CN110315577B

CN110315577B - Personal care device and method of manufacturing the same

Info

Publication number: CN110315577B
Application number: CN201910240173.3A
Authority: CN
Inventors: A·埃尔特
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 2018-03-29
Filing date: 2019-03-28
Publication date: 2021-09-03
Anticipated expiration: 2039-03-28
Also published as: EP3546155A1; JP2019171066A; JP6940545B2; EP3546155B1; CN110315577A

Abstract

The invention provides a personal care device and a method of making the same. The present invention relates to a personal care device, in particular an electric shaver, comprising a housing with a working head attached thereto and a display comprising a light source accommodated in the inner housing to emit light through transparent portions of the inner and outer housing, the display further comprising a display foil having portions of different transparency and/or different color forming a display symbol, the display foil being sandwiched between the transparent portions of the inner and outer housing. More specifically, the display foil may be glued to both the inner and outer shells by means of an adhesive on each of the opposite sides of the display foil.

Description

Personal care device and method of manufacturing the same

Technical Field

The present invention relates to a personal care device, in particular a hair removal device, such as an electric shaver or epilator, comprising a housing with a working head attached thereto, the housing comprising an inner shell and an outer shell, and a display comprising a light source accommodated in the inner shell to emit light through transparent portions of the inner and outer shells, the display further comprising a display foil having portions of different transparency and/or different color forming a display symbol, the display foil being sandwiched between the transparent portions of the inner and outer shells. The invention also relates to a method of manufacturing such a personal care device.

Background

Electric shavers and other hair removal devices, such as epilators, typically have one or more cutter elements driven in an oscillating manner by an electric drive unit, wherein the cutter elements reciprocate under a cutting foil, wherein such cutter elements or undercutters may have an elongated shape and may reciprocate along their longitudinal axis. Other types of electric razors use a rotating cutter element, which may be driven in an oscillating or continuous manner. The electric drive unit may comprise an electric motor or a magnetic linear motor, wherein the drive unit may comprise a drive train having elements such as an elongated drive transmission for transmitting the drive motion of the motor to the cutter element, wherein the motor may be received within the handle portion of the shaver.

On the other hand, when the motor is housed within the razor head, such a drive train extending from the housing into the razor head is not required. However, electrical connections, typically from a power source housed in the housing, extend into the razor head to supply power from the power source to the motor. Such a power source may be a power storage device, such as a battery or accumulator.

The housing containing the electric motor and/or the power supply usually comprises an elongated base element closed by a cover element to allow mounting and containing the electronic components within the housing. However, since the housing should form a sealed container for protecting the electrical components from liquid and moisture, a seal is provided between the base element and the cover element, wherein such a seal may comprise a sealing ring extending between the surfaces of the base element and the cover element facing each other.

Such a housing seal is also necessary in order to protect the other electronic components from liquids and moisture. For example, personal care devices typically include a display device for displaying various information to a user. Such displays may include symbols or other types of information indicating the state of charge of the battery, the state of cleaning, the need to replace, for example, the wear and tear of the tool head, the level of the application reservoir, such as care instructions, speed patterns, user patterns, or styling patterns.

Such a display device may comprise at least one light source, such as an LED, to emit light from inside the housing through a transparent portion of the housing, wherein such light may be directed through a display foil provided with more or less transparent portions and/or portions of different color to form the above-mentioned symbol, which is illuminated by light directed through said display foil. Although the light sources and the power and control elements connected thereto, such as electronic circuit boards, are received inside the housing to protect them from moisture, the display foils are sometimes located outside the sealed housing container to provide a brighter illumination of the display symbol with a richer contrast.

More specifically, the display foil may be located outside an inner envelope, which is sealed against moisture or liquid, but also inside an outer envelope surrounding or surrounding the inner envelope such that the display foil is sandwiched between the inner and outer envelope. Such double or multiple shell construction of the housing is sometimes required in order to hide the functional structure of the inner shell and to provide good operation, aesthetic appearance and modular configuration of different types of devices. Each of the inner and outer shells may be individually adapted for different functions. For example, the inner housing may form a functional platform for housing electronic components to protect against moisture and to position drive train elements and support the work head, while the outer housing may meet other needs, such as forming an ergonomic handle with an organic shape and a non-slip surface or attractive appearance.

However, such outer shells are sometimes not sealed against the influence of moisture or liquids or foam or gel and may therefore come into contact with a display foil arranged between the outer shell and the inner shell. Such contact of moisture with the display foil may impair visibility of the display symbol or worse, the function of the display foil due to, for example, dissolving the boundary between the transparent portion and the opaque portion.

Furthermore, when positioning the display foil between the inner and outer housing portions, it is sometimes difficult to accurately align the symbols of the display foil with the light sources accommodated in the interior of the inner housing, since manufacturing tolerances may lead to misalignment of the display foil. Even with small misalignments, the illumination of the symbol may be severely compromised due to light diffusion or stray light or shadows. Since there are typically a plurality of symbols positioned very close to each other, the light sources are also arranged in a rather dense matrix, so that even a small misalignment may cause light emitted from the light source associated with a first symbol to deviate and scatter to a second symbol.

For example, US 2009/0025229 a1 shows a personal care device of the above-mentioned type, disclosing a drive unit for a cutter element of an electric shaver, wherein the drive unit comprises a transmitter pin extending from a shaver housing towards a shaver head. A similar device is known from US 7,841,090B 2.

Further electric razors are known from e.g. US 3,748,371B, FR 1391957A, GB 811,207B and US5,704,126B.

Disclosure of Invention

It is an object of the present invention to provide an improved personal care device, such as a hair removal device like an electric shaver or an epilator, which avoids at least one of the drawbacks of the prior art and/or further develops the existing solutions.

It is a more specific object of the invention to provide a cost-sensitive, easy-to-manufacture personal care device, such as a hair removal device, like an electric shaver or epilator, having a bright display for displaying information and being sufficiently sealed against the influence of liquids.

It is a further object of the invention to provide an improved hair removal device, such as for example a shaver, having a sealed container housing for accommodating electronic components such as an electric motor and/or a power supply, and a display which is rich in contrast and provides good visibility.

More specifically, it is an object of the invention to combine an easily visible display with a sealing of the housing of the personal care device and a protection of the display from moisture even if there are tolerances in the shape and/or dimensions of the housing elements to be connected and/or variations in the mounting force with which the housing elements are pressed against each other due to tolerances and/or errors in the assembly process.

In order to achieve at least one of the above objects, it is suggested to provide a personal care device as described above with sealing of the display foil to both the inner housing element and the outer housing element to protect the display foil from liquid and moisture. More specifically, the display foil may be glued to both the inner and outer shells by means of an adhesive on each of the opposite sides of the display foil. Due to this adhesion of the display foil to the outside of the inner envelope and the inside of the outer envelope, water or other liquids and moisture or foam or gel is prevented from creeping onto the display foil surface, thereby preventing the visibility from being impaired or the display foil from becoming defective.

In order to compensate for tolerances in the distance of the inner surface of the outer shell from the outer surface of the inner shell and/or to compensate for movements of the inner and outer shells relative to each other and/or bending of the shell due to deformations caused by the clamping force, an adhesive foam, such as PE foam or PU foam, may be used as an adhesive to glue the display foil to the inner or outer shell.

After attaching the display foil to the inner envelope, the display foil may be provided with the symbol to be illuminated by means of, for example, laser treatment of the display foil. Applying the symbol to the foil after fixing the foil to the inner housing helps to avoid misalignment of the symbol with respect to the inner housing and the component received therein, such as a light source.

According to yet another aspect, the inner housing may be provided with opaque light blocking barriers on the inside of the inner housing to limit transmission of light emitted by a light source associated with a transparent housing portion aligned with a display symbol only to the display symbol and to prevent other symbols from being illuminated by stray light or scattered light originating from such light source.

These and other advantages will become more apparent from the following description with reference to the drawings and possible examples.

Drawings

Fig. 1 is a perspective view of an electric shaver, wherein the shaver is connected to a handle by means of a support structure,

fig. 2 is a schematic exploded view of a housing of an electric shaver, showing a shell-like structure of the housing comprising an outer shell and an inner shell and a display foil arranged therebetween,

fig. 3 is a perspective exploded view of the inner housing of fig. 2, wherein an electronic core component including an LED array of the display is to be inserted into an elongated cup-shaped base element of the inner housing,

fig. 4 is a cross-sectional view of an electric razor handle showing the arrangement of the display foil between the inner and outer shells and the arrangement of the light source and light-shielding fence in the inner shell,

fig. 5 is a schematic cross-sectional view of a display foil and adhesive layers securing the display foil to an inner and an outer shell, wherein according to a first aspect, two transparent adhesive layers completely covering opposite surfaces of the display foil bond the display foil to the inner and outer shell,

fig. 6 is a schematic cross-sectional view of a display foil and an adhesive layer similar to fig. 5, wherein the bottom side of the display foil is bonded to the inner envelope by means of a transparent adhesive layer completely covering the display foil, and the top side of the display foil is bonded to the outer envelope by means of an adhesive layer, said adhesive layer having a window keeping the display area of the display foil open,

fig. 7 is a schematic cross-sectional view, similar to fig. 5, of a display foil and an adhesive layer, wherein the top side of the display foil is bonded to the outer envelope by means of a transparent adhesive layer completely covering the display foil, and the bottom side of the display foil is bonded to the inner envelope by means of an adhesive layer, said adhesive layer having a window keeping the display area of the display foil open,

fig. 8 is a schematic cross-sectional view of a display foil and an adhesive layer similar to fig. 5, wherein the bottom side of the display foil is bonded to the inner envelope by means of a transparent adhesive layer completely covering the display foil, and the top side of the display foil is bonded to the outer envelope by means of an adhesive foam layer, said adhesive layer having a window keeping the display area of the display foil open,

fig. 9 is a schematic cross-sectional view of a display foil and an adhesive layer similar to fig. 5, wherein the top side of the display foil is bonded to the outer shell by means of a transparent adhesive layer completely covering the display foil, and the bottom side of the display foil is bonded to the inner shell by means of an adhesive foam layer, said adhesive layer having a window keeping the display area of the display foil open,

Detailed Description

According to an aspect, to achieve at least one of the above objects, it is suggested that a personal care device seals a display foil arranged between an inner and an outer shell to an inner surface of the outer shell and to an outer surface of the inner shell. More specifically, the display foil is glued to both the inner and outer shells by means of an adhesive on each of the opposite main surfaces of the display foil, such that the outer shell is glued to the inner shell via said display foil. Since both surfaces of the display foil are thus glued to the inner and outer shells, water or other liquids and moisture are prevented from creeping onto the display surface of the display foil, thereby preventing the visibility of the display symbol from being impaired and the display foil from becoming defective.

More specifically, in order to prevent water or moisture from creeping onto the display symbol, the adhesive may form at least a closed sealing ring around the area of the display foil in which the display symbol is arranged, wherein such a closed sealing ring may be along the outer edge of the display foil. Basically, such a closed sealing ring formed by adhesive may be provided on each opposite side of the display foil, so that the central areas of both sides of the display foil may be kept open. However, in an alternative form, at least one of the main surfaces of the display foil may be completely covered by the adhesive and glued completely to the respective housing element, such that the display foil is in complete contact with the housing at least on one side.

More specifically, on one side of the display foil, the adhesive may form a transparent adhesive layer covering at least a major part of the display foil, including the display area in which the display symbol is arranged, while on the other side of the display foil, the adhesive may form an adhesive layer having a window to keep the display symbol open or uncovered. In such a window of the adhesive layer, the display foil is not covered by the adhesive and may be spaced apart from a transparent casing portion covering the display foil.

The substantially complete gluing of at least one side of the display foil to the housing, i.e. the whole surface area of said at least one side or at least a major part of the surface area of said side, is covered by an adhesive and glued to said housing, helping to maintain the desired shape of the display foil and preventing wrinkling or undulation or buckling or other undesired deformations of the display foil.

Both sides of the display foil may be glued substantially completely to the inner and outer envelope, wherein in this case the display foil is glued to the inner and outer envelope using a transparent adhesive such that light may be transmitted through the transparent adhesive layer, in particular in the area of the display symbol.

Such a windowed adhesive layer may be provided on the top surface of the display unit to fix the display foil to the housing, when one of the adhesive layers is provided with a window such that substantially the central part of the display unit is not glued to the respective housing element. In an alternative, such a windowed adhesive layer may be provided on the bottom side of the display foil to connect the display foil to the inner housing.

Such an adhesive layer having a window portion that holds open a display foil in which a display symbol is arranged may be composed of or comprise an opaque adhesive material. The use of such an opaque adhesive material forming a window frame surrounding the display area of the display foil can prevent scattered light from irradiating other portions than the display area, and thus can improve the visibility of the irradiated symbol.

According to a further aspect, the adhesive for gluing the display foil to the inner and/or outer shell may comprise an adhesive foam and/or be made of a foam material. For example, Polyurethane (PU) or Polyethylene (PE) foam may be used to fixedly attach the display unit to the inner or outer shell. The adhesive foam may be advantageous in order to compensate for tolerances in the distance of the inner surface of the outer shell from the outer surface of the inner shell and/or to compensate for movements of the inner and outer shells relative to each other which may occur, for example, due to bending of the shell and/or clamping of the shell with excessive force and/or to avoid the generation of air bubbles between the two glue layers. Advantageously, the adhesive foam may be resilient and/or deformable to allow for such compensation. Furthermore, such an adhesive foam may easily compensate for uneven portions of the surface of the housing and provide a smooth surface that retains the display foil.

In particular, the above-described adhesive layer having a window that holds open a display foil region in which a display symbol is provided may be formed of such an adhesive foam.

In order to avoid excessive forces to adhere the display foil to the display foil or even to loosen the display foil or to detach the display foil from the interior and/or the housing, it is advantageous to provide a multi-piece structure for the housing. More specifically, the housing may be composed of a plurality of housing parts, wherein the housing display part with the display foil attached thereto may form a substantially plate-like insert received in a window of the other housing part, which helps to avoid transmission of forces applied to said other housing part to said housing display part. In other words, the housing display member may form a window glass to be inserted into the window frame formed by the other housing member. More specifically, the housing display part forming the above-mentioned insert may be inserted into the window of the other housing part from the inside of the housing, so that the housing display part may adhere to the display foil even if the other housing part with the window is moved away from the display foil. More specifically, another housing part having the window may cover the housing display part from the outside of the housing together with the edge portion of the window.

For ease of manufacturing, but still receiving a precise alignment of the display symbol with the light source received inside the inner housing, the display foil may be provided with the display symbol after having been attached to the inner housing. More specifically, when manufacturing and/or assembling the personal care device, the flat display foil, which does not yet have a display symbol, may be glued onto the outer surface of the inner shell. After the display foil has been attached to the inner envelope by means of gluing, a marking process can be applied to the display foil in order to produce the desired display symbol. More specifically, a laser treatment process may be used in order to provide the desired symbol for the display foil attached to the inner housing.

The display foil may comprise a laser active layer. For example, a transparent foil with a laser active layer that becomes opaque when a laser is applied thereto may be used. In an alternative, the laser active layer may initially be opaque, e.g. black, wherein the laser active layer may be configured to become transparent in the portion affected by the laser beam. By laser activation it is also possible to apply the laser process after the razor is finally ready for manufacture and just before the razor is custom-packaged for a specific razor type by applying a specific type of display foil activation process (e.g. if e.g. the razor type differs only by the symbols shown on the laser display). Through the process, the inventors of the finished product are reduced.

Other processing techniques may be used to mark the display foil with a desired symbol (e.g., application of radiation to the foil via a mask).

Providing the display symbols after attaching the display foil to the inner housing not only facilitates accurate alignment regardless of tolerances in positioning the foil to the housing, but also allows for ease of logistics, avoiding the need to stock different display foils pre-configured for different models of personal care devices, thus reducing the number of different components required and making the components required for assembling the embodiments easier to deliver in time.

After the symbol has been formed on the display foil, the housing may be glued to the display foil. Thus, the manufacturing process may include the following three steps performed in sequence, with optional other intermediate processing steps in between: the flat display foil is glued to the inner envelope, the display foil is marked with the symbol to be displayed, and then the outer envelope is glued to the marked display foil. The optional intermediate step may comprise, for example, a heating step for accelerating the hardening of the adhesive or a cooling step after laser marking the display foil.

In order to facilitate a bright and accurate illumination of the symbol of the display foil without illuminating adjacent areas of the display foil, the inner envelope may be formed to comprise a transparent portion and an opaque portion. More specifically, the inner envelope may comprise a transparent portion aligned with and below the display symbol of the display foil, and an opaque portion surrounding said transparent portion, which may have a ring shape and/or may form a barrier fence preventing light passing through the transparent portion from spreading to other portions adjacent to the display symbol.

More specifically, the inner shell may be formed as a bi-component or multi-component part comprising portions of different materials. For example, the inner shell may be a molded plastic part made of two different plastic parts, one of which is transparent and the other of which is opaque.

When the display foil comprises a plurality of display symbols which may be arranged in a regular pattern, such as a symbol matrix, the inner housing may have a plurality of transparent portions aligned with the positions of the display symbols, wherein each of said transparent housing portions may be at least partially surrounded by an opaque housing portion. The opaque housing portions separating the transparent housing portions from each other may form a mesh or grid-like opaque structure that separates the transparent portions of the inner housing that are aligned with the display symbols. For example, the transparent portion of the inner shell may be formed from a transparent hard plastics material component, while the opaque mesh-like structure may be formed from an opaque soft plastics material component.

In addition to or instead of such a wall structure of the inner envelope comprising transparent and opaque portions, a shielding barrier structure may also be provided between the inner surface of the inner envelope and the light source. More specifically, such a barrier structure on the inner side of the inner envelope may comprise at least one non-transparent sleeve surrounding the at least one light source and extending from the light source to the inner surface of the inner envelope, wherein the longitudinal axis of such a sleeve may extend substantially perpendicular to the inner envelope and/or the display foil and/or substantially parallel to the main emission axis of the light source.

When there are a plurality of light sources associated with a plurality of display symbols, a plurality of such sleeve-like obscuration barriers may be provided so as to form a light pipe which directs light from each light source to its associated display symbol and prevents such light from propagating towards another display symbol. Likewise, when the display symbols and the light sources associated therewith are arranged in a regular pattern (such as a matrix of light sources), the sleeve-like obscuration barrier may form a grid-like or net-like structure of opaque material having light passages formed through recesses in the material and running from the light sources to the respective display symbol, more particularly the transparent portion of the inner envelope associated with such a display symbol.

The light sources may be arranged on a common circuit board to provide electrical power to and/or control the light sources. A sleeve-like barrier forming a light pipe may extend between such a circuit board and the inner housing, wherein the barrier structure may be attached to the circuit board and/or the inner housing in a fixed manner, e.g. by means of gluing or by means of press-fit contacts.

In order to compensate for the uneven surface of the circuit board and/or the inner case surface as described above, the barrier structure may be formed of a foam material, allowing the circuit board surface and/or the inner case to be completely contacted regardless of the uneven portion of the inner case. More specifically, the barrier structure may be formed of a sponge material, such as foam rubber or sponge rubber, which may adapt the profile of said barrier structure to the contact surface.

The inner housing may form a sealed, in particular waterproof, container in which the motor and/or the battery or the accumulator or other power source and/or the electronic control unit for controlling the light source of the motor and the display can be received and which is protected from liquid and moisture, wherein the container may have a tub-like structure and be formed by an elongated can or cup having a closed bottom and an open top side, wherein the motor, the electronic control unit and the battery can be completely received within such a cup element of the inner housing, which cup element, at its open top side, can be closed by means of a cover element, which cover element may form the front surface of the tub-like container forming the inner housing.

Thus, the barrel container forming the inner shell may have a two-piece construction comprising only two parts (i.e., the cup element and the lid element described above). This two-piece construction of the inner shell significantly reduces the sealing force required to waterproof the container. In particular, it may be sufficient to use only one annular seal to seal the interface between the cup element and the lid element, wherein such an interface may have a circular configuration, although other profiles such as an oval or elliptical profile are also possible.

The cup element may comprise a transparent portion aligned with the display foil.

The cup-shaped base element may have an elongated configuration extending over substantially the entire length of the inner shell and may have a length corresponding to at least 80% or 90% of the length of the inner shell and/or the stem, while the cover element may have a length less than 20% or less than 10% of the length of the inner shell and/or the stem. The cover element may thus have a disc-like or plate-like configuration, wherein it may have a slightly dome-like or convex profile.

A connector for connection to a support structure of a razor head may be provided on the above-mentioned cover member.

The lid element and the cup element of the inner shell may be rigidly connected to each other, wherein various known types of connection techniques may be used, such as a positive fit, a threaded connection, welding, gluing and/or a snap fit.

In order to hold the display and/or the motor and/or the electronic control unit and/or the light source arrangement of the battery in place within the inner housing, a support frame to which the above-mentioned components may be attached may be inserted into the cup element and may be held in place, wherein e.g. slidable guiding elements such as guiding grooves and/or guiding protrusions may be provided. Such a support frame may be formed by or comprise a circuit board carrying the light sources and/or forming part of the electronic control unit.

To facilitate sealing of the inner shell, the inner shell may have only one opening, which may be an opening in the cover element, through which the shaft protrudes. Alternatively, a second opening may be present in the end opposite the cover element, which second opening may be provided for a charging connection. However, such second openings may be avoided by integrating the charging connector into the inner housing (e.g., by molding the charging pins as an integral part of the inner housing).

To allow communication with the control unit inside the inner housing, the inner housing and/or the outer housing may comprise soft material portions that are allowed to deform in order to activate a switch located in the inner housing.

In order to allow access to the above-mentioned soft material portion associated with the switching means of the inner shell, the outer shell may also have a soft material portion and/or a recess or opening through which the soft material portion of the inner shell may be deformed.

The outer shell may have a two-piece or three-piece or multi-piece shell structure comprising a plurality of shell elements that may be connected to each other and cover different portions of the inner shell. In particular, the outer shell may comprise two shell elements extending on opposite sides of the inner shell and connectable to each other. Such housing elements may have a substantially-roughly-trough-like or chute-like profile such that both housing elements may substantially completely surround the inner shell.

In addition to such a housing element, the housing may also comprise a ring element, which is connected with at least one of the above-mentioned housing elements. Such a ring-shaped element may contribute to a rigid, robust housing structure, wherein such a ring-shaped element may be positioned at the end of the housing facing the razor head. More specifically, such an annular element may surround the shaft and may have an inner diameter that is significantly smaller than the maximum diameter of the inner shell.

When considering the handle as a whole, the handle may have an elongated shape, and the cross-section of the handle may increase substantially continuously from a bottom surface of the handle to a top surface of the handle opposite to said bottom surface of the handle. In other words, the cross-section of the handle may continuously increase towards the razor head. The cross-sectional shape may vary, wherein such cross-sectional shape may be substantially rounded and/or circular and/or elliptical and/or oval. "substantially continuously" does not exclude portions such as display members or operation-critical portions where the cross-section is not increased. However, when larger proportions are considered, the cross-section of the handle may increase from the bottom end portion to the top end portion.

Furthermore, the drive transmitter may comprise a shaft or shaft-like elongated drive element extending from the handle to the interior of the razor head.

In order to convert a rotational oscillation of such a shaft as described before into a linear oscillation of the at least one cutter element, a crank arm may be attached to the shaft, wherein such a crank arm may be positioned within the razor head and/or may support at least one drive pin for driving the cutter element. For example, such a drive pin may extend substantially parallel to the shaft and may be fixedly attached to the crank arm to extend eccentrically with respect to the axis of the shaft. When the crank arm extends in its neutral position substantially perpendicular to the desired linear oscillation of the cutter element, such a drive pin moves along a curved path tangential to the desired cutter element oscillation, thus performing an approximately linear oscillation.

These and other features will become more apparent from the examples shown in the drawings. As can be seen in fig. 1, the shaver 1 may have a shaver housing 300 forming a handle 2 for holding the shaver, which handle may have different shapes, such as-roughly-substantially cylindrical or box-shaped or bone-shaped, allowing an economical grasping or holding of the shaver, wherein such a shaver handle 2 has a longitudinal handle axis 20 due to the elongated shape of the handle, see fig. 1.

More specifically, the handle 2 may have a rounded or circular or oval or elliptical cross-sectional shape, wherein a mixture of these shapes is possible. Regardless of the cross-sectional shape, the cross-section may increase continuously from one end of the shank to the other.

On one end of the handle 2, an electric razor head 3 is attached to the handle 2, wherein the razor head 3 may be swingably supported about a rotation axis 7 and about a tilt axis 11, which rotation axis 7 and tilt axis 11 may extend substantially perpendicular to each other and to the aforementioned longitudinal handle axis 20.

When considering a rectangular spindle 40 of the razor head 3, the axis of rotation 7 may extend parallel to such spindle 40, while the tilt axis 11 may extend perpendicular to such spindle 40. Such a main axis 40 may be considered to extend parallel to the larger side surface of the razor head 3 and/or parallel to the longitudinal axis of the elongated cutter element and/or parallel to the reciprocation axis 8 and/or substantially perpendicular to the longitudinal handle axis 20.

The razor head 3 may comprise a pair of elongate cutter units 100, each comprising an elongate cutter element which may be driven in a reciprocating manner along a reciprocating axis 8 which may extend parallel to the aforementioned spindle 40. The cutter element may engage with and reciprocate under a shear foil covering the cutter element.

As can be seen from fig. 1 to 3, the razor head 3 is supported on the handle 2 by means of a support structure 30.

In addition to said support structure 30, an elongated drive transmitter may extend from the handle 2 into the razor head 3 for connecting the cutter elements to a motor 93, which may be accommodated inside the handle 2. Such an elongated drive transmitter 9 may comprise a shaft 90 which may be driven to rotate in a reciprocating manner, i.e. back and forth to a certain extent. The crank element may be rotationally fixed to said shaft 90 and housed inside the razor head 3. Such a crank element may rigidly support the drive pin of each of the cutter elements. In the neutral position of the shaft 90, the crank element may extend transversely to the longitudinal axis of the elongated cutter element, such that the drive pin moves back and forth along the longitudinal axis of the cutter element. More specifically, such a drive pin performs a movement along a segment of a circle. However, since the rotational oscillation has a finite amplitude and the circular segment is tangential to the longitudinal axis of the cutter element, this movement can be considered to approximate a linear movement along the longitudinal axis of the cutter element.

As can be seen in fig. 3, the housing 300 forming the handle 2 may have a double shell structure comprising an inner shell 301 and an outer shell 302 (comprising

parts

305, 304, 302d) surrounding said inner shell 301.

The inner housing 301 accommodates the above-mentioned motor 93 and, in addition, an electrical storage device such as a battery or an accumulator, and an electronic control unit, see fig. 3, wherein the inner housing 301 may form a waterproof container protecting such components from liquid and moisture.

More specifically, the inner shell 301 may have an elongated barrel-like structure, comprising a cup-shaped or pot-shaped base element 306 with a closed bottom and an open top surface, wherein such base element may extend substantially over the entire length of the handle 2, see fig. 2 and 3.

The base element 306 is closed at its open top side by a cover element 307, which may have a plate-like or slightly dome-like shape and which, when closing the base element 306, forms a front side of the inner housing 301 facing the razor head 3.

The aforementioned cover element 307 comprises an opening through which the shaft 90 penetrates the housing, wherein the cover element 307 is sealed against said shaft 90 and against the cover element 307 by means of suitable seals, such that the inner shell 301 forms a watertight container.

As can be seen in fig. 3, charging connectors such as charging pins 310 may protrude from the bottom side of the cover element 307 in order to allow charging of the battery inside the inner housing 301.

The inner casing 301 may comprise at least one soft material portion 309, which may be associated with an electronic switching device inside the inner casing 301.

As can be seen in fig. 3, the outer shell 302 may have a shell structure comprising a pair of

elongated shell elements

304 and 305, which together may substantially completely surround the inner shell 301. The

housing elements

304 and 305 may extend substantially over the entire length of the inner shell 301 and/or the handle 2.

The

housing elements

304 and 305 may be positioned on opposite sides of the inner shell 301 and may be connected to each other such that they together form a clamping surface of the generally conical or cylindrical shank 2.

Furthermore, the outer housing 302 may comprise a ring-shaped element 303 at least partially forming a top side surface of the outer housing 302 facing the razor head 3, wherein said ring-shaped element 303 may have an inner diameter substantially smaller than a maximum outer diameter of the inner housing 301. The ring element 303 is connected to at least one of the

housing elements

304 and 305, and may cover a ring portion of the cover element 307 of the inner housing 301.

Furthermore, there is a display 500 for displaying various information useful to a user of the device, wherein such a display 500 may be arranged at the housing 300, thereby forming the handle 2. Such a display 500 may include a plurality of display symbols 501a-n to indicate information such as the load status of the device battery, the cleaning status, the last shave time, or other information as previously described.

The display 500 comprises a display foil 502, which may comprise transparent and non-transparent parts forming the symbol or parts of different colors forming such symbols 501a-n, wherein a light source 503, such as an LED, may emit light to illuminate the symbol of the display foil 502.

As can be seen from fig. 3 to 9, the display foil 502 may be located between the inner and

outer shells

301, 302, wherein the inner and

outer shells

301, 302 may comprise transparent portions allowing light emitted from a light source 503, which may be accommodated inside the inner shell 301, to be transmitted through the inner shell 301, the display foil 502 and the outer shell 302.

More specifically, the housing 302 may include a transparent housing display member 302d, which may be one of the components of the aforementioned housing structure and housing elements thereof. The housing display member 302d may have dimensions comparable to the dimensions of the display foil 502 and/or may cover substantially the entire display foil 502.

As can be seen in fig. 3, the housing display component 302d may form an insert that may be inserted into a window portion of another housing component, which may be formed by one of the housing elements 304 described previously. Advantageously, the case element 304 (the edge of the window portion thereof forms a kind of window frame) may cover the outside of the outer case display part at the edge portion of the outer case display part 302. In other words, the housing display section 302d can be inserted into the window portion of the case member 304 from the inside of the case member 304. Thus, the force pushing the outer housing 302 away from the display foil 502 is not transmitted to the outer housing display member 302d and/or does not damage the adhesion of the display foil 502 to the inner and outer housing, as described below.

The inner shell 301 may also have a transparent portion 301d, which may form an integral part of the aforementioned base element 306. More specifically, the inner housing 301 may have a plurality of transparent portions in the area facing the display foil 502. Such a plurality of transparent portions 301d may be aligned with the display symbols 501a-n such that the respective display symbol is positioned directly on the top surface of the respective transparent portion 301d at its center.

Said transparent portions 301d of the inner housing 301 may also be arranged in a matrix-like pattern corresponding to the matrix-like pattern of display symbols 501 a-n.

In order to avoid light scattering to the different display symbols, said transparent portions 301d of the inner housing 301 may be separated from each other by non-transparent (opaque) housing portions 301 o. When the transparent portions 301d are arranged in a matrix-like pattern, the opaque case portions 301o may form a mesh-like or net-like structure, thereby forming a barrier fence structure.

The inner shell 301 may be formed as a two-component or multi-component moulded plastic component, wherein for example the transparent portion 301d may be formed from a transparent hard plastic, while the grid-like barrier structure formed by the opaque shell portion 301o may be formed from an opaque soft plastic material.

As can be seen from fig. 4 to 9, the light sources 503, which may also be arranged in a matrix-like pattern corresponding to the pattern of display symbols 501a-n, may be supported on a circuit board 504, which may comprise electrical wires for supplying power to the light sources 503 and electronic circuit components for controlling said light sources 503.

As can be seen in fig. 3, the circuit board 504 including the light source 503 may be pre-assembled with the motor 93 and the battery compartment to form a pre-assembled mounting structure that may be inserted into the inner housing 301.

In order to avoid scattering and propagation of light in the region between the circuit board 504 and the inner casing 301, a light shielding barrier structure 505 may be provided between the circuit board 504 and the inner surface of the inner casing 301. Such a barrier structure 505 may comprise a sleeve for each light source 503, which sleeve surrounds the associated light source 503 and may extend from the circuit board 504 to the inner surface of the inner housing 301. When a plurality of light sources 503 are present, a plurality of sleeve-like obscuration barriers may be provided as barrier structures 505, said barrier structures 505 may have a matrix-like or grid-like or mesh-like structure, thereby providing a plurality of light pipes or light channels, each of which reaches an associated display symbol 501a-n from a light source 503.

Such an internal barrier structure 505 may be made of a resilient and/or spongy material such as rubber sponge and may be in full contact with the surfaces of the circuit board 504 and the inner shell 301. For example, the barrier structure 505 may be fixedly attached to the circuit board 504 and/or the inner shell 301 by means of, for example, gluing or press-fit contacts.

As can be seen in fig. 5 to 9, the above-mentioned display foil 502 is glued to the outer surface of the inner shell 301 and to the inner surface of the outer shell 302 by means of

adhesive layers

506 and 507 on each side of the display foil 502. 520 in fig. 5 to 9 refer to the black laser active layer and 521 to the white PET base foil.

Advantageously, at least on one side of the display foil 502, a continuous adhesive layer 506,507 is provided to completely cover the display foil 502, wherein such continuous adhesive layer may be made of a transparent adhesive to allow light to pass therethrough. By means of such a continuous full-size transparent adhesive layer, the display foil 502, or at least a major part thereof, is in full contact with the respective inner or outer housing surface, thereby preventing wrinkling or buckling or other undesired deformations of the display foil 502.

As can be seen in fig. 5, such full size

adhesive layers

506 and 507 may be provided on two opposite sides of the display foil 502.

In the alternative, only one side of the display foil 502 may be provided with such a continuous full-size transparent adhesive layer, while the opposite side of the display foil 502 may be glued to the respective housing part by means of a frame-like adhesive layer having a window that keeps the central portion of the display foil 502 open. The advantage of such a window is that the creation of air bubbles is minimized or avoided on each side, since the glue layer is not properly fixed to the housing, and the other side improves the light transmission.

As can be seen in fig. 6, the bottom side of the display foil 502 may be glued to the inner housing 301 by means of a transparent adhesive layer 506 completely covering the display foil 502, while the top side of the display foil 502 may be glued to the outer housing 302 by means of a frame-like adhesive layer 507 having a central window 507w keeping open a central portion of the display foil 502.

In an alternative, as shown in fig. 7, the bottom side of the display foil 301 may be glued to the housing 302 by means of said frame-like adhesive layer 506 having a central window 506w, while the top side of the display foil 502 may be glued to the housing 302 by means of a continuous full-size adhesive layer 507 completely covering the display foil 502.

The frame-shaped adhesive layer having the central window may be formed of an opaque adhesive.

As can be seen in fig. 8 and 9, such a frame-like adhesive layer with a central window may also be formed of an adhesive foam, such as PU foam or PE foam, in order to compensate for tolerances in the distance of the display foil 502 to the inner shell 301 or the outer shell 302. Such an adhesive foam layer may have a multi-layer structure, wherein the foamed material may form a central layer or an inner layer, wherein a tacky adhesive layer is provided on the opposite side and forms a surface of the adhesive foam layer, see fig. 8 and 9.

As can be seen in fig. 8 and 9, the adhesive foam layer may be provided on the top side of the display foil 502 to glue it to the outer shell 302, or may be provided on the bottom side of the display foil 502 to glue it to the inner shell 301. The other side of the display foil 502 of both examples of fig. 8 and 9 may be glued to the other housing part by means of a continuous, substantially full-size transparent adhesive layer.

As shown in fig. 5 to 9, the display foil 502 may comprise a laser active layer, which allows to generate the display symbols 501a-n in a laser processing step, wherein laser light is applied to the display foil 502.

Advantageously, such a laser treatment may be performed after gluing the display foil 502 to the inner housing 301. After applying laser markings onto the display foil 502 to form the display symbol, the housing 302, more specifically the housing display member 302d, may be glued onto the top surface of the display foil 502. As described above, the laser treatment may be applied at the end of the razor assembly process.

In a further manufacturing step, the

other housing elements

304 and 305 of the housing 302 may be assembled to form the housing 302.

As can be seen in fig. 2 and 3, the pre-assembled electronic core of the shaver (comprising the circuit board 504 on which the light source 503 is supported and optionally the motor 93 and the battery compartment) may be inserted into the inner housing 301 before gluing the display foil 502 onto the outer surface of the inner housing 301, wherein the inner housing 301 may be completely closed and/or sealed before gluing the display foil 502 onto the inner housing 301. In an alternative form, the display foil 502 may be glued onto the inner housing 301 and/or laser marking of the display foil may be achieved before inserting the electronic core comprising the circuit board 504 into the inner housing 301.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

Claims

1. A personal care device comprising a housing (300) having a working head (3) attached thereto, the housing (300) comprising an inner housing (301) and an outer housing (302), and a display (500) comprising a light source (503) accommodated in the inner housing (301) to emit light through a transparent inner housing portion (301d) of the inner housing (301) and an outer housing display member (302d) of the outer housing (302), the display (500) further comprising a display foil (502) having portions of different transparency and/or different color forming a display symbol, the display foil (502) being sandwiched between the transparent portions of the inner housing (301) and the outer housing (302), characterized in that the display foil (502) is glued to both the inner housing (301) and the outer housing (302) by means of an adhesive on each of the opposite sides of the display foil (502),

wherein on one side of the display foil (502) the adhesive forms a transparent adhesive layer (506,507) covering at least a major part of the display symbol of the display foil (502) including it, while on the opposite side of the display foil (502) the adhesive forms an adhesive layer (506,507) having a window (506w,507w) which holds open the display symbol and/or a central portion of the display foil (502).

2. The personal care device according to claim 1, wherein the adhesive on both sides of the display foil (502) is a transparent adhesive.

3. The personal care device of claim 1, wherein the adhesive layer (506,507) having the window (506w,507w) is made of an opaque adhesive.

4. A personal care device according to claim 1, wherein at least one side of the display foil (502) is glued to the housing (300) by means of an adhesive foam.

5. The personal care device of claim 1, wherein the adhesive layer (506,507) having the window (506w,507w) comprises an adhesive foam layer and/or an adhesive polyurethane foam layer and/or an adhesive polyethylene foam layer, and the window is disposed in an inner shell side.

6. A personal care apparatus as claimed in claim 1, wherein the housing (302) is constituted by a plurality of housing parts, wherein a housing display part (302d) glued with the display foil (502) forms a substantially plate-like transparent insert which is accommodated in a window frame portion of one housing part (304) of the housing (302).

7. The personal care apparatus of claim 6, wherein the one housing part (304) covers an outer surface of the housing display part with an edge portion of a window thereof at an edge portion of the housing display part (302 d).

8. The personal care device according to claim 1, wherein the inner housing (301) is a multi-component plastic molded part made of a transparent hard plastic material part forming the at least one transparent inner housing portion (301d) in alignment with the display foil (502) and an opaque material portion (301o) made of soft or hard plastic surrounding the transparent inner housing portion (301 d).

9. A personal care device according to claim 1, wherein the inner housing (301) comprises a grid-like barrier structure made of opaque material portions (301o) separating from each other a plurality of transparent inner housing portions (301d) aligned with the display symbols of the display foil (502), the barrier structure preventing light transmitted to one of the display symbols through one of the plurality of transparent inner housing portions (301d) from propagating and scattering towards one of the other display symbols.

10. A personal care device according to claim 1, wherein at least one light source (503) is surrounded by a sleeve-like light pipe (509) extending from the light source (503) to the inner surface of the inner housing (301), the light pipe (509) having a substantially straight longitudinal axis substantially parallel to the main emission direction of the light source (503) and substantially perpendicular to the display foil (502).

11. The personal care device of claim 10, wherein the light pipe (509) is made of a sponge material or of a rubber sponge and contacts the inner surface of the inner housing (301) and a surface of a circuit board (504) supporting the at least one light source (503).

12. The personal care device of claim 10 or 11, wherein a plurality of light sources (503) are arranged in a pattern corresponding to the pattern of display symbols, wherein a plurality of light pipes (509) are provided to confine light emitted by each of the plurality of light sources (503) to one of the plurality of display symbols, wherein the plurality of light pipes (509) are formed by a grid-like barrier structure made of an opaque material.

13. A method of manufacturing a personal care device according to any one of the preceding claims, the method comprising the steps of:

-fixedly attaching a flat display foil (502) to the inner housing (301),

-marking the display foil (502) with a display symbol by means of a marking process after attaching the planar display foil (502).

14. The method according to claim 13, wherein the marking process comprises applying a laser beam onto the display foil (502).

15. The method according to claim 13 or 14, wherein the marking process is applied after assembling the housing and all display components are mounted on the housing and/or laser beam activation of the display foil is applied through both the outer and inner shells.