to a lesser degree, such that a user may be readily identify whether light is emerging.

The housing may rest against the contact surface 24b in such a way that the light guide 20 and the housing together form a planar top. In this way, the light guide 20 may form a part of the housing, in particular with its top 24c, and strictly speaking also with the convexity 24a, namely a distal edge of the housing.

Fig. 4a shows a sectional view of a hair-cutting device 1 with a housing 10 extending in the longitudinal direction X and a cutter head 40 arranged at the front thereof at a distal end of the housing 10. The cutter head 40 comprises a cutting device 41, in particular two cutters, which are displaceable relative to one another and of which at least one is mounted movably, in particular slidably. A light guide 20 is arranged directly beneath the housing 10, and projects with its distal end out of the housing 10 at the distal end of the housing 10, specifically with an output area which is designed as a projection or edge. The light guide 20 extends in the longitudinal direction X and lies with a proximal end against a printed circuit board fastened in the housing 10. The distal end and the proximal end of the light guide 20 will be explained in greater detail in Figures 5a and 5b with reference to the indicated detail views B and C.

The light guide 20 is set up to expand or fan out light in linear manner and to direct it onto the cutting device 41, wherein the cutting device 41 may be arranged or designed in linear manner. The light guide 20 is arranged in such a way in the housing 10 that the light guide 20 is stabilisable in an inner surface of the housing 10 and forms the front, distal end of the housing 10. In this case, the distal end of the light guide 20 is arranged opposite the cutting device 41 in visual communication with the cutting device 41. The light guide 20 has a central longitudinal axis M which is directed towards the cutting device 41.

Fig. 4b shows the housing 10, the cutter head 40 with the cutting device 41 and the light guide 20 (at least the front, distal end, which projects from the housing 10). The housing 10 has a top 11 and a bottom 12, and a bulge 11.2 is provided on the top 11, in which bulge 11.2 the light guide 20 is arranged. A distal end 11a of the housing top 11 is stepped. In the region of the bulge 11.2 in which the light guide 20 is arranged, the housing top 11 is shorter than in the region next to the bulge 11.2. In other words, the housing top 11 has a recess at the distal end 11a for receiving the distal end of the light guide 20. The output area 24 of the light guide 20 is designed as an arcuate light edge, which is set up to form a distal edge of the housing 10. The bulge 11.2 points towards the cutting device 41. The bulge 11.2 is curved such that the distal end 11a points at the cutting device 41.

Fig. 4c shows the bulge 11.2 in plan view. The housing top 11 has been fitted in the region of the bulge 11.2, and the light guide 20 forms a distal end of the housing top 11. The light guide 20 rests flush against the distal end of the housing top 11, both against the bulge 11.2 and against the housing sections arranged laterally next to the bulge 11.2. In other words, a distal end 20a of the light guide 20 is arranged in a plane with the distal end of the housing 10 or housing top 11 and optionally also (as illustrated) the housing bottom 12. In this arrangement, the light guide 20 may be arranged close to the cutting device 40. Curvature or arching of the housing top 11 about the z axis may also be used to integrate the light guide 20 conveniently into the housing 10. The light guide 20 is curved or arched about the z axis and is set up to fan light out or expand it onto the cutting device 40. An output area 24 of the light guide 20 is of arcuate design and forms a light edge on the housing. In this case, in the longitudinal direction X the light guide 20 has a geometry which diverges relative to the y direction. In other words, the light guide 20 widens out relative to the y direction, as indicated by the bulge 11.2 designed with corresponding geometry.

Fig. 5a is a detailed depiction (scale 5:1) of the distal end 11a of the housing top 11 together with the distal end 20a of the light guide 20. An output area 24 of the light guide 20 has an upper side 24c, which is arranged in a plane with an outer circumferential surface of the housing top 11. The light guide 20 is arranged between the housing top 11 and the cutter head 40. The light guide 20 rests with its distal end 20a against a holder 42 of the cutter head 40. The light guide 20 may in this case be wedged with its distal end 20a in between the housing top 11 and the holder 42. A support 34 is arranged between the holder 42 and the light guide 20, and the light guide 20 is supported on the support 34 via a lower reflection surface 22. The support 34 is a constituent part of the housing top 11. The support 34 is at least in places of L-shaped design in cross-section in an xz plane and has two support legs 34.1, 34.2 and a contact surface 34a, against which the lower reflection surface 22 rests. The support 34 secures the light guide 20 in the output area 24 in the y direction and in the z direction.

Fig. 5b is a detailed depiction (scale 5:1) of an input area 23 of the light guide 20. The input area 23 takes the shape in cross-section of a segment of a circle and, in absolute terms, takes the shape of a segment of a sphere, but may also have a different geometry. The input area 23 is arranged on a printed circuit board 30, on which a light source (not depicted explicitly) is arranged. The printed circuit board 30 is fastened to a partition 13, which is for example connected to the housing top 11. The printed circuit board is arranged between the partition 13 and the light guide 20 and is thus fixed in all three spatial directions. The light guide 20 has a projection 25, which, when the light guide is mounted, assumes an undercut-like function and is set up to protect the light source or the printed circuit board 30 from dirt, in particular hair. The projection 25 engages beneath the printed circuit board 30 such that the light source or the input area 23 may be partitioned off from the inside of the housing. The light guide 20 has a lower reflection surface section 22a which extends at least approximately parallel to an upper reflection surface 21. The reflection surface section 22a and the upper reflection surface 21 extend at least approximately at the same spacing from and in the same direction relative to the input area 23. In this way, (total) reflection within the light guide 20 may be improved.

List of reference signs I Hair-cutting device 10 Housing II Housing top 11a Distal end of the housing top 11.1 Inner surface of the housing top 11.2 Bulge 12 Housing bottom 13 Partition 20 Light guide, in particular light fan 20a Distal end 20b Proximal end 21 Upper reflection surface 22 Lower reflection surface 22a Lower reflection surface section 22b Distal reflection surface section 23 Input area 23a Plane surface 24 Output area 24a Radius or convexity 24b Contact surface 24c Upper side 24d Front side 25 Projection 26 Supporting member (rib, protrusion or projecting part) 26a Centring element 27a Right-hand lateral surface 27b Left-hand lateral surface 27a.1 First right-hand light-guiding surface section 'Z'lto.L First left-hand light-guiding surface section 27a.2 Second right-hand light-guiding surface section 27b.2 Second left-hand light-guiding surface section 28 Fastening means

30 Printed circuit board 31 Light source, in particular LED 34 Support 34.1 Support leg 34.2 Support leg 34a Contact surface 40 Cutter head 41 Cutting device, in particular cutter 42 Holder yl Width of cutter head y2 Width of output area of light guide y3 Maximum width of light guide y4 Flared portion of light guide L Incident light M Central longitudinal axis of light guide X Longitudinal direction Y Main direction of extension zl Height of recess or output area a Angle between longitudinal direction and front side

Claims

A hair clipping device (1) having - a housing (10) extending in a longitudinal direction (x); - a knife head (40) having a cutting device (41), the cutting device being oriented in a main extension direction (y); - a light source (31) arranged in the interior of the housing; and - a light guide (20) comprising a switch-on area (23) and a switch-off area (24) each for light from the light source and arranged to direct the light from the switch-on area to the switch-off area and point it towards the knife head (40), wherein the light guide ( 20) is arranged in the interior of the housing (10) in such a way that the cut-out area (24) can be arranged in optical communication with the cutting device (41), characterized in that the cut-out area has a convexity (24a) in such a way that at least some of the light can be focused towards the cutting device.

Hair clipping device according to claim 1, characterized in that a distal end (20a) of the light guide abuts against a distal end (11 a) of the housing.

Hair clipping device according to one of the preceding claims, characterized in that the cut-out area has a front face (24d) disposed at a definable angle with respect to the longitudinal direction (x).

Hair clipping device according to one of the preceding claims, characterized in that the light guide (20) is arranged in the housing in such a way as to ensure sealing of the switch-on and / or switch-off area (23, 24) relative to the surroundings.

Hair clipping device according to one of the preceding claims, characterized in that the light guide in the cut-out area (24) abuts against a support (42) of the knife head.

Hair clipping device according to one of the preceding claims, characterized in that the light guide in the cut-out area (24) is geometrically adapted both to the housing (10) and to the knife head (40).

Hair clipping device according to one of the preceding claims, characterized in that the engagement region (23) has a concave geometry which curves inwards and is flat with a large radius of curvature.

Hair clipping device according to one of the preceding claims, characterized in that the light guide has a proximal end (20b) which is wider than the switch-on area (23) and / or overlaps the switch-on area (23) in a proximal direction.

Hair clipping device according to one of the preceding claims, characterized in that the light conductor in the switch-on area (23) comprises a surface section (22a) which is oriented relative to the switch-on area in such a way that the light can be guided thereon by total reflection.

Hair clipping device according to one of the preceding claims, characterized in that the light source (31) is arranged on a fastening element (30) which is connected to the housing, the light guide having a projection which overlaps the fastening element (30).

Hair clipping device according to one of the preceding claims, characterized in that the housing (10) has a bulge (11.2) which is designed for at least partially accommodating the light guide.

Hair clipping device according to one of the preceding claims, characterized in that the light guide (20) becomes wider towards the cutting device (41) in the form of a fan.

Hair clipping device according to one of the preceding claims, characterized in that the light guide (20) has a light-transmitted cross-section, which in the cut-out area (24) is geometrically adapted to the geometry of the cutting device, where the switching area (23) in the main extension direction (y) has a width, there is less than one width (y2) of the cutout area (24) in the main extension direction.